Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Motomura Goro Last modified date:2019.06.11

Associate Professor / Faculty of Medical Sciences


Papers
1. Hiroyuki Hatanaka, goro motomura, Satoshi Ikemura, Yusuke Kubo, Takeshi Utsunomiya, Shoji Baba, Koichiro Kawano, Yasuharu Nakashima, Differences in magnetic resonance findings between symptomatic and asymptomatic pre-collapse osteonecrosis of the femoral head, European Journal of Radiology, 10.1016/j.ejrad.2019.01.002, 112, 1-6, 2019.03, Purpose: The purpose of this study was to assess the differences in magnetic resonance (MR) findings between the symptomatic and asymptomatic pre-collapse stage of osteonecrosis of the femoral head (ONFH). Materials and methods: This study reviewed 123 consecutive hips in 91 patients in the pre-collapse stage of ONFH based on plain radiographic findings. These 123 hips were divided into symptomatic and asymptomatic groups according to the pain domain score in the Harris hip score system. Bone marrow edema (BME), synovial fluid effusion, and subchondral fracture were evaluated using MR imaging. Odds ratios (ORs) were calculated between these three parameters and symptoms. The subsequent clinical course after MR examination was also assessed for each hip that could be followed more than 1 year. Results: Forty-six hips (37.4%) were categorized as symptomatic and 77 hips (62.6%) as asymptomatic. The prevalence of BME, synovial fluid effusion, and subchondral fracture were 87.0% (40/46), 80.4% (37/46), and 34.8% (16/46), respectively, in the symptomatic group, and 0%, 28.6% (22/77), and 0%, respectively, in the asymptomatic group, indicating significant differences between the two groups (p < 0.0001). Among these parameters, BME showed the highest OR with regard to the presence or absence of symptoms (BME, 965.8; joint effusion, 10.3; subchondral fracture, 83.9). Due to persistent pain and subsequent collapse, 30 of 35 (85.7%) symptomatic hips with BME subsequently underwent surgical treatment at a mean interval of 3.47 months after MR examination, while 25 of 66 (37.9%) asymptomatic hips without BME underwent surgical treatment at a mean interval of 20.7 months after MR examination. Conclusions: This study demonstrated that symptomatic pre-collapse ONFH diagnosed based on plain radiographic findings could be distinguished from asymptomatic pre-collapse ONFH by the presence of BME on MR imaging, and thus BME may be a sign of occult fracture..
2. Yusuke Kubo, goro motomura, Satoshi Ikemura, Hiroyuki Hatanaka, Takeshi Utsunomiya, Satoshi Hamai, Masanori Fujii, Jun-Ichi Fukushi, Yasuharu Nakashima, Effects of anterior boundary of the necrotic lesion on the progressive collapse after varus osteotomy for osteonecrosis of the femoral head, Journal of Orthopaedic Science, 10.1016/j.jos.2019.02.014, 2019.01, Background: Anterior localization of the necrotic lesion was recently proposed as an important factor for the occurrence of collapse even in medially located osteonecrosis of the femoral head (ONFH). We examined the effects of the anterior boundary of the necrotic lesion on progressive collapse after varus osteotomy for ONFH. Methods: We reviewed the outcomes of 31 hips in 27 patients with ONFH treated by transtrochanteric curved varus osteotomy (CVO) from 2000 to 2012 with a mean follow-up of 10.5 years. The occurrence of progressive collapse of the anterior necrotic lesion was defined as the presence of ≥2 mm collapse using follow-up lateral radiographs. Postoperative osteoarthritic change was defined as ≥1 mm progression of joint space narrowing on follow-up radiographs. The location of the anterior boundary of the necrotic lesion was assessed using the anterior necrotic angle (the angle between the midline of the femoral neck shaft and the line passing from the femoral head center to the anterior boundary of the necrotic lesion on a mid-slice oblique magnetic resonance image). Results: All hips had a postoperative intact ratio of ≥34% (percentage of the transposed intact articular surface of the femoral head to the weight-bearing area of the acetabulum after femoral osteotomy). Progressive collapse of the anterior necrotic lesion was seen in five hips (16%) during a mean of 2.2 years after CVO. Of these, four hips (80%) proceeded to develop osteoarthritic change at an average of 4.3 years after the collapse. Multivariate analysis revealed that the anterior necrotic angle was independently associated with progressive collapse of the anterior necrotic lesion as well as the postoperative intact ratio. Conclusions: This study suggests that hips with anterior localization of the necrotic lesion have a possible risk of progressive collapse of the anterior necrotic lesion after CVO, which can frequently lead to subsequent osteoarthritic change..
3. Hiroyuki Hatanaka, goro motomura, Satoshi Ikemura, Yusuke Kubo, Takeshi Utsunomiya, Shoji Baba, Yasuharu Nakashima, Volume of hip synovitis detected on contrast-enhanced magnetic resonance imaging is associated with disease severity after collapse in osteonecrosis of the femoral head, Skeletal Radiology, 10.1007/s00256-019-3158-y, 2019.01, Objective: To evaluate the relationship between the volume of hip synovitis detected on contrast-enhanced magnetic resonance imaging (MRI) and the disease stage of osteonecrosis of the femoral head (ONFH). Materials and methods: Sixty-three consecutive hips in 40 ONFH patients were reviewed using contrast-enhanced MRI. Ten unaffected hips in 10 patients with unilateral ONFH were used as controls. Based on the Japanese Investigation Committee system, these hips were classified according to stage and type. The volume and location of hip synovitis were semi-quantitatively measured on contrast-enhanced MRI. Clinicoradiological factors were statistically analyzed to determine the relationship with the volume of hip synovitis. Results: The mean synovial volume was significantly larger in ONFH hips (8,020 ± 6,900 mm3) than in controls (910 ± 1,320 mm3; p = 0.001). The area of synovitis in the anterior portion of the hip joint was double (mean: 2.17 ± 1.77) that in the posterior portion. The volume of synovitis was small in pre-collapse-stage hips (stage 1: 680 ± 690 mm3, stage 2: 1,460 ± 1,200 mm3), but significantly larger in post-collapse-stage hips (stage 3A: 7,820 ± 4,490 mm3, stage 3B: 13,850 ± 7,110 mm3; p < 0.001). Multiple regression analysis showed that disease stage was the only factor related to hip synovitis. Conclusions: Our study suggests that hip synovitis in ONFH might occur after femoral head collapse and worsen with collapse progression, mainly in the anterior portion..
4. Jun-Ichi Fukushi, Ichiro Kawano, goro motomura, Satoshi Hamai, Kenichi Kawaguchi, Yasuharu Nakashima, Does hip center location affect the recovery of abductor moment after total hip arthroplasty?, Orthopaedics and Traumatology: Surgery and Research, 10.1016/j.otsr.2018.06.022, 104, 8, 1149-1153, 2018.12, Background: In total hip arthroplasty (THA), placing the cup in an anatomic position is not always possible in case of deformities related to developmental dysplasia of the hip (DDH). Thus far, the influence of a hip center on the abductor moment after THA has not been clearly elucidated. Therefore, we performed a retrospective study to assess (1) how abductor muscle moment recovers postoperatively in THA and (2) whether acetabular cup position affects the recovery of abductor moment. Hypothesis: A high hip center affects the recovery of abductor moment of a dysplastic hip after THA. Patients and Methods: We evaluated 100 patients, who underwent unilateral primary THA, at 12 months postoperatively. The study included 86 women and 14 men, with a mean age of 65.5 ± 9.9 years (range, 40 to 86 years). Patients with secondary osteoarthritis due to DDH were included (Crowe 1: 76; Crowe 2: 15, Crowe 3:9, and Crowe 4: none). A cementless straight stem was implanted in all hips. Hip abductor moment was measured using a belt-stabilized hand-held dynamometer. The ratio of moment of the affected side to that of the contralateral side was calculated as moment ratio. The horizontal and vertical centers of rotation (H-COR and V-COR) (with respect to the inter teardrop line) and vertical shift (V-shift) (difference in V-COR between the affected hip and the contralateral normal hip) were determined. Results: At 6 and 12 months postoperatively, the abductor moment ratios were 95.1 and 94.7%, respectively. Significant negative correlation was observed between the postoperative abductor moment ratio and V-COR at 6 months postoperatively (r = −0.2436, p = 0.0238). Significant delay in the recovery of abductor moment ratio was observed in the groups with higher hip center (V-shift > 15 mm) (odds ratio = 12.7; 95% CI: 2.11–232.1, p = 0.0034) at 6 months postoperatively, which was fully recovered at 12 months postoperatively. Discussion: Superior placement of a hip center, more than 15 mm above the true hip center, delayed the recovery of abductor muscle moment after THA. Level of evidence: III, retrospective comparative study..
5. Takeshi Utsunomiya, goro motomura, Satoshi Ikemura, Yusuke Kubo, Kazuhiko Sonoda, Hiroyuki Hatanaka, Shoji Baba, Koichiro Kawano, Takuaki Yamamoto, Yasuharu Nakashima, Effects of sclerotic changes on stress concentration in early-stage osteonecrosis
A patient-specific, 3D finite element analysis, Journal of Orthopaedic Research, 10.1002/jor.24124, 36, 12, 3169-3177, 2018.12, Stress distribution remains unclear in early-stage osteonecrosis of the femoral head (ONFH). To clarify this issue, we generated patient-specific finite element models (FEMs) from 51 patients with ONFH. Patients’ hips were classified into three groups: ONFH without a sclerotic boundary (Stage 1, n = 6), ONFH with a sclerotic boundary (Stage 2, n = 10), and ONFH with both a sclerotic boundary and <2 mm collapse (Stage 3, n = 35). Four hips without ONFH were used as controls. Stress distribution in each FEM was compared with magnetic resonance imaging (MRI) and computed tomography (CT) results. Fifteen wholly resected femoral heads in Stage 3 hips were assessed by micro-CT. Furthermore, we histologically examined three Stage 2 femoral heads that subsequently developed subchondral fractures after FEM analyses. In all FEMs of both control and Stage 1 hip, stress was equally distributed on the femoral head surface. However, in all FEMs of both Stages 2 and 3 hips, stress was concentrated at the lateral boundary of the femoral head surface, corresponding to both a low-intensity band on T1-weighted MRI images and sclerotic changes on CT. On micro-CT, subchondral fractures consistently began at the lateral boundary with sclerotic changes, in which bone volume fraction was increased. Histology showed breakage of subchondral plates at the junction between necrotic and reparative zones. In early-stage ONFH, sclerotic changes caused stress concentration, which can trigger subchondral fractures at the lateral boundary. Clinical Significance: Our results will clarify the pathogenic mechanism of collapse in ONFH..
6. Yusuke Kubo, goro motomura, Satoshi Ikemura, Hiroyuki Hatanaka, Jun-Ichi Fukushi, Satoshi Hamai, Takuaki Yamamoto, Yasuharu Nakashima, Osteoclast-related markers in the hip joint fluid with subchondral insufficiency fracture of the femoral head, Journal of Orthopaedic Research, 10.1002/jor.24066, 36, 11, 2987-2995, 2018.11, Similar to the radiological findings in rapidly destructive arthrosis of the hip joint (RDA), subchondral insufficiency fracture of the femoral head (SIF) can result in progressive femoral head collapse of unknown etiology. We thus examined the osteoclast activity of hip joint fluid in SIF with progressive collapse in comparison with that in RDA. Twenty-nine hip joint fluid samples were obtained intraoperatively with whole femoral heads from 12 SIF patients and 17 RDA patients. SIF cases were classified into subgroups based on the presence of ≥2 mm collapse on preoperative radiographs: SIF with progressive collapse (n = 5) and SIF without progressive collapse (n = 7). The levels of tartrate-resistant acid phosphatase (TRACP)-5b, interleukin-8, vascular endothelial growth factor (VEGF), and matrix metalloproteinase (MMP)-9 were measured. The number of multinuclear giant cells at the subchondral region was histopathologically assessed using mid-coronal slice of each femoral head specimen. The median levels of all markers and the median number of multinuclear giant cells in SIF with progressive collapse were significantly higher than those in SIF without progressive collapse, while there were no significant differences in SIF with progressive collapse versus RDA. Regression analysis showed that the number of multinuclear giant cells was positively correlated with the level of TRACP-5b in joint fluid. The present study demonstrated the possible association of increased osteoclast activity with the existing condition of progressive collapse in SIF, which was quite similar to the findings in RDA, indicating that increased osteoclast activity may reflect the condition of progressive collapse in SIF as well as RDA..
7. Satoshi Hamai, Yusuke Kohno, Daisuke Hara, Kyohei Shiomoto, Mio Akiyama, Jun-Ichi Fukushi, goro motomura, Satoshi Ikemura, Masanori Fujii, Yasuharu Nakashima, Minimum 10-year clinical outcomes after periacetabular osteotomy for advanced osteoarthritis due to hip dysplasia, Orthopedics, 10.3928/01477447-20180806-04, 41, 5, 300-305, 2018.09, The purpose of this study was to examine the minimum 10-year clinical outcomes, including patient-reported and functional outcomes, of periacetabular osteotomy in patients with advanced osteoarthritis. A total of 46 hips in 44 patients with advanced osteoarthritis who underwent periacetabular osteotomy between 1992 and 2006 were retrospectively reviewed. Mean age at surgery was 47.5 years, and mean follow-up was 16.9±4.7 years. Survivorship was determined using the Kaplan-Meier method, and the associated risk factors for the endpoint-conversion to total hip arthroplasty less than 15 years after surgery-were evaluated. The Oxford Hip Score and the University of California, Los Angeles activity score were evaluated at final follow-up. The survival rates at 15 and 20 years after surgery were 80% and 59%, respectively. Multivariate analysis indicated that body mass index greater than 24 kg/m2 (P=.034; odds ratio, 1.72) was significantly associated with the endpoint as an independent risk factor. For 32 hips of 31 patients with preserved native joints at final follow-up, the Oxford Hip Score and the University of California, Los Angeles score averaged 41±5 and 5.2±1.8, respectively, equivalent (P=.28 and P=.215, respectively) to the scores of 14 hips of 13 patients with conversion to total hip arthroplasty (38±8.7 and 5.8±1.4, respectively). The results of this mid-term study may be useful for surgical decision-making among patients with advanced osteoarthritis who want to preserve native hip joints..
8. Yuko Uesugi, Takashi Sakai, Taisuke Seki, Shinya Hayashi, Junichi Nakamura, Yutaka Inaba, Daisuke Takahashi, Kan Sasaki, goro motomura, Naohiko Mashima, Tamon Kabata, Akihiro Sudo, Tetsuya Jinno, Wataru Ando, Satoshi Nagoya, Kengo Yamamoto, Satoshi Nakasone, Hiroshi Ito, Takuaki Yamamoto, Nobuhiko Sugano, Quality of life of patients with osteonecrosis of the femoral head
a multicentre study, International Orthopaedics, 10.1007/s00264-018-3897-8, 42, 7, 1517-1525, 2018.07, Purpose: Quality-of-life (QOL) assessments in patients with osteonecrosis of the femoral head (ONFH) have rarely been reported. This multicentre study aimed to elucidate the relationship between disease severity, including necrotic lesion type and radiological staging, and QOL, as well as between patients’ characteristics and QOL. Methods: Two hundred seventy-four patients with ONFH (108 females, 166 males; median age, 46 years) were asked to complete self-assessment QOL questionnaires including the Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire, Oxford Hip Score, and SF-12v2. Results: Patients with large necrotic lesion type or collapsed ONFH had low QOL scores. Among patients with non-collapsed lesions, patients with alcohol-associated ONFH had lower QOL scores than those with steroid-associated ONFH, those with bilateral ONFH had lower mental scores, and male patients had worse social condition scores. Among patients with collapsed lesions, middle-aged patients exhibited lower mental QOL, and a strong correlation was observed between social activity and mental health. Conclusion: Collapsed ONFH was associated with low QOL scores. Among patients with non-collapsed lesions, alcohol-associated ONFH, bilateral disease, and male sex were linked to low QOL scores..
9. Yusuke Kubo, goro motomura, Satoshi Ikemura, Kazuhiko Sonoda, Hiroyuki Hatanaka, Takeshi Utsunomiya, Shoji Baba, Yasuharu Nakashima, The effect of the anterior boundary of necrotic lesion on the occurrence of collapse in osteonecrosis of the femoral head, International Orthopaedics, 10.1007/s00264-018-3836-8, 42, 7, 1449-1455, 2018.07, Purpose: The location of the necrotic lesion is one of the important factors for collapse in osteonecrosis of the femoral head (ONFH). The significance of anterior localization has been little studied. This study evaluated the effects of anterior boundary of a necrotic lesion on collapse. Methods: We reviewed the outcomes of 113 consecutive non-collapsed asymptomatic hips in 98 ONFH patients with mean follow-up of 4.7 years (2.0–11.8) after the initial magnetic resonance (MR) imaging. The presence or absence of collapse was investigated using follow-up radiographs. The location of the anterior boundary of a necrotic lesion was assessed using the anterior necrotic angle between the midline of the femoral neck shaft and the line passing from the femoral head centre to the anterior boundary on mid-oblique MR imaging. Multivariate analysis was performed to identify risk factors for collapse, and further analyses were executed according to the lateral boundary of the necrotic lesion. Results: During the follow-up period, collapse was confirmed in 61 hips (54.0%). Multivariate analysis revealed that the anterior necrotic angle was independently associated with collapse as well as the lateral boundary of the necrotic lesion. When the lateral boundary was located at the middle third of weight-bearing portion (32 hips), that was generally categorized as a low risk of collapse, all five cases with anterior necrotic angle ≥ 79° developed collapse, whereas only one of 27 cases (3.7%) with an anterior necrotic angle < 79° developed collapse (p < 0.0001). Conclusions: This study indicates that ONFH patients with anterior localization of a necrotic lesion can develop collapse even if the necrotic lesion is medially located..
10. Kenyu Iwasaki, Takuaki Yamamoto, goro motomura, Kazuyuki Karasuyama, Kazuhiko Sonoda, Yusuke Kubo, Yasuharu Nakashima, Computed tomography findings of subchondral insufficiency fractures of the femoral head, Journal of Orthopaedics, 10.1016/j.jor.2018.01.044, 15, 1, 173-176, 2018.03, Objectives: The objective of this study was to describe the appearance of Subchondral insufficiency fracture (SIF) by computed tomography (CT). Methods: Images of 52 consecutive patients diagnosed with SIF were retrospectively reviewed. CT was available for five patients (7 cases). Results: Corresponding to a low-intensity band on MR images, a radiolucent or sclerotic band was observed on CT images. Conclusion: The present study is the first to report CT findings of SIF. A radiolucent or sclerotic band was observed on CT images. The results of the present study provide useful information for diagnosis of SIF..
11. Daisuke Hara, Satoshi Hamai, Keisuke Komiyama, goro motomura, Kyohei Shiomoto, Yasuharu Nakashima, Sports Participation in Patients After Total Hip Arthroplasty vs Periacetabular Osteotomy
A Propensity Score-Matched Asian Cohort Study, Journal of Arthroplasty, 10.1016/j.arth.2017.08.035, 33, 2, 423-430, 2018.02, Background: No studies have compared sports participation between total hip arthroplasty (THA) and periacetabular osteotomy (PAO) in matched Asian cohorts. We investigated sports participation and activity levels in Asian THA cohort, and compared them between THA and PAO cohorts. Methods: Multivariate analyses were applied to determine which factors were associated with postoperative sports participation and University of California-Los Angeles (UCLA) activity score in (1) 524 THA patients and (2) 487 acetabular dysplasia patients (295 THA patients and 192 PAO patients). In addition, postoperative sports participation and UCLA score were compared between 62 THA and 62 PAO patients after adjusting for baseline characteristics with propensity score matching. Results: Sports participation and UCLA score significantly increased after THA (P <.001 in both analyses). Preoperative sports participation was the factor most associated with both postoperative sports participation and UCLA score in both 524 THA patients and 487 acetabular dysplasia patients (P <.001 in all analyses). Multivariate analysis in 487 acetabular dysplasia patients demonstrated that THA, compared with PAO, was negatively associated with postoperative sports participation (P <.001), but not postoperative UCLA score (P =.22). THA patients showed significantly lower rate of postoperative sports participation (32.3% and 51.6%, respectively, P =.046), but not postoperative UCLA score (5.0 ± 1.6 and 5.2 ± 1.9, respectively, P =.47) compared with matched PAO patients. Conclusion: THA significantly increased both sports participation and activity levels. Both multivariate and propensity score-matched analyses showed that postoperative activity levels were comparable between THA and PAO cohorts..
12. Karasuyama, Kazuyuki; Motomura, Goro; Ikemura, Satoshi; Fukushi, Jun-ichi; Hamai, Satoshi; Sonoda, Kazuhiko; Kubo, Yusuke; Yamamoto, Takuaki; Nakashima, Yasuharu, Risk factor analysis for postoperative complications requiring revision surgery after transtrochanteric rotational osteotomy for osteonecrosis of the femoral head, JOURNAL OF ORTHOPAEDIC SURGERY AND RESEARCH, 10.1186/s13018-018-0714-4, 13, 2018.01.
13. Keisuke Komiyama, Jun-Ichi Fukushi, goro motomura, Satoshi Hamai, Satoshi Ikemura, Masanori Fujii, Yasuharu Nakashima, Does high hip centre affect dislocation after total hip arthroplasty for developmental dysplasia of the hip?, International Orthopaedics, 10.1007/s00264-018-4154-x, 2018.01, Background: To achieve sufficient socket coverage by the native bone, high placement of cementless acetabular cup is often required. We previously reported, using computer simulation, that higher hip centre improved the bone coverage but decreased the range of motion in total hip arthroplasty (THA) for patients with hip dysplasia. However, in a clinical setting, the correlation between the hip centre height and dislocation after primary THA is still unclear. We examined whether a high hip centre affects dislocation after THA. Methods: A total of 910 patients, with 1079 dysplastic hips, who underwent primary THA were retrospectively reviewed. The age at THA averaged 63.0 years and mean follow-up was 74.3 months. Vertical centre of rotation (V-COR) was defined as the distance from the head centre to the interteardrop line. Uni- and multivariate logistic regression models were applied to identify significant factors affecting dislocation. Results: Ten hips in nine patients (0.9%) had dislocation after THA. In univariate analysis, age at surgery and V-COR were significant risk factors for dislocation. Multivariate analysis identified advanced age at operation (odds ratio [OR] 1.8/5 years), Crowe classification (OR 15.6), V-COR (OR 3.1/5 mm), and femoral head size (OR 11.6) as independent risk factors for dislocation. Receiver operating characteristic curve analysis revealed the cutoff value of the V-COR for dislocation as 23.9 mm. Conclusions: A higher hip centre with the V-COR > 23.9 mm affected dislocation after THA for DDH. Our results would be useful for reconstruction of the hip centre, particularly with cementless acetabular cups..
14. Shoji Baba, goro motomura, Satoshi Ikemura, Kazuhiko Sonoda, Yusuke Kubo, Takeshi Utsunomiya, Hiroyuki Hatanaka, Yasuharu Nakashima, Femoral head fracture similar to slipped capital femoral epiphysis in an elderly woman with antecedent hip osteoarthritis after subchondral insufficiency fracture
A case report, Journal of Orthopaedic Science, 10.1016/j.jos.2017.09.009, 2018.01.
15. Koichiro Kawano, goro motomura, Satoshi Ikemura, Yusuke Kubo, Hiroyuki Hatanaka, Takeshi Utsunomiya, Shoji Baba, Yasuharu Nakashima, Subchondral insufficiency fracture of the femoral head in an elderly woman with symptomatic osteoarthritis of the contralateral hip, Journal of Orthopaedic Science, 10.1016/j.jos.2018.02.001, 2018.01.
16. Yuma Sakamoto, Takuaki Yamamoto, Nobuhiko Sugano, Daisuke Takahashi, Toshiyuki Watanabe, Takashi Atsumi, Junichi Nakamura, Yukiharu Hasegawa, Koichi Akashi, Ichiei Narita, Takeshi Miyamoto, Tsutomu Takeuchi, Katsunori Ikari, Koichi Amano, Atsuhiro Fujie, Toshikazu Kubo, Yoshifumi Tada, Ayumi Kaneuji, Hiroaki Nakamura, Tomoya Miyamura, Tamon Kabata, Ken Yamaji, Takahiro Okawa, Akihiro Sudo, Kenji Ohzono, Yoshiya Tanaka, Yuji Yasunaga, Shuichi Matsuda, Yuuki Imai, Yasuharu Nakashima, goro motomura, Satoshi Ikemura, Ryosuke Yamaguchi, Kazuyuki Karasuyama, Kazuhiko Sonoda, Takashi Nishii, Takashi Sakai, Masaki Takao, Tohru Irie, Tsuyoshi Asano, Norimasa Iwasaki, Tatsuya Atsumi, Satoshi Tamaoki, Ryosuke Nakanishi, Satoe Tanabe, Shunji Kishida, Shigeo Hagiwara, Taisuke Seki, Hiroshi Tsukamoto, Hiroaki Niiro, Yojiro Arinobu, Mitsuteru Akahoshi, Hiroshi Mitoma, Masahiro Ayano, Takeshi Kuroda, Yoshiaki Toyama, Atsushi Funayama, Hironari Hanaoka, Kunihiro Yamaoka, Yasushi Kawaguchi, Hisashi Yamanaka, Tetsuji Hosozawa, Shigeki Momohara, Kentaro Chino, Mikihiro Fujioka, Keichiro Ueshima, Masashi Ishida, Masazumi Saito, Shigeki Hayashi, Akira Ikegami, Toru Ichiseki, Shigekazu Mizokawa, Yoichi Ohta, Yoshitomo Kajino, Fumio Sekiya, Fujio Higuchi, Masahiro Hasegawa, Noriki Miyamoto, Shinichi Miyazaki, Toshio Yamaguchi, Wataru Ando, Kazuyoshi Saito, Kazuhisa Nakano, Yutaka Kuroda, Takuma Yamasaki, Masato Akiyama, Michiaki Kubo, Yoichiro Kamatani, Yukihide Iwamoto, Shiro Ikegawa, Genome-wide Association Study of Idiopathic Osteonecrosis of the Femoral Head, Scientific reports, 10.1038/s41598-017-14778-y, 7, 1, 2017.12, Idiopathic osteonecrosis of the femoral head (IONFH) is an ischemic disorder that causes bone necrosis of the femoral head, resulting in hip joint dysfunction. IONFH is a polygenic disease and steroid and alcohol have already known to increase its risk; however, the mechanism of IONFH remains to be elucidated. We performed a genome-wide association study using ~60,000 subjects and found two novel loci on chromosome 20q12 and 12q24. Big data analyses identified LINC01370 as a candidate susceptibility gene in the 20q12 locus. Stratified analysis by IONFH risk factors suggested that the 12q24 locus was associated with IONFH through drinking capacity. Our findings would shed new light on pathophysiology of IONFH..
17. Sonoda, K.; Motomura, G.; Ikemura, S.; Kubo, Y.; Yamamoto, T.; Nakashima, Y., Effects of intertrochanteric osteotomy plane and preoperative femoral anteversion on the postoperative morphology of the proximal femur in transtrochanteric anterior rotational osteotomy: 3D CT-based simulation study, ORTHOPAEDICS & TRAUMATOLOGY-SURGERY & RESEARCH, 10.1016/j.otsr.2017.06.012, 103, 7, 1005-1010, 2017.11.
18. Utsunomiya, Takeshi; Motomura, Goro; Ikemura, Satoshi; Hamai, Satoshi; Fukushi, Jun-ichi; Nakashima, Yasuharu, The Results of Total Hip Arthroplasty After Sugioka Transtrochanteric Anterior Rotational Osteotomy for Osteonecrosis, JOURNAL OF ARTHROPLASTY, 10.1016/j.arth.2017.04.034, 32, 9, 2768-2773, 2017.09.
19. Daisuke Hara, Satoshi Hamai, Jun-Ichi Fukushi, Kenichi Kawaguchi, goro motomura, Satoshi Ikemura, Keisuke Komiyama, Yasuharu Nakashima, Does Participation in Sports Affect Osteoarthritic Progression after Periacetabular Osteotomy?, American Journal of Sports Medicine, 10.1177/0363546517707942, 45, 11, 2468-2475, 2017.09, Background: Periacetabular osteotomy (PAO) is an effective treatment for symptomatic acetabular dysplasia. However, whether postoperative participation in sports leads to progression of the Kellgren-Lawrence (KL) grade of osteoarthritis (OA) in these patients is unclear. Purpose: To investigate (1) participation in sports before and after PAO and (2) whether postoperative participation in sports leads to progression of the KL grade. Study Design: Case-control study; Level of evidence, 3. Methods: The authors retrospectively reviewed data on 161 patients (183 hips) who underwent PAO for symptomatic acetabular dysplasia with preoperative KL grade 1 or 2 between 1998 and 2011. The mean age at the time of surgery was 42.0 ± 10.9 years (range, 12-64 years), and the mean follow-up duration was 100 months (range, 13-180 months). Data included participation in sports, the University of California, Los Angeles (UCLA) activity scale score, age at the time of surgery, body mass index, follow-up duration, history of treatment for developmental hip dislocations, Merle d'Aubigné-Postel score, Oxford Hip Score, center-edge angle, and KL grade. Univariate and multivariate analyses were applied to determine which factors were associated with progression to KL grade 3 or 4 after PAO. Results: The number of patients who participated in sports significantly increased from 50 (31.1%) preoperatively to 89 (55.3%) postoperatively. The mean UCLA score significantly increased from 4.7 ± 2.1 preoperatively to 5.5 ± 2.0 postoperatively. The KL grade progressed to grade 3 or 4 in 16 hips, including 4 hips that underwent conversion to total hip arthroplasty. No significant differences were found in postoperative participation in sports (89 hips [53.3%] vs 11 hips [68.8%], respectively; P =.24) and the UCLA score (5.6 ± 2.0 vs 5.1 ± 2.0, respectively; P =.30) between hips with KL grade 1 or 2 and KL grade 3 or 4. A multivariate analysis revealed that no factors, including postoperative participation in sports, were significantly associated with progression to KL grade 3 or 4. Conclusion: Postoperative participation in sports after PAO did not significantly and negatively influence progression of the KL grade at midterm follow-up..
20. Kubo, Yusuke; Motomura, Goro; Ikemura, Satoshi; Sonoda, Kazuhiko; Yamamoto, Takuaki; Nakashima, Yasuharu, Effect of collapse on the deformity of the femoral head-neck junction in osteonecrosis of the femoral head, ARCHIVES OF ORTHOPAEDIC AND TRAUMA SURGERY, 10.1007/s00402-017-2720-0, 137, 7, 933-938, 2017.07.
21. Yamaguchi, Ryosuke; Yamamoto, Takuaki; Motomura, Goro; Ikemura, Satoshi; Iwasaki, Kenyu; Zhao, Garida; Iwamoto, Yukihide, Radiological morphology variances of transient osteoporosis of the hip, JOURNAL OF ORTHOPAEDIC SCIENCE, 10.1016/j.jos.2017.02.009, 22, 4, 687-692, 2017.07.
22. Baba, Shoji; Motomura, Goro; Fukushi, Junichi; Ikemura, Satoshi; Sonoda, Kazuhiko; Kubo, Yusuke; Utsunomiya, Takeshi; Hatanaka, Hiroyuki; Nakashima, Yasuharu, Osteonecrosis of the femoral head associated with pigmented villonodular synovitis, RHEUMATOLOGY INTERNATIONAL, 10.1007/s00296-016-3624-y, 37, 5, 841-845, 2017.05.
23. Yasuharu Nakashima, Masanori Fujii, Yasuo Noguchi, Kenya Suenaga, Takuaki Yamamoto, Jun-Ichi Fukushi, goro motomura, Satoshi Hamai, Daisuke Hara, Yukihide Iwamoto, Arthroscopic validation of radiographic minimum joint space width associated with the subchondral bone exposure in symptomatic hip dysplasia, Modern Rheumatology, 10.1080/14397595.2016.1222663, 27, 3, 524-528, 2017.05, Objective: The purpose of this study was to clarify the minimum joint space width (MJSW) that leads to subchondral bone exposure (SBE) in patients with hip dysplasia. Methods: We included 82 subjects (86 hips) who had hip dysplasia with center-edge angle less than 20° and who underwent periacetabular osteotomy combined with hip arthroscopy. The acetabular and femoral cartilages were divided into three regions: anterosuperior, superior, and posterosuperior; for each region, we analyzed the correlation between the incidence of SBE and the MJSW measured on plain radiographs. The disease stage was defined according to the Kellgren and Lawrence grades (KL grade). Results: SBE was found in 51 hips (59.3%) in total, involved the acetabulum in 49 hips (57.0%), and involved the femoral head in 26 hips (30.2%). SBE was more frequent in the acetabulum, with the highest incidence in the anterosuperior region, followed by the superior region. SBE was present in six hips (22.2%), 17 hips (56.7%), and 28 hips (96.5%), at KL-1, KL-2, and KL-3, respectively. MJSW of hips with SBE was significantly smaller than those without SBE (2.3 vs 4.0 mm, p < 0.001), and the cut-off value for MJSW that led to SBE was 3.7 mm (sensitivity: 0.902, 1–specificity: 0.343). SBE was present in 23.3% in patients with MJSW ≥3.7 mm, whereas 76.7% in those <3.7 mm. Conclusions: Cartilage degeneration is more advanced than would be predicted on plain radiographs. The cut-off value of MJSW for SBE was 3.7 mm in patients with symptomatic hip dysplasia..
24. Kubo, Y.; Motomura, G.; Ikemura, S.; Sonoda, K.; Yamamoto, T.; Nakashima, Y., Factors influencing progressive collapse of the transposed necrotic lesion after transtrochanteric anterior rotational osteotomy for osteonecrosis of the femoral head, ORTHOPAEDICS & TRAUMATOLOGY-SURGERY & RESEARCH, 10.1016/j.otsr.2016.10.019, 103, 2, 217-222, 2017.04.
25. Sonoda, Kazuhiko; Motomura, Goro; Kawanami, Satoshi; Takayama, Yukihisa; Honda, Hiroshi; Yamamoto, Takuaki; Nakashima, Yasuharu, Degeneration of articular cartilage in osteonecrosis of the femoral head begins at the necrotic region after collapse: a preliminary study using T1 rho MRI, SKELETAL RADIOLOGY, 10.1007/s00256-017-2567-z, 46, 4, 463-467, 2017.04.
26. Sonoda K, Motomura G, Ikemura S, Kubo Y, Yamamoto T, Nakashima Y, Favorable Clinical and Radiographic Results of Transtrochanteric Anterior Rotational Osteotomy for Collapsed Subchondral Insufficiency Fracture of the Femoral Head in Young Adults, JBJS Open Access, 10.2106/JBJS.OA.16.00013, 2017.03.
27. Hiroyuki Hatanaka, goro motomura, Satoshi Ikemura, Kazuhiko Sonoda, Yusuke Kubo, Takeshi Utsunomiya, Takuaki Yamamoto, Yasuharu Nakashima, Use of a long distally fixed intramedullary stem to treat a periprosthetic femoral fracture following total hip arthroplasty using a thrust plate hip prosthesis
A case report, International Journal of Surgery Case Reports, 10.1016/j.ijscr.2017.06.010, 37, 65-68, 2017.01, Introduction The thrust plate hip prosthesis (TPP; Zimmer, Winterthur, Switzerland) is a hip prosthesis that is no longer in production. Few reports have focused on periprosthetic fractures following total hip arthroplasty (THA) with the use of a TPP. Presentation of case We report a 57-year-old woman with a periprosthetic femoral fracture 13 years after THA with the use of a TPP. A plain radiograph showed a displaced subtrochanteric fracture of the right femur just below the distal tip of the lateral plate without implant loosening. She underwent revision surgery with a long distally fixed intramedullary stem in conjunction with a plate and cable system. Three months after surgery, bone union was confirmed using radiography and the patient was clinically asymptomatic. Discussion We encountered three major problems while planning surgical treatment, these being, discontinuation of the TPP system, loss of proximal femoral cancellous bone, and difficulties with the type of subtrochanteric fracture. After considering these problems, we planned revision surgery using a long distally fixed intramedullary stem in conjunction with a plate and cable system. Conclusion This case shows that sufficient implant preparation based on precise preoperative planning is necessary to obtain good clinical results for the surgical treatment of periprosthetic femoral fractures following THA with the use of a TPP..
28. Sonoda Kazuhiko, Yamamoto Takuaki, Motomura Goro, Karasuyama Kazauyuki, Kubo Yusuke, Yukihide Iwamoto, Fat-suppressed T2-weighted MRI appearance of subchondral insufficiency fracture of the femoral head, SKELETAL RADIOLOGY, 10.1007/s00256-016-2462-z, 45, 11, 1515-1521, 2016.11.
29. Yasuharu Nakashima, Takuaki Yamamoto, Jun-Ichi Fukushi, goro motomura, Satoshi Hamai, Yusuke Kohno, Yukihide Iwamoto, Transtrochanteric rotational osteotomy for avascular necrosis of the femoral head after unstable slipped capital femoral epiphysis
10-year clinical results, Journal of Orthopaedic Science, 10.1016/j.jos.2016.06.014, 21, 6, 831-835, 2016.11, Background Avascular necrosis of the femoral head (AVN) is the most serious complication after unstable slipped capital femoral epiphysis (SCFE), and is often unsalvageable. We report a minimum 10 years of clinical results for transtrochanteric rotational osteotomy of the femoral head (TRO) for AVN. Methods This study included 7 patients (7 hips) with a mean age at surgery of 13.3 years, and the follow-up period was 15.8 years. All patients had prior treatment via closed reduction and pinning of the unstable SCFE, and showed severely collapsed femoral heads. The direction of rotation was anterior in 3 hips and posterior in 4. The Merle d'Aubigné–Postel score (MDPS) was used for clinical assessment, and joint degeneration was assessed with the Kellgren and Lawrence classification (KL-grade). Results The spherical intact area of the femoral head was moved to the weight-bearing portion, and subluxation was corrected via rotation combined with intentional varus positioning. The mean MDPS improved from 10.3 points to 15.6 points at 5 years, and it was maintained at 15.0 points by 10 years; 3 hips were excellent, 1 was good, 2 were fair, and 1 showed poor outcomes. No patient experienced re-collapse after TRO or required conversion to hip replacement or arthrodesis. After 10 years, degenerative changes became evident over time, and 2 hips progressed to KL-4 with a decreased MDPS. Conclusions Although some joint degeneration is inevitable in the long-term, TRO is an effective salvage procedure for treating AVN after unstable SCFE..
30. Kubo Yusuke, Yamamoto Takuaki, Motomura Goro, Karasuyama Kazuyuki, Sonoda Kazuhiko, Yukihide Iwamoto, Patient-reported outcomes of femoral osteotomy and total hip arthroplasty for osteonecrosis of the femoral head: a prospective case series study, SPRINGERPLUS, 10.1186/s40064-016-3576-4, 5, 2016.10.
31. Takeshi Utsunomiya, Takuaki Yamamoto, goro motomura, Satoshi Hamai, Yukihide Iwamoto, The clinicopathologic findings of a subchondral insufficiency fracture of the femoral head in a male patient
a case report, Skeletal Radiology, 10.1007/s00256-016-2443-2, 45, 10, 1425-1429, 2016.10, There are few reports describing the clinicopathologic characteristics of subchondral insufficiency fractures of the femoral head (SIF) in men over 50 years of age. A 59-year-old man experienced a sudden onset of the left hip pain without any antecedent trauma. The hip pain did not improve despite conservative treatments, and he underwent a total hip arthroplasty. The mid-coronal cut section of the resected femoral head revealed a fracture line paralleling the subchondral bone endplate beneath the articular cartilage. In addition, the subchondral fracture broadly underlaid the weight bearing area of the femoral head. Histopathologically, reparative tissue including fracture callus and granulation tissue, as well as thin disconnected bone trabeculae were observed. These clinicopathological findings were similar to those of previously described SIF in women. It is therefore important to consider SIF in cases of acute hip pain, even in middle-aged men..
32. Masanobu Ohishi, Yasuharu Nakashima, Takuaki Yamamoto, goro motomura, Jun-Ichi Fukushi, Satoshi Hamai, Yusuke Kohno, Yukihide Iwamoto, Cementless total hip arthroplasty for patients previously treated with femoral osteotomy for hip dysplasia
the incidence of periprosthetic fracture, International Orthopaedics, 10.1007/s00264-015-2992-3, 40, 8, 1601-1606, 2016.08, Purpose: Femur deformities can make stem fixation difficult in total hip arthroplasty (THA). We report the clinical results of cementless THA using a press-fit stem in patients who had previously undergone femoral osteotomy for hip dysplasia. Methods: The subjects included 66 hips in 64 patients, with the mean follow-up period of 7.3 years. THA was performed at a mean period of 17.1 years after intertrochanteric femoral osteotomy. Valgus osteotomy was performed in 42 hips, and varus osteotomy in 24. Clinical results were evaluated by using the Merle d’Aubigne-Postel score. Implant survival was determined with revision as the end point, and any related complications were investigated. Results: The Merle d’Aubigne-Postel score improved from 9.4 to 16.1 at the final follow-up, without any implant loosening. However, periprosthetic femoral fractures were observed in four hips (6.0 %), one intra-operatively and three within three weeks after THA. Among these cases, three hips previously had varus osteotomy (12.5 %) and one hip had valgus osteotomy (2.3 %). Two hips were revised with full porous stems and circumferential wiring. The five and ten year cumulative survivorship rates were 97 % (range, 88.8–99.3 %) and 97 % (88.8–99.3 %), respectively. Conclusions: Although the use of a press-fit cementless stem yielded acceptable results in most of the patients, perioperative femoral fracture was a major complication especially in the patients previously treated with intertrochanteric varus osteotomy. Careful planning and implant selection could be emphasized for these cases..
33. Kensei Yoshimoto, Yasuharu Nakashima, Takuaki Yamamoto, Jun-Ichi Fukushi, goro motomura, Masanobu Ohishi, Satoshi Hamai, Yukihide Iwamoto, Dislocation and its recurrence after revision total hip arthroplasty, International Orthopaedics, 10.1007/s00264-015-3020-3, 40, 8, 1625-1630, 2016.08, Purpose: Dislocation is a leading cause of failure after revision total hip arthroplasty (THA). This study was conducted to examine the risk factors for dislocation as well as their recurrence after revision THA. Methods: We retrospectively reviewed 178 revision THAs in 162 patients between 1998 and 2013. The mean patient age was 65.2 years at operation and the mean follow-up period was 6.7 years. Multivariate logistic regression was performed to identify risk factors for dislocation, and further comparison was made between patients with single and recurrent dislocations. Results: Sixteen hips in 15 patients (9.0 %) dislocated at a mean of 9.1 months (range, 0–83 months) after revision THA. Multivariate analysis identified advanced age (odds ratio [OR] = 2.94/10 years) and osteonecrosis of the femoral head (OR = 7.71) as the independent risk factors for any dislocations. Risk factors for recurrent dislocations, which were observed in eight hips (50 %), were later dislocations (≥4 months) and lower BMI. Conclusion: Dislocation is a serious problem after revision THA with multiple risk factors. Although our findings were limited to revision THAs done through posterolateral approach, recognition of these factors is helpful in patient education and surgical planning..
34. Masanori Fujii, Yasuharu Nakashima, Yasuo Noguchi, Takuaki Yamamoto, goro motomura, Satoshi Hamai, Yukihide Iwamoto, Factors Associated With Severity of Intra-articular Lesions in Patients With Severe Hip Dysplasia, Arthroscopy - Journal of Arthroscopic and Related Surgery, 10.1016/j.arthro.2016.01.060, 32, 8, 1581-1589, 2016.08, Purpose To identify demographic and morphologic factors associated with the severity of intra-articular lesions in patients with severe hip dysplasia. Methods One hundred twenty-one patients (134 hips) with symptomatic hip dysplasia were retrospectively reviewed. The cartilage and labral lesions were scored according to the Outerbridge and the original classification systems, respectively. The association of the cartilage and labrum scores with patient demographics (age, gender, body mass index, bilateral hip dysplasia, and treatment history for developmental hip dislocation) and morphologic factors (the lateral center-edge angle, Sharp angle, acetabular index, acetabular head index, acetabular depth ratio, Shenton line disruption, roundness index of the femoral head, and femoral neck shaft angle) were determined using a multiple linear regression analysis. Results The cartilage and labral scores were significantly associated with radiographic osteoarthritis; however, these scores showed wide distribution among hips with equivalent degrees of radiographic osteoarthritis. Age (38.4 ± 12.8 years) (P <.001), lateral center-edge angle (0.2 ± 9.0°) (P =.014), acetabular head index (54.4 ± 9.1%) (P =.001), and the roundness index of the femoral head (55.6 ± 4.6%) (P =.022) were identified as independent factors associated with the cartilage score. Age (P <.001), having a medical history of developmental hip dislocation (P =.002), acetabular index (27.8 ± 6.8°) (P =.011), and the roundness index of the femoral head (P =.022) were identified as independent factors associated with the labral score. Conclusions Our findings suggest that the morphologic factors responsible for severe intra-articular lesions differ for cartilage degeneration and labral tears in patients with severe hip dysplasia. Decreased acetabular coverage of the femoral head was responsible for cartilage degeneration severity, whereas an increased acetabular index was responsible for labral tear severity. Level of Evidence Level III, diagnostic study..
35. Satoshi Hamai, Yasuharu Nakashima, Naohiko Mashima, Takuaki Yamamoto, Tomomi Kamada, goro motomura, Hiroshi Imai, Jun-Ichi Fukushi, Hiromasa Miura, Yukihide Iwamoto, Comparison of 10-year clinical wear of annealed and remelted highly cross-linked polyethylene
A propensity-matched cohort study, Journal of the Mechanical Behavior of Biomedical Materials, 10.1016/j.jmbbm.2015.12.022, 59, 99-107, 2016.06, No previous studies comparing the clinical wear rates of the two different kinds of cross-linked ultra-high-molecular-weight polyethylene (XLPE), annealed and remelted, are available. We compared the creep and steady wear rates of 36 matched pairs (72 hips in total) adjusting for baseline characteristics with propensity score matching techniques. Zirconia femoral heads with 26-mm diameter were used in all cases. The femoral-head cup penetration was measured digitally on radiographs. Significantly greater creep ( p=0.006) was detected in the remelted (0.234 mm) than annealed (0.159 mm) XLPE. However, no significant difference ( p=0.19) was found between the steady wear rates (0.003 and 0.008 mm/year, respectively) of the annealed and remelted XLPE. Multiple regression analyses showed that remelted XLPE is significant independent variable ( p<0.001) that is positively associated with creep. However, the patient age and body weight, cup size, the liner thickness, cup inclination, follow-up periods, and postoperative Merle d'Aubigné hip score had no significant effects ( p>0.05) on the steady wear rates. No patients exhibited above the osteolysis threshold of 0.1 mm/year, progressive radiolucencies, osteolysis, or polyethylene fracture. This[U+3000]propensity-matched cohort study document no significant difference in wear resistant performances of annealed and remelted XLPE over an average period of 10 years..
36. Taishi Sato, Yasuharu Nakashima, Keisuke Komiyama, Takuaki Yamamoto, goro motomura, Yukihide Iwamoto, The Absence of Hydroxyapatite Coating on Cementless Acetabular Components Does Not Affect Long-Term Survivorship in Total Hip Arthroplasty, Journal of Arthroplasty, 10.1016/j.arth.2015.11.034, 31, 6, 1228-1232, 2016.06, Background: Hydroxyapatite (HA) has been applied to joint prostheses as a bioactive coating to prolong their durability. However, HA benefits for cup survival in total hip arthroplasty (THA) remain controversial. In this study, we compared the survival of cups with and without HA coating during a minimum follow-up of 18 years. Methods: In total, 183 THA cases in 163 patients were analyzed, including 73 cups with HA coating (HA+ group) and 110 without HA coating (HA- group); otherwise, the cups had identical titanium-sprayed rough surfaces and were fixed with screws. In both groups, the same conventional polyethylene liners were applied. Zirconia and alumina ceramic heads were used in the HA+ and HA- groups, respectively. We retrospectively analyzed cup survival based on cup revision for any reason or aseptic loosening as end points. Results: In total, 7 and 8 revisions were performed in the HA- and HA+ groups with survival rates of 86.3% and 90.1%, respectively. Among them, 3 cups in the HA- group and 1 cup in the HA+ group were revised for aseptic loosening in 20 years (survival rates 94.1% and 98.7%, respectively). No significant difference was detected in cup survival rates between the groups based on both end points. There were no stem revisions during the observation period. Conclusion: The results suggested that HA coating did not have either beneficial or adverse effects on the long-term cup survival in primary cementless THA..
37. Hiroyuki Hatanaka, Takuaki Yamamoto, goro motomura, Kazuhiko Sonoda, Yukihide Iwamoto, Histopathologic findings of spontaneous osteonecrosis of the knee at an early stage
a case report, Skeletal Radiology, 10.1007/s00256-016-2328-4, 45, 5, 713-716, 2016.05, We histopathologically examined a surgically resected full specimen obtained from an early-stage spontaneous osteonecrosis of the knee (SPONK). On a mid-coronal cut section of the resected medial femoral condyle, a linear fracture line paralleling the subchondral bone endplate was found. Histopathologically, prominent callus formation was seen comprising of reactive woven bone and granulation tissue on both sides of the fracture. Fracture-related bone debris was focally observed at the osteochondral side of the fracture. Definitive features of antecedent bone infarction such as creeping substitution and bone marrow necrosis were not detected. These findings suggested that SPONK was the result of a subchondral fracture rather than primary osteonecrosis..
38. Masayuki Kanazawa, Yasuharu Nakashima, Masanobu Ohishi, Satoshi Hamai, goro motomura, Takuaki Yamamoto, Jun-Ichi Fukushi, Takahiro Ushijima, Daisuke Hara, Yukihide Iwamoto, Pelvic tilt and movement during total hip arthroplasty in the lateral decubitus position, Modern Rheumatology, 10.3109/14397595.2015.1092914, 26, 3, 435-440, 2016.05, Objectives: Total hip arthroplasty (THA) is often performed in the lateral decubitus (lateral) position. In this position, the pelvis may have various degrees of tilt leading to implant malposition. We sought to quantify the pelvic tilt in lateral position and further pelvic movement during surgery.Methods: In 95 cases with primary THA, three-dimensional pelvic tilts were quantified by superimposing images reconstructed from CT data onto antero-posterior radiographs taken in lateral position at set-up and after cup placement. Pelvises were fixed with a device compressing anterior superior iliac spines and sacrum.Results: Various degrees of pelvic tilt occurred compared to the supine position; sagittal: -3.1° (-25.5° to 10.2°), axial: 3.9° (-8.4° to 17°), coronal: 0.9° (-11.9° to 13.2°). Absolute changes more than 5° were observed 43%, 47%, and 12% in the sagittal, axial, and coronal planes, respectively. The more preoperative posterior pelvic tilt resulted in the more change in the sagittal plane. Further pelvic movement of about 3° in three planes were observed ranging from -11° to 20° after cup placement.Conclusion: This study showed various pelvic tilt and movement during THA. As pelvic tilt directly alters the cup orientation, its changes should be well understood. Improved tools for positioning and holding the pelvis are required..
39. T. Yamamoto, goro motomura, K. Karasuyama, Yasuharu Nakashima, Toshio Doi, Y. Iwamoto, Results of the Sugioka transtrochanteric rotational osteotomy for osteonecrosis
Frequency and role of a defect of the quadratus femoris muscle in osteonecrosis progression, Orthopaedics and Traumatology: Surgery and Research, 10.1016/j.otsr.2016.01.017, 102, 3, 387-390, 2016.05, Background: During transtrochanteric rotational osteotomy (RO), it is important to preserve the posterior column artery (PCA), which is generally located in the adipose tissue underneath the quadratus femoris muscle (QF). If there is a defect in the QF, the risk of injuring the PCA, subsequently resulting in total necrosis of the femoral head, may increase. Therefore, we investigated: (1) the frequency of defects of the QF at the time of RO, and (2) clinical outcome of RO based upon a defect of the QF. Hypothesis: The presence of defects of the QF at the time of RO could be detected pre-operatively by magnetic resonance imaging. Methods: RO was performed in 124 hips between 2001 and 2010. In all, 95 of the hips were in male patients and 29 in female patients. The mean age was 45.4 years (range: 11-61 years) at the time of surgery and MRI was performed before RO in all cases. We retrospectively evaluated the progression of a collapse through 3 years after RO. Results: MRI showed a defect in the QF in four hips (3.2%) (2 males, 2 females), all of which were confirmed intra-operatively. Among the four patients, one (25%) underwent total hip arthroplasty because of varus deformity of the osteotomy site due to total necrosis of the femoral head 1 year after RO. The 120 hips with a normal QF showed no evidence of total necrosis or progression of necrosis of the femoral head, indicating that the presence of defects of the QF may increase the risk of poor survivorship of this procedure. Conclusions: Defects of the QF have been reported to occur in 1-2% of all patients, whereas in our study the incidence in ON was approximately 3%. In ON patients with QF defects, pre-operative MRI evaluation of the QF appears to be important when planning RO, followed by a carefully performed surgical procedure. Level of evidence: IV; retrospective case series without control group..
40. Jun-Ichi Fukushi, Shoji Tokunaga, Yasuharu Nakashima, goro motomura, Chikage Mitoma, Uchi Hiroshi, Masutaka Furue, Yukihide Iwamoto, Effects of dioxin-related compounds on bone mineral density in patients affected by the Yusho incident, Chemosphere, 10.1016/j.chemosphere.2015.11.091, 145, 25-33, 2016.02, Exposure to dioxin-related compounds results in many adverse health effects. Several studies have examined the effects of dioxin-related compounds on human bone metabolism with inconsistent results. In Japan in 1968, accidental human exposure to rice oil contaminated with dioxin-related compounds led to the development of Yusho oil disease. The aim of this study was to determine whether exposure to dioxin-related compounds was associated with bone mineral density in Yusho patients. In 2010, 262 women and 227 men underwent dual-energy X-ray absorptiometry bone scans as part of the nationwide Yusho health examination. Serum levels of polychlorinated dibenzo-p-dioxin, polychlorinated dibenzofurans, and non-ortho polychlorinated biphenyls were measured using high-resolution gas chromatography and high-resolution mass spectrometry. When adjusted for prefecture, 1,2,3,4,7,8-HxCDD and 2,3,7,8-TCDF were significantly positively associated with Z-scores in men. No congeners were positively associated with Z-scores in women. After adjustment for prefecture and body mass index, one congener, 1,2,3,4,6,7,8-HpCDD, was negatively associated with Z-scores in women. In contrast, no congeners remained significant in men after adjusting for body mass index. This may suggest that 1,2,3,4,6,7,8-HpCDD has a negative effect on bone mineral density in women; however, the findings should be interpreted carefully, because no increase in the serum level of this congener was observed in patients with Yusho disease..
41. Kenyu Iwasaki, Takuaki Yamamoto, goro motomura, Kazuyuki Karasuyama, Kazuhiko Sonoda, Yusuke Kubo, Yukihide Iwamoto, Common site of subchondral insufficiency fractures of the femoral head based on three-dimensional magnetic resonance imaging, Skeletal Radiology, 10.1007/s00256-015-2258-6, 45, 1, 105-113, 2016.01, Objectives: The objective of this study was to investigate the common sites of subchondral insufficiency fractures of the femoral head (SIF) based on three-dimensional (3-D) reconstruction of MR images. Materials and methods: In 33 hips of 31 consecutive patients diagnosed with SIF, 3-D reconstruction of the bone, fracture, and acetabular edge was performed using MR images. These 3-D images were used to measure the fractured areas and clarify the positional relationship between the fracture and degree of acetabular coverage. Results: The fractured area in the anterior portion was significantly larger than in the posterior area. In 11 cases, the fractures contacted the acetabular edge and were distributed on the lateral portion. The indices of acetabular coverage (center-edge angle and acetabular head index) in these cases were less than the normal range. In the remaining 22 cases, the fractures were apart from the acetabular edge and distributed on the mediolateral centerline of the femoral head. The majority of these cases had normal acetabular coverage. Conclusions: The common site of SIF is the anterior portion. In addition, two types of SIF are proposed: (1) Lateral type: the contact stress between the acetabular edge and lateral portion of the femoral head causes SIF based on the insufficient acetabular coverage, and (2) Central type: the contact stress between the acetabular surface and the mediolateral center of the femoral head causes SIF independent from the insufficiency of acetabular coverage. These findings may be useful for considering the treatment and prevention of SIF..
42. Hiroki Kobayashi, Yasuharu Nakashima, Takuaki Yamamoto, goro motomura, Masayuki Kanazawa, Kenji Takagishi, Yukihide Iwamoto, Late Anterior Dislocation Due to Posterior Pelvic Tilt in Total Hip Arthroplasty, The open orthopaedics journal, 10.2174/1874325001610010206, 10, 206-212, 2016.01, BACKGROUND: Excessive pelvic tilt may be one of the factors leading to instability in total hip arthroplasty (THA), even when the acetabular cup is placed properly. To our knowledge, only a few studies have described late anterior dislocation due to posterior pelvic tilt. We present 3 cases with late anterior dislocations possibly due to posterior pelvic tilt.
CASES PRESENTATIONS: Case-1: An 84-years-old woman fell and presented with an anterior dislocation 12-years after THA. Her pelvis had tilted to approximately 30° posteriorly in a supine position. After conservative treatment, she presented with 10 recurrent anterior dislocations. She had thoracolumbar kyphosis due to multiple compression fractures. Revision with anterior placement of an elevated liner and a 32-mm head corrected the dislocation, and no further dislocations occurred. Case-2: A 78-years-old woman fell and presented with an anterior dislocation 4-years after THA. Her posterior pelvic tilt had increased 23° due to a lumbar compression fracture. Revision by decreasing the cup anteversion was performed, but recurrent posterior dislocations occurred. Owing to her worsened general condition, further treatment was abandoned. Case-3: A 79-years-old woman twisted her body and presented an anterior dislocation 3-years after THA. After manual reduction and conservative treatment, the dislocation recurred. Her posterior pelvic tilt had increased 16°.
CONCLUSION: Although minor trauma triggered the anterior instability in these patients, the underlying pathomechanism existed in the progressive pelvic posterior tilt due to thoracolumbar kyphosis. As longer life expectancy as well as implant survivorship is predicted, attention must be paid to the change of pelvic tilt in elderly patients..
43. Takeshi Utsunomiya, Takuaki Yamamoto, goro motomura, Kazuyuki Karasuyama, Kazuhiko Sonoda, Yusuke Kubo, Hiroyuki Hatanaka, Yukihide Iwamoto, The choice of locking plate in the treatment of peri-implant femoral fracture eight years after trans-trochanteric rotational osteotomy
A case report, International Journal of Surgery Case Reports, 10.1016/j.ijscr.2016.07.020, 26, 101-103, 2016.01, Introduction Transtrochanteric anterior rotational osteotomy of the femoral head (TRO) was developed as a joint preserving surgery for osteonecrosis of the femoral head. To the best of our knowledge, peri-implant fractures after femoral osteotomy have rarely been reported. Presentation of case We report a 58-year-old female who suffered a peri-implant femoral shaft fracture following a fall from a stepladder eight years after TRO. Fracture union was achieved six months after a preferred proximal femoral locking plate. Discussion The entry point of the ante-grade femoral nail would have been very close to the new position of the nutrient artery of the femoral head occasioned by the TRO and to avoid injury, we chose proximal femoral locking plate. Conclusion It is important to consider the new position of the nutrient artery of the femoral head in the surgical planning of peri-implant fracture after TRO..
44. Yusuke Kubo, Takuaki Yamamoto, goro motomura, Satoshi Kido, Kazuyuki Karasuyama, Kazuhiko Sonoda, Yukihide Iwamoto, Transient epiphyseal lesion of the femoral head after traumatic hip dislocation
A case report, International Journal of Surgery Case Reports, 10.1016/j.ijscr.2016.05.009, 24, 46-49, 2016.01, Introduction We experienced a rare case in which magnetic resonance imaging (MRI) showed a transient epiphyseal lesion of the femoral head four months after traumatic hip dislocation. To our knowledge, there have been no previously published reports on the development of such transient lesions after traumatic hip dislocation involving no abnormalities just after dislocation. Presentation of case We report a 22-year-old man who showed a transient epiphyseal lesion of the femoral head after traumatic hip dislocation. On MRI performed two days after dislocation, no bony injuries were observed around the hip joint. Four months after dislocation, the patient suddenly experienced right hip pain without any new trauma or injury. A low-intensity band convex to the articular surface was apparent above the epiphyseal scar on T1-weighted imaging, and bone marrow edema was observed around the band lesion on short-tau inversion recovery imaging. Following a two-month period of non-surgical conservative therapy, the patient's hip pain resolved and the low-intensity band was no longer observed on follow-up MRI. Discussion Although the detailed pathogenesis of this transient changes was unclear, we speculate that prolonged rest after traumatic hip dislocation may contribute to bone insufficiency, resulting in an insufficiency fracture of the femoral head. Conclusion This study suggests that transient epiphyseal lesions of the femoral head may occur in patients with a history of traumatic hip dislocation associated with an adapted long-term rest..
45. Kazuhiko Sonoda, Takuaki Yamamoto, goro motomura, Satoshi Hamai, Kazuyuki Karasuyama, Yusuke Kubo, Yukihide Iwamoto, Bilateral corticosteroid-induced osteonecrosis of the femoral head detected at a 6-week interval, SpringerPlus, 10.1186/s40064-015-1458-9, 4, 1, 1-4, 2015.12, Introduction: Corticosteroid-induced osteonecrosis of the femoral head (ONFH) often affects both femoral heads. Such bilateral ONFH cases are generally detected concurrently on magnetic resonance imaging (MRI). On the other hand, in unilateral cases, it is rare that contralateral ONFH is subsequently detected. We herein report a case in which bilateral ONFH was detected in both femoral heads by repeated MRI examination at an interval of 6 weeks. Case description: A 34-year-old man with purpura nephritis was started on corticosteroid therapy with prednisolone at 30 mg/day. Eight months after the initiation of corticosteroid therapy, he complained of left hip pain with no antecedent triggering activity. MRI obtained 8.5 months after the initiation of corticosteroid therapy showed the findings of osteonecrosis of the left femoral head, while no abnormalities were detected in the right femoral head. On the second MRI obtained 10 months after the initiation of corticosteroid treatment, however, osteonecrosis of the right femoral head was newly detected without an increase of the corticosteroid dose. Conclusions: This case may indicate that corticosteroid-induced bilateral ONFH do not always develop at the same time..
46. Kazuyuki Karasuyama, Takuaki Yamamoto, goro motomura, Kazuhiko Sonoda, Yusuke Kubo, Yukihide Iwamoto, The role of sclerotic changes in the starting mechanisms of collapse
A histomorphometric and FEM study on the femoral head of osteonecrosis, Bone, 10.1016/j.bone.2015.09.009, 81, 644-648, 2015.12, Purpose: To assess the distributions of stress, strain, and fractured areas using a finite element model (FEM), and examine the osteoclastic activity histopathologically in osteonecrosis of the femoral head. Methods: Three femoral heads were obtained during hip arthroplasty for femoral head osteonecrosis. One sample with a normal area, two samples with a non-sclerotic boundary without collapse (Type 1), two samples with a non-collapsed sclerotic boundary (Type 2), and two samples with a collapsed sclerotic boundary (Type 3) were collected from each femoral head for the FEM and histopathological analyses. FEM was performed using CT data, and the distributions of von Mises equivalent stress, octahedral shear stress, octahedral shear strain, and simulated fractured area were evaluated. Furthermore, the osteoclast count at the boundary was compared for each type. Results: In normal and Type 1 samples, the distributions of von Mises equivalent stress, octahedral shear stress, octahedral shear strain, and the fractured area were equally concentrated along the whole analytical range; however, in the Type 2 and 3 samples, they were concentrated along the thickened bone trabeculae at the boundary, which corresponded to the fractured area. Histopathologically, a significantly increased osteoclast number was observed only at the collapsed sclerotic boundary. Conclusion: These results demonstrated that both shear stress and shear strain tend to be concentrated on thickened bone trabeculae at the boundary. Fracture analyses revealed that the boundary of sclerotic changes, which results from the repair process, may be the starting point of the fracture. Additionally, the osteoclastic activity increases after collapse..
47. Yusuke Kubo, Takuaki Yamamoto, goro motomura, Nobuaki Tsukamoto, Kazuyuki Karasuyama, Kazuhiko Sonoda, Hiroyuki Hatanaka, Takeshi Utsunomiya, Yukihide Iwamoto, MRI-detected bone marrow changes within 3 weeks after initiation of high-dose corticosteroid therapy
a possible change preceding the subsequent appearance of low-intensity band in femoral head osteonecrosis, Rheumatology International, 10.1007/s00296-015-3346-6, 35, 11, 1909-1912, 2015.11, Osteonecrosis of the femoral head is considered to occur early during the course of corticosteroid treatment. However, it remains unclear exactly how early it can develop after initiation of corticosteroid treatment. We report a case of osteonecrosis of the femoral head in which abnormal findings were observed on short-tau inversion recovery (STIR) sequence image performed 2 weeks and 4 days after initiation of high-dose corticosteroid therapy. A 45-year-old man with hemophagocytic syndrome was started on prednisolone, with a maximum dose of 40 mg/day. On day 13 after initiation of this corticosteroid therapy, he transiently experienced left hip pain with no apparent cause. STIR sequence image 5 days after the onset of pain revealed high-intensity bone marrow lesions at the femoral neck of both hips. At 3 months after initiation of corticosteroid therapy, T1-weighted magnetic resonance imaging revealed concave-shaped low-intensity bands, which corresponded to the preceding high-intensity lesions on both hips. Because of the subsequent progression to collapse of the left femoral head, he underwent prosthetic replacement surgery. The high-intensity lesions on STIR sequence image indicate the possibility that osteonecrosis can occur within 3 weeks after initiation of high-dose corticosteroid therapy..
48. Yongseung Lee, Motomura Goro, Takuaki Yamamoto, Yasuharu Nakashima, Masanobu Ohishi, Iura Kunio, Yukihide Iwamoto, Rapidly destructive arthrosis of the hip joint in a young adult with systemic lupus erythematosus, Rheumatology International, 10.1007/s00296-015-3304-3., 35, 10, 1753-1757, 2015.10.
49. Yongseung Lee, goro motomura, Takuaki Yamamoto, Yasuharu Nakashima, Masanobu Ohishi, Satoshi Hamai, Kunio Iura, Yukihide Iwamoto, Rapidly destructive arthrosis of the hip joint in a young adult with systemic lupus erythematosus, Rheumatology International, 10.1007/s00296-015-3304-3, 35, 10, 1753-1757, 2015.10, A 37-year-old female had been treated with corticosteroids for systemic lupus erythematosus clinically diagnosed at age 10. She suddenly had right hip pain without any antecedent trauma. Four months after the onset of pain, she visited her primary care physician. On magnetic resonance imaging, joint space narrowing at the weight-bearing area was already seen with bone marrow edematous lesions in both the femoral head and acetabulum. She was treated non-operatively; however, her pain continued to worsen in severity. Thirteen months after the onset of pain, she was referred to our hospital. A plain radiograph showed subluxation of the collapsed femoral head accompanied by destruction of the acetabular rim. Because of her severe intractable pain, she underwent total hip arthroplasty 1 month after her first visit. Histological examination of the resected femoral head revealed pseudogranulomatous lesions along with prominent callus formation, suggesting rapid destruction of the femoral head..
50. Motomura Goro, Takuaki Yamamoto, 烏山和之, Yukihide Iwamoto, Bone SPECT/CT of femoral head subchondral insufficiency fracture, Clinical Nuclear Medicine, 10.1097/RLU.0000000000000886, 40, 9, 752-754, 2015.09.
51. Kazuhiko Sonoda, Takuaki Yamamoto, goro motomura, Yasuharu Nakashima, Ryosuke Yamaguchi, Yukihide Iwamoto, Outcome of transtrochanteric rotational osteotomy for posttraumatic osteonecrosis of the femoral head with a mean follow-up of 12.3 years, Archives of Orthopaedic and Trauma Surgery, 10.1007/s00402-015-2282-y, 135, 9, 1257-1263, 2015.09, Introduction: This study examined the outcomes of applying transtrochanteric rotational osteotomy (TRO) for posttraumatic osteonecrosis of the femoral head (ON). Patients and Methods: We retrospectively reviewed 28 hips in 28 patients (male, n = 17; female n = 11) with a mean age of 34.8 years (12–61 years) at the time of TRO. Transtrochanteric anterior rotational osteotomy (ARO) was used when the lesion was localized on the anterior aspect of the femoral head, and transtrochanteric posterior rotational osteotomy (PRO) was indicated in patients with lesions limited to the posterior aspect of the femoral head. The mean follow-up period was 12.3 years (5.0–21.3 years). We investigated the patients’ clinical and radiological factors, including age, sex, body mass index, preoperative Harris Hip Score (HHS), type of antecedent trauma, preoperative stage, and postoperative intact ratio (the ratio of the intact articular surface of the femoral head to the weight-bearing surface of the acetabulum). We divided the patients into a hip-survival group and a conversion-to-total hip arthroplasty (THA) group and then compared these factors between the two groups. Results: At the final follow-up, 22 hips had survived with a mean HHS of 85.8. The remaining six hips underwent THA at a mean of 10.2 years after TRO. The preoperative stage was correlated with hip survival. Furthermore, the postoperative intact ratio was significantly lower in the conversion-to-THA group. Based on the receiver operating characteristic curve, a ratio of less than 33.6 % was found to be associated with the need to convert to THA. Conclusions: TRO to correct posttraumatic ON resulted in favorable midterm results. The possible risk factors for conversion to THA were an advanced preoperative stage and a postoperative intact ratio of less than 33.6 %..
52. Kazuhiko Sonoda, Takuaki Yamamoto, goro motomura, Ryosuke Yamaguchi, Kazuyuki Karasuyama, Yukihide Iwamoto, Contralateral osteonecrosis of the femoral head newly developed after increasing the dose of corticosteroids, Journal of Orthopaedic Science, 10.1007/s00776-014-0541-3, 20, 4, 772-775, 2015.07.
53. , Shinji Takahashi, Wakaba Fukushima, Takuaki Yamamoto, Yukihide Iwamoto, Toshikazu Kubo, Nobuhiko Sugano, Yoshio Hirota, Takeo Matsuno, Hiroshi Ito, Shunji Kishida, Junichi Nakamura, Yoshihide Nakamura, Masaki Kishiya, Yuji Yasunaga, Takuma Yamasaki, Daisuke Takahashi, Tsuyoshi Asano, Tokifumi Majima, Setsuro Komiya, Yasuhiro Ishidou, Yoshiya Arishima, Tamon Kabata, Tadami Matsumoto, Ayumi Kaneuji, Kenji Ohzono, Moritoshi Itoman, Takayuki Nishiyama, Takaaki Fujishiro, Fujio Higuchi, Takahiro Okawa, Mikihiro Fujioka, Keiichiro Ueshima, goro motomura, Akihiro Sudo, Etsuo Chosa, Makoto Osaki, Yukiharu Hasegawa, Naoto Endo, Kunihiko Tokunaga, Nobuhiro Kaku, Takashi Nishii, Takashi Sakai, Masaki Takao, Kunio Takaoka, Hiroaki Nakamura, Hiroyoshi Iwaki, Hidenobu Miki, Takao Hotokebuchi, Masaaki Mawatari, Setsuo Ninomiya, Temporal trends in characteristics of newly diagnosed nontraumatic osteonecrosis of the femoral head from 1997 to 2011
A hospital-based sentinel monitoring system in Japan, Journal of epidemiology, 10.2188/jea.JE20140162, 25, 6, 437-444, 2015.01, Background: Nontraumatic osteonecrosis of the femoral head (ONFH) is a rare disorder caused by ischemic necrosis of unknown etiology. A few studies have demonstrated trends in the number of patients with ONFH. However, there are no data on temporal trends in characteristics such as age, gender, and causative factors. To investigate this, we examined data from a multicenter hospital-based sentinel monitoring system in Japan. Methods: A total of 3041 newly-diagnosed ONFH patients from 34 participating hospitals who were reported to the system from 1997-2011 were analyzed. We examined age at diagnosis, potential causative factors, and underlying diseases for which patients received systemic steroid administration. Their temporal trends were assessed according to date of diagnosis in 5-year intervals (1997-2001, 2002-2006, and 2007-2011). Results: The gender ratio and distribution of potential causative factors did not change. Regarding underlying diseases requiring steroid administration, the proportion of patients with systemic lupus erythematosus decreased in males (10% to 6.4%) and in females (37% to 29%). Proportion of patients with renal transplantation fell consistently across the study period in both males (3.8% to 1.2%) and females (3.2% to 0.8%). In contrast, the proportion of patients receiving steroids for pulmonary disease (except asthma) significantly increased in both males (0.5% to 5.5%) and females (0.5% to 3.6%). Conclusions: This large descriptive study is the first to investigate temporal trends in the characteristics of ONFH, which provide useful information for future studies..
54. Ryosuke Yamaguchi, Takuaki Yamamoto, goro motomura, Satoshi Ikemura, Kenyu Iwasaki, Garida Zhao, Toshio Doi, Yukihide Iwamoto, Bone and cartilage metabolism markers in synovial fluid of the hip joint with secondary osteoarthritis, Rheumatology (Oxford, England), 10.1093/rheumatology/keu253, 53, 12, 2191-2195, 2014.12, OBJECTIVE: The aim of this study was to compare the levels of bone and cartilage metabolism markers in the synovial fluid of the hip joint between patients with secondary OA due to osteonecrosis of the femoral head (ONFH), rapidly destructive arthrosis (RDA) and developmental dysplasia of the hip (DDH).
METHODS: We studied 70 synovial fluid samples obtained from 57 patients with ONFH (mean age 46 years, 34 males, 23 females), 21 samples obtained from 21 patients with RDA (mean age 70 years, 2 males, 19 females) and 20 samples obtained from 20 patients with DDH (mean age 56 years, 2 males, 18 females). The levels of bone alkaline phosphatase (BAP) and tartrate-resistant acid phosphatase 5b (TRACP-5b), as bone metabolism markers, and matrix metalloproteinase 3 (MMP-3) and keratan sulphate (KS), as cartilage metabolism markers, were analysed.
RESULTS: The levels of BAP, MMP-3 and KS were significantly higher in the ONFH group than in the RDA and DDH groups. The levels of TRACP-5b were highest in the RDA group. The levels of BAP in the ONFH group after the development of osteoarthritic changes were significantly lower than those observed in earlier stages. In comparisons between the samples obtained from each group with a terminal condition, the ONFH samples exhibited significantly higher MMP-3 and KS levels, while the TRACP-5 levels were highest in the RDA group.
CONCLUSION: The ONFH patients showed a relatively bone formative condition before the osteoarthritic stage and maintained a higher rate of cartilage turnover throughout several stages compared with the RDA and DDH patients. RDA patients were characterized by a significantly high osteoclast activity..
55. Motomura Goro, Takuaki Yamamoto, Koichiro Abe, Yasuharu Nakashima, Masanobu Ohishi, Satoshi Hamai, Toshio Doi, Hiroshi Honda, Yukihide Iwamoto, Scintigraphic assessments of the reparative process in osteonecrosis of the femoral head using SPECT/CT with 99mTc hydroxymethylene diphosphonate, Nuclear Medicine Communications, 35, 10, 1047-1051, 2014.10.
56. Kazuyuki Karasuyama, Takuaki Yamamoto, goro motomura, Yasuharu Nakashima, Akio Sakamoto, Ryosuke Yamaguchi, Yukihide Iwamoto, Osteonecrosis of the femoral head with collapsed medial lesion, Clinical Medicine Insights: Case Reports, 10.4137/CCRep.S18171, 7, 103-106, 2014.09, A 60-year-old female experienced the gradual onset of left hip pain without any triggering event. Radiographs showed vertical sclerosis in the center of the femoral head and the lesion inside the boundary demonstrated diffuse bony sclerosis. No collapse was observed at the weight-bearing portion on radiograph. However, computed tomography showed a subchondral collapse at the medial lesion. On T2-weighted magnetic resonance imaging, the necrotic lesion showed diffuse high-intensity signals that indicated a prominent repair process. Bone biopsy diagnosed osteonecrosis with associated prominent appositional bone and vascular granulation tissue..
57. Satoshi Ikemura, Takuaki Yamamoto, goro motomura, Ryosuke Yamaguchi, Garida Zhao, Kenyu Iwasaki, Yukihide Iwamoto, Cytochrome P4503A activity affects the gender difference in the development of steroid-induced osteonecrosis in rabbits, International Journal of Experimental Pathology, 10.1111/iep.12060, 95, 2, 147-152, 2014.04, Summary: The aim of this study was to investigate cytochrome P4503A activity and its correlation with the development of osternecrosis (ON) among male and female steroid-treated rabbits. Forty adult rabbits (male, n = 20; female, n = 20) were injected once with 20 mg/kg of methylprednisolone intramuscularly. Haematologically, cytochrome P4503A activity was measured by plasma 1′-hydroxymidazolam-to-midazolam (1′-OH-MDZ/MDZ) ratio just before and 48 h after the steroid injection. We also measured the levels of oestradiol every week. Both femora and humeri were histopathologically examined for the presence of ON. Fifteen of 20 male rabbits (75%) developed ON, while 6 of 20 female rabbits (30%) did so. There was a significant difference in the rate of incidence of ON between male and female rabbits (P = 0.010). The 1′-OH-MDZ/MDZ ratio in female rabbits just before, as well as 48 h after the steroid injection was significantly higher than that in male rabbits (P = 0.039 and P = 0.001 respectively). In addition, 1′-OH-MDZ/MDZ ratio in female rabbits significantly increased in 48 h after the steroid injection (P = 0.044), while that in male rabbits did not so (P = 0.978). The levels of oestradiol in female rabbits were significantly higher than those in male rabbits during the experimental period (P = 0.008). In conclusion, this study indicates that the gender difference in cytochrome P4503A activity may be one of the important factors for the development of steroid-induced ON, possibly due to the effects of oestradiol..
58. Yasuharu Nakashima, Masanobu Hirata, Mio Akiyama, Takashi Itokawa, Takuaki Yamamoto, goro motomura, Masanobu Ohishi, Satoshi Hamai, Yukihide Iwamoto, Combined anteversion technique reduced the dislocation in cementless total hip arthroplasty, International Orthopaedics, 10.1007/s00264-013-2091-2, 38, 1, 27-32, 2014.01, Purpose: The combined anteversion (CA) technique is a method in which the cup is placed according to the stem anteversion in total hip arthroplasty (THA). We examined whether the CA technique reduced the dislocation rate, and the distribution of CA with the manual placement of the cup. Methods: We retrospectively reviewed 634 hips in 579 patients with primary cementless THA. In 230 hips using the CA technique [CA(+)], a CA of 50 ± 10 was the aim. In the remaining 404 hips [CA(-)], the cup was first placed targeting 20 of anteversion. The post-operative CA was measured using the computed tomography (CT) images in 111 hips. Results: One hip (0.4 %) had a dislocation in the CA(+) group, whereas ten hips (2.5 %) had a dislocation in the CA(-) group. A multivariate analysis showed that primary diagnosis, head size and CA technique significantly influenced the dislocation rate. Patients in the CA(-) group were 5.8 times more likely to have a dislocation compared to the CA(+) group. In the 111 hips with CT images, 81 hips (73.0 %) achieved the intended CA. Conclusions: Although the manual placement of the cup resulted in 27 % of outliers from the intended CA, the CA technique significantly reduced the dislocation after primary THA..
59. Satoshi Hamai, Yasuharu Nakashima, Mio Akiyama, Umito Kuwashima, Takuaki Yamamoto, goro motomura, Masanobu Ohishi, Yukihide Iwamoto, Ischio-pubic stress fracture after peri-acetabular osteotomy in patients with hip dysplasia, International Orthopaedics, 10.1007/s00264-014-2375-1, 38, 10, 2051-2056, 2014.01, Methods: A total of 296 hips in 275 patients who underwent transposition osteotomy of the acetabulum between 2001 and 2012 were retrospectively reviewed. Patient characteristics and radiographic parameters were compared between patients with and without fracture.
Results: Fourteen ipsilateral hips (4.7 %) in 14 female patients had fracture of the inferior pubic ramus (11 hips) or the ischial ramus (three hips) on the same side as the surgery at an average of 4.6 weeks after PAO. Multivariate analysis indicated that younger age at operation (odds ratio of 1.43 per five years, p = 0.0169) and greater degree of correction (odds ratio of 1.98 per five degrees, p = 0.0005) were significantly associated with ischio-pubic fracture as independent risk factors. All fractures healed conservatively with partial weight-bearing.
Conclusions: Younger female patients and greater deformity corrections increased the risk of ischio-pubic stress fracture after PAO.
Purpose: Ischio-pubic stress fracture is one of the potential complications after peri-acetabular osteotomy (PAO) in patients with hip dysplasia. The purpose of this study was to examine the prevalence of and risk factors for ischio-pubic fractures following PAO..
60. goro motomura, Takuaki Yamamoto, Koichiro Abe, Yasuharu Nakashima, Masanobu Ohishi, Satoshi Hamai, Toshio Doi, Hiroshi Honda, Yukihide Iwamoto, Scintigraphic assessments of the reparative process in osteonecrosis of the femoral head using SPECT/CT with 99mTc hydroxymethylene diphosphonate, Nuclear Medicine Communications, 10.1097/MNM.0000000000000166, 35, 10, 1047-1051, 2014.01, OBJECTIVE: The aim of the study was to assess the degree and location of the reparative process in early osteonecrosis of the femoral head on the basis of single-photon emission computed tomography/computed tomography (SPECT/CT) with technetium-99m hydroxymethylene diphosphonate. MATERIALS AND METHODS: This study was approved by the institutional review board. We retrospectively evaluated SPECT/CT scans of 23 consecutive hips. On the basis of the classification system used, 12 hips were classified as stage 1 (no radiographic abnormality), six hips as stage 2 (demarcating sclerosis without femoral head collapse), and five hips as stage 3A (<3mm femoral head collapse). In each femoral head, the area with the maximum uptake count was defined as the region of maximum uptake. The degree of maximum uptake was assessed by the count ratio, which was defined as the maximum count within the femoral head divided by the mean uptake count of the cross-sectional region of the ipsilateral femur at the level of the distal end of the lesser trochanter. RESULTS: In stage 1, the maximum uptake count tended to occur in the anterior region of the femoral head. Meanwhile, in both stage 2 and stage 3A, the maximum uptake count was more likely to be observed in the lateral region. The mean count ratio of stage 2 was significantly higher than that of stage 1. CONCLUSION: We speculate that osteoblastic activity in the precollapsed stage may gradually increase around the necrotic lesion, with a tendency to advance toward the lateral region of the femoral head..
61. Keiichiro Iida, Satoshi Hamai, Takuaki Yamamoto, Yasuharu Nakashima, goro motomura, Masanobu Ohishi, Kazuyuki Karasuyama, Yukihide Iwamoto, Subchondral fracture of the femoral head after acetabular fracture
A case report, Journal of Medical Case Reports, 10.1186/1752-1947-8-447, 8, 1, 2014.01, Introduction: Preventing post-traumatic osteoarthritis is a challenging problem following acetabular fracture. Progressive osteoarthritis is considered to be caused by an irregular articular surface of the acetabular roof or cartilage injury, but little is known about the pathogenesis of collapse of the femoral head after acetabular fracture. We report a case of post-traumatic osteoarthritis after acetabular fracture in which subchondral fracture of the femoral head contributed to the progressive collapse of the femoral head and osteoarthritis. To the best of our knowledge, there has been no previous report of subchondral fracture of the femoral head after acetabular fracture. Case presentation: A 58-year-old Japanese man fell from a ladder. He was diagnosed with a left acetabular fracture, which was managed conservatively. He developed left coxalgia six months after injury and was seen at our institution one year after the onset of pain. The left acetabular fracture had fused, but his left femoral head had collapsed. The images at the time of injury showed a fracture of the acetabular roof, and an approximately 2mm step-off existed in the articular surface. Retrospective evaluation of the plain radiographs and computed tomography images showed that his femoral head had progressively collapsed. Our patient underwent total hip arthroplasty. Histopathologic findings demonstrated that the collapse of his femoral head was caused by a subchondral fracture of his femoral head. Conclusion: Our experience with this case indicates that in addition to post-traumatic osteonecrosis, subchondral fracture may need to be considered in cases with progressive collapse of the femoral head after acetabular fracture..
62. Kazuhiko Sonoda, Takuaki Yamamoto, goro motomura, Hidehiko Kido, Yukihide Iwamoto, Subchondral insufficiency fracture of the femoral head after internal fixation for femoral neck fracture
Histopathological investigation, Skeletal Radiology, 10.1007/s00256-014-1835-4, 43, 8, 1151-1153, 2014.01, Late segmental collapse after internal fixation for femoral neck fracture is the phenomenon observed in post-traumatic osteonecrosis of the femoral head (ON), which has generally been reported to occur over a year or more after internal fixation. Subchondral insufficiency fracture of the femoral head (SIF) has also been recognized to cause femoral head collapse, however, only two cases of SIF after internal fixation for femoral neck fracture have been reported. We report a case with femoral head collapse observed 5 months after internal fixation for femoral neck fracture, which was histopathologically diagnosed as SIF. Clinically, differentiating SIF from ON is important because some cases of SIF have been reported to heal without surgical treatments. The timing of femoral head collapse after femoral neck fracture may be different between SIF and post-traumatic ON..
63. Yusuke Kohno, Yasuharu Nakashima, Toshio Kitano, Tomoyuki Nakamura, Kazuyuki Takamura, Mio Akiyama, Daisuke Hara, Takuaki Yamamoto, goro motomura, Masanobu Ohishi, Satoshi Hamai, Iwamoto Yukihide, Subclinical bilateral involvement of the hip in patients with slipped capital femoral epiphysis - A multicentre study, International Orthopaedics, 10.1007/s00264-013-2131-y, 38, 3, 477-482, 2014.01, Purpose: This study was conducted to assess the posterior inclination of the contralateral femoral epiphysis in patients with unilateral slipped capital femoral epiphysis (SCFE). Methods: The posterior sloping angle (PSA) was measured using lateral radiographs in 67 patients with a unilateral SCFE and in 41 age-matched normal controls. A symptomatic epiphyseal slip was defined as the development of SCFE. Results: The contralateral PSA in SCFE patients was more widely distributed and significantly larger compared to controls (15.0°vs. 9.0°, p < 0.0001). Forty-seven hips (70.1 %) had a PSA of greater than 12.8°, which was +2SD of the control hips. Of the 65 hips excluding the two cases with prophylactic pinning, 11 hips (16.9 %) eventually developed a contralateral SCFE during adolescence and their PSA at the initial visit was significantly larger compared to patients without a contralateral SCFE (18.0°vs. 14.3°, p < 0.005) with a cutoff value of 19°. Conclusions: These findings suggested the possibility of bilateral hip involvement in SCFE patients. Hips with greater degrees of PSA (> 19°) are likely to become symptomatic..
64. Takuaki Yamamoto, goro motomura, Ryosuke Yamaguchi, Yukihide Iwamoto, The role of coagulopathy in the pathogenesis and prevention of corticosteroid-induced osteonecrosis, Osteonecrosis, 10.1007/978-3-642-35767-1_33, 249-253, 2014.01, In nontraumatic osteonecrosis (ON) of the femoral head, several abnormalities in the coagulation-fi brinolysis system have been reported, including increase of plasminogen activator inhibitor-1 level [ 1 ], the presence of antiphospholipid antibodies [ 2 ], familial heterozygous protein S defi ciency [ 3 ], and antithrombin III defi ciency [ 4 ]. These abnormalities are thought to induce hypercoagulability in the blood vessels..
65. Garida Zhao, Takuaki Yamamoto, goro motomura, Ryosuke Yamaguchi, Satoshi Ikemura, Kenyu Iwasaki, Yukihide Iwamoto, Cholesterol- and lanolin-rich diets may protect against steroid-induced osteonecrosis in rabbits, Acta Orthopaedica, 10.3109/17453674.2013.859421, 84, 6, 593-597, 2013.12, Background and purpose It remains controversial how hypercholesterolemia influences the development of steroid-induced osteonecrosis (ON). We investigated the role of hypercholesterolemia induced by a cholesterol-rich diet on the development of ON in rabbits. Methods 40 adult male Japanese white rabbits were randomly divided into 2 groups. 20 rabbits were maintained on a cholesterol-rich diet for 2 weeks before receiving steroid treatment (the CHOL group). The other 20 rabbits were maintained on a standard diet (the control (CTR) group). 2 weeks after the start of the study, all 40 rabbits were injected with methylprednisolone acetate (MPSL) into the right gluteus medius muscle (20 mg/kg body weight). 2 weeks after the steroid injection, both the femora and humeri were examined histopathologically for the presence of ON. Hematological analysis of the serum lipid levels was performed every week. Based on the same protocol, we also investigated the effects of lanolin, a primary component of a cholesterol-rich diet, in another group (the LA group). Results The incidence of ON in the CHOL group (3/20) was lower than that observed in the CTR group (15/20) (p < 0.001). During the whole experiment, the levels of total cholesterol and the ratio of low-density lipoprotein to high-density lipoprotein in the CHOL group were higher than those observed in the CTR group (p < 0.001). The LA group also had a lower incidence of ON (2/20), and the lipid levels in the LA group showed similar changes to those observed in the CHOL group. Interpretation Our findings suggest that preexisting hypercholesterolemia itself induced by a cholesterol-rich diet does not increase the risk of developing steroid-induced ON, but rather seems to diminish it. Lanolin may be the active anti-ON component of the cholesterol diet..
66. Satoshi Ikemura, Takuaki Yamamoto, goro motomura, Yasuharu Nakashima, Taro Mawatari, Yukihide Iwamoto, Erratum
The utility of clinical features for distinguishing subchondral insufficiency fracture from osteonecrosis of the femoral head (Archives of Orthopaedic and Trauma Surgery (DOI 10.1007/s00402-013-1847-x), Archives of Orthopaedic and Trauma Surgery, 10.1007/s00402-013-1863-x, 133, 12, 2013.12.
67. Mio Akiyama, Yasuharu Nakashima, Toshio Kitano, Tomoyuki Nakamura, Kazuyuki Takamura, Yusuke Kohno, Takuaki Yamamoto, goro motomura, Masanobu Ohishi, Satoshi Hamai, Yukihide Iwamoto, Remodelling of femoral head-neck junction in slipped capital femoral epiphysis
A multicentre study, International Orthopaedics, 10.1007/s00264-013-2047-6, 37, 12, 2331-2336, 2013.12, Purpose: We examined the remodelling of the femoral head-neck junction in patients with slipped capital femoral epiphysis (SCFE) and the frequency of residual cam deformities. Methods: We reviewed 69 hips in 56 patients with stable SCFE who had undergone in situ pinning. Mean age at slip was 11.7 years and the follow-up period 63.4 months. Cam deformity was evaluated using the anterior offset alpha (α) angle and head-neck offset ratio (HNOR). Results: The average α angle and HNOR significantly improved from 76.2 to 51.3 and 0.086 to 0.135, respectively; 25 hips (36.2 %) still had an α angle greater than 50, and 32 hips (46.4 %) had an HNOR of under 0.145. A multivariate analysis selected age at onset and slip angle as risk factors for cam deformity, with cutoff values 11.1 years and 21.0, respectively. Conclusions: Although most hips had remodelling of the head-neck junction, 29.4 % had residual cam deformities that may be susceptible to femoroacetabular impingement..
68. Satoshi Ikemura, Takuaki Yamamoto, goro motomura, Yasuharu Nakashima, Taro Mawatari, Yukihide Iwamoto, The utility of clinical features for distinguishing subchondral insufficiency fracture from osteonecrosis of the femoral head, Archives of Orthopaedic and Trauma Surgery, 10.1007/s00402-013-1847-x, 133, 12, 1623-1627, 2013.12, Purpose: Subchondral insufficiency fractures of the femoral head (SIF) need to be differentiated from osteonecrosis of the femoral head (ON), since these two conditions have several overlapping characteristics especially in their radiological findings. The purpose of this study was to determine the useful clinical features for differentiating SIF from ON. Methods: This study reviewed 44 consecutive patients, aged 60 years or older with a radiological evidence of subchondral collapse of the femoral head. According to the histopathological diagnosis, 22 patients were grouped as SIF and 22 patients as ON. A 2 × 2 contingency table analysis was used to obtain the odd ratios (ORs) for SIF compared to ON. Results: The age, proportion of females, the rate of a history of either corticosteroid intake or alcohol abuse, and the presence of vertebral compression fracture in subchondral insufficiency fracture were significantly higher than those with osteonecrosis (p = 0.0001, 0.0212, 0.0001, and 0.0040, respectively). ORs for SIF were 12.01 [95 % confidence intervals (CI) 1.35-106.80] and 7.29 (95 % CI 1.91-27.86), if the patient were female and 70 years of age or older, respectively. In addition, OR for SIF was extremely high (OR 56.01, 95 % CI 6.12-512.87) compared to ON, if the patients have a history of either corticosteroid intake or alcohol abuse. Conclusion: The results of this study indicate that osteoporotic elderly women without any history of corticosteroid intake or alcohol abuse need to first be considered to have subchondral insufficiency fracture when radiographs show a collapse of the femoral head..
69. Takashi Itokawa, Yasuharu Nakashima, Takuaki Yamamoto, goro motomura, Masanobu Ohishi, Satoshi Hamai, Mio Akiyama, Masanobu Hirata, Daisuke Hara, Yukihide Iwamoto, Late dislocation is associated with recurrence after total hip arthroplasty, International Orthopaedics, 10.1007/s00264-013-1921-6, 37, 8, 1457-1463, 2013.08, Purpose: This study was conducted to examine the risk factors for recurrent dislocation after total hip arthroplasty (THA) and test the hypothesis that late dislocations are associated with recurrence. Methods: A total of 1,250 hips in 1,017 patients were retrospectively reviewed. All operations were performed through the posterolateral approach with posterior soft tissue repair. An early or late dislocation was defined as a dislocation occurring before or after one year postoperatively, respectively. Results: Dislocation occurred in 36 hips (2.9 %) and 20 of them experienced recurrence. Recurrent dislocations were observed in ten out of 25 hips (40.0 %) with early dislocation; however, ten out of 11 hips (90.9 %) with late dislocation experienced recurrence (p = 0.0046). Multivariate analysis revealed that late dislocation was significantly associated with recurrence with odds ratio of 5.94 per year. Seven in 20 hips with recurrent dislocation required surgical treatment. Conclusion: Late dislocation significantly contributed to the development of recurrent dislocations..
70. Kenyu Iwasaki, Takuaki Yamamoto, goro motomura, Satoshi Ikemura, Ryosuke Yamaguchi, Yukihide Iwamoto, Radiologic measurements associated with the prognosis and need for surgery in patients with subchondral insufficiency fractures of the femoral head, American Journal of Roentgenology, 10.2214/AJR.12.9615, 201, 1, 2013.07, OBJECTIVE. The objective of this study was to identify the risk factors associated with the prognosis and need for surgery of patients with subchondral insufficiency fractures of the femoral head. MATERIALS AND METHODS. Twenty-nine consecutively registered patients with subchondral insufficiency fractures of the femoral head were divided into the two groups: a nonprogression of collapse group, which included patients who had no collapse or 2 mm or less of collapse of the femoral head and whose symptoms resolved (14 patients), and a progression of collapse group, which included patients who had more than 2 mm of collapse, for which surgery was indicated (15 patients). Both groups received the same conservative therapy. The following radiographic measurements were obtained: Sharp angle, center edge angle, acetabular roof angle, and acetabular head index. On MR images, band length, defined as the length of a lowsignal-intensity band in the coronal plane, and band length ratio, defined as the proportion of the band length relative to the weight bearing portion, were assessed for each patient. Bone mineral density measurements (T score) were available for 17 patients. RESULTS. In the univariate analyses, T score, Sharp angle, center edge angle, acetabular roof angle, acetabular head index, band length, and band length ratio were found to be significant prognostic factors. Multivariate analyses of T score, acetabular head index, and band length ratio showed that both acetabular head index and band length ratio were significant predictors. CONCLUSION. Both acetabular head index and band length ratio are important prognostic factors in the care of patients with subchondral insufficiency fractures of the femoral head..
71. Satoshi Ikemura, Takuaki Yamamoto, goro motomura, Ryosuke Yamaguchi, Garida Zhao, Kenyu Iwasaki, Yukihide Iwamoto, Preventive effects of the anti-vasospasm agent via the regulation of the Rho-kinase pathway on the development of steroid-induced osteonecrosis in rabbits, Bone, 10.1016/j.bone.2012.12.050, 53, 2, 329-335, 2013.04, A number of studies have suggested that ischemia is the principal pathomechanism of osteonecrosis, however, the detailed mechanism responsible for ischemia remains unclear. We examined the effects of fasudil, an anti-vasospasm agent, on the development of steroid-induced osteonecrosis in rabbits. One group of rabbits received 15mg/kg of fasudil intravenously, which were then injected once intramuscularly with 20mg/kg of methylprednisolone (n=33), and one received methylprednisolone alone as a control (n=28). Eight rabbits from each group were sacrificed 24h after methylprednisolone injection to analyze them by the expression of endothelinA-receptor and eNOS. Two weeks after the steroid injection, the femora and humeri were examined histopathologically for the incidence of osteonecrosis. In addition, plasma from each of four osteonecrosis-positive or -negative rabbits was used for the proteomic analysis in the fasudil group. The incidence of osteonecrosis was significantly lower in the fasudil group (32%) than that in the control group (75%) (P<0.01). Immunohistochemically, endothelinA-receptor expressions levels were decreased in the smooth muscle of the bone marrow in the fasudil group in comparison to that in the control group. The eNOS expressions levels in both serum and bone marrow in the MF group were significantly higher than those in the M group (P<0.05). Based on the proteomic analysis, several proteins related to vasospasm, such as fibrinogen, thrombin, and apolipoprotein E, were identified in rabbits with osteonecrosis soon after steroid administration. This study indicates that vasospasm is one of the important factors involved in the pathogenesis of steroid-induced osteonecrosis and that the anti-vasospasm agents seem to decrease the incidence of steroid-induced osteonecrosis..
72. Yuma Sakamoto, Takuaki Yamamoto, goro motomura, Akio Sakamoto, Ryosuke Yamaguchi, Kenyu Iwasaki, Garida Zhao, Kazuyuki Karasuyama, Yukihide Iwamoto, Osteonecrosis of the femoral head extending into the femoral neck, Skeletal Radiology, 10.1007/s00256-012-1525-z, 42, 3, 433-436, 2013.03, Osteonecrosis of the femoral head (ONFH) is an ischemic disorder that can lead to femoral head collapse and secondary osteoarthritis. Although the condition is usually limited to the femoral head, we report a rare case of biopsy-proven ONFH extending into the femoral neck, which required hip replacement surgery. We emphasize the imaging features of this condition and briefly discuss its potential relevance..
73. Yasuharu Nakashima, Naohiko Mashima, Hiroshi Imai, Naoto Mitsugi, Naoya Taki, Yuichi Mochida, Ichiro Owan, Kaoru Arakaki, Takuaki Yamamoto, Taro Mawatari, goro motomura, Masanobu Ohishi, Toshio Doi, Masayuki Kanazawa, Yukihide Iwamoto, Clinical and radiographic evaluation of total hip arthroplasties using porous tantalum modular acetabular components
5-year follow-up of clinical trial, Modern Rheumatology, 10.1007/s10165-012-0618-9, 23, 1, 112-118, 2013.01, Objectives: Porous tantalum is a biomaterial newly applied for artificial joints. We present here 5-years follow-up report of a multicenter clinical trial of total hip arthroplasties (THA) with porous tantalum modular acetabular component (modular PTC). Methods: Study participants received 82 hips in 79 cases, with 61.2 months follow-up on average. Age at operation was 60.9 years. Clinical results were evaluated using Merle d'Aubigne Postel score. Presence of implant loosening, periacetabular radiolucency, osteolysis, and gap filling were examined for radiographic results. Results: Merle d'Aubigne Postel score improved from 10.0 to 16.4 points. All PTC were radiographically stable, with no evidence of progressive radiolucencies. Average polyethylene wear rate was 0.004 mm/year, with no periacetabular osteolysis. Fifteen hips (18.3%) showed a gap >1 mm; however, all showed bone filling within 12 months. PTC with oversized reaming was significantly less likely to have a gap. No implant failure was noted related to modularity. Resulting survival rate of modular PTC was 100% at 5 years. Conclusions: Modular PTC showed excellent results at 5-years of follow-up. Some hips showed periacetabular gaps, which were filled with bone within 1 year. Further follow-up was needed to determine long-term efficacy..
74. Taishi Sato, Yasuharu Nakashima, Mio Akiyama, Takuaki Yamamoto, Taro Mawatari, Takashi Itokawa, Masanobu Ohishi, goro motomura, Masanobu Hirata, Yukihide Iwamoto, Comparison of polyethylene wear between highly crosslinked and annealed UHMWPE and conventional UHMWPE against ceramic heads in total hip arthroplasty, 24th Symposium and Annual Meeting of International Society for Ceramics in Medicine, ISCM 2012 Bioceramics 24, 10.4028/www.scientific.net/KEM.529-530.279, 279-284, 2013.01, The purpose of this study was to examine the effects of ceramic femoral head material on the wear of annealed, crosslinked ultra-high molecular weight polyethylene (UHMWPE) (XLPE) in total hip arthroplasty compared to non-crosslinked conventional UHMWPE (CPE). XLPE was fabricated by crosslinking with 60 kGy irradiation and annealing. Femoral heads made from zirconia and alumina ceramics, and cobalt-chrome (CoCr) of 22 mm or 26 mm diameter were used. In this study, the femoral head penetration into the cup was measured digitally on radiographs of 70 hips with XLPE and 50 hips with CPE. The average follow-up periods were 6.1 and 12.7 years, respectively. The steady wear rate of XLPE was significantly lower than those of CPE (0.002 versus 0.08 mm/year, respectively). Zirconia displayed increased wear rates compared to alumina in CPE; however, there was no difference among head materials in XLPE (0.0028, 0.011 and 0.009 mm/year for zirconia, alumina and CoCr, respectively). Neither head size or implantation period impacted XLPE wear. In contrast to CPE, XLPE displayed low wear rates surpassing the effects of varying femoral head material, size, implantation period and patient demographics..
75. Garida Zhao, Takuaki Yamamoto, goro motomura, Kenyu Iwasaki, Ryosuke Yamaguchi, Satoshi Ikemura, Yukihide Iwamoto, Radiological outcome analyses of transtrochanteric posterior rotational osteotomy for osteonecrosis of the femoral head at a mean follow-up of 11 years, Journal of Orthopaedic Science, 10.1007/s00776-012-0347-0, 18, 2, 277-283, 2013.01, Background: This study investigated the radiological factors that correlated with progression of collapse and joint space narrowing after transtrochanteric posterior rotational osteotomy (PRO) for osteonecrosis of the femoral head. Methods: This study reviewed 51 hips in 47 patients with a mean follow-up of 11 years (5-20). The subjects included 29 males and 18 females with a mean age of 34 years (12-54) at the time of surgery. The 51 hips were divided into two groups based on the radiological outcome (group I: evidence of progression of collapse and/or joint space narrowing, group II: no evidence of either progression of collapse or joint space narrowing). Both clinical and radiological factors were analyzed by both univariate and multivariable analyses. Results: Six hips were categorized as group I and 45 hips were categorized as group II. The postoperative intact ratio and preoperative stage were significantly correlated with the radiological outcome in both univariate (P < 0.0001, P = 0.006) and multivariate (P = 0.0014, P = 0.0039) analysis. The cutoff point for the postoperative intact ratio (the minimum ratio required to prevent both progression of collapse and joint space narrowing) was 36.8 %. Conclusions: The results of this study indicate that the postoperative intact ratio is one of the main influences on progression of collapse and/or joint space narrowing after PRO, and should be at least 36.8 %. An increased awareness of this critical ratio would be useful for planning the optimal use of this procedure..
76. Yasuharu Nakashima, Taishi Sato, Takuaki Yamamoto, goro motomura, Masanobu Ohishi, Satoshi Hamai, Mio Akiyama, Masanobu Hirata, Daisuke Hara, Yukihide Iwamoto, Results at a minimum of 10 years of follow-up for AMS and PerFix HA-coated cementless total hip arthroplasty
Impact of cross-linked polyethylene on implant longevity, Journal of Orthopaedic Science, 10.1007/s00776-013-0456-4, 18, 6, 962-968, 2013.01, Purpose: The purpose of this study was to report results at a minimum of 10 years for hydroxyapatite (HA) coating on the titanium arc-sprayed cementless total hip arthroplasty (THA) and to evaluate the impact of cross-linked polyethylene (XLPE) on implant longevity. Methods: A total of 131 consecutive primary THAs in 123 patients using an AMS acetabular cup and a PerFix HA stem were retrospectively reviewed. Conventional PE was used for 62 hips (CPE group) and cross-linked PE for 69 hips (XLPE group), with mean follow-up periods of 13 and 11.5 years, respectively. These patients were reviewed using the Japanese Orthopaedic Association (JOA) Hip Score and evaluated in terms of PE wear, osteolysis, and implant survival. Results: The JOA score improved from 42.6 to 83.9 points at the final follow-up. The mean wear rate of 0.12 mm/year in the CPE group was significantly greater than that of XLPE at 0.007 mm/year. In the CPE group, ten (16.1 %) and two (3.2 %) hips, respectively, underwent PE exchange due to severe wear and acetabular revision due to loosening associated with osteolysis. Three patients had revision in the XLPE group: one cup for aseptic loosening, one PE for recurrent dislocation, and one stem for neck fracture. No evident osteolysis was seen in the XLPE group. Kaplan-Meier survivorship with any revision as the end point shows that the 12-year survival rate was 97.7 % for cups, 93.8 % for PE liners, and 99.2 % for stems. Multivariate analysis revealed that the use of XLPE significantly reduced the risk of revision, with the odds ratio (OR) of 4.3. Conclusions: AMS and PerFix HA components in this series show excellent implant fixation; however, high rates of PE wear and subsequent osteolysis were limiting factors in long-term success. Low wear rates with XLPE suggest improved implant longevity..
77. Taishi Sato, Yasuharu Nakashima, Mio Akiyama, Takuaki Yamamoto, Taro Mawatari, Takashi Itokawa, Masanobu Ohishi, goro motomura, Masanobu Hirata, Yukihide Iwamoto, Wear resistant performance of highly cross-linked and annealed ultra-high molecular weight polyethylene against ceramic heads in total hip arthroplasty, Journal of Orthopaedic Research, 10.1002/jor.22148, 30, 12, 2031-2037, 2012.12, The purpose of this study was to examine the effects of ceramic femoral head material, size, and implantation periods on the wear of annealed, cross-linked ultra-high molecular weight polyethylene (UHMWPE) (XLPE) in total hip arthroplasty compared to non-cross-linked conventional UHMWPE (CPE). XLPE was fabricated by cross-linking with 60 kGy irradiation and annealing. Femoral heads made from zirconia and alumina ceramics and cobalt-chrome (CoCr) of 22 or 26 mm diameter were used. In this retrospective cohort study, the femoral head penetration into the cup was measured digitally on radiographs of 367 hips with XLPE and 64 hips with CPE. The average follow-up periods were 6.3 and 11.9 years, respectively. Both XLPE creep and wear rates were significantly lower than those of CPE (0.19 mm vs. 0.44 mm, 0.0001 mm/year vs. 0.09 mm/year, respectively). Zirconia displayed increased wear rates compared to alumina in CPE; however, there was no difference among head materials in XLPE (0.0008, 0.00007, and -0.009 mm/year for zirconia, alumina, and CoCr, respectively). Neither head size or implantation period impacted XLPE wear. In contrast to CPE, XLPE displayed low wear rates surpassing the effects of varying femoral head material, size, implantation period, and patient demographics. Further follow-up is required to determine the long-term clinical performance of the annealed XLPE..
78. Mio Akiyama, Yasuharu Nakashima, Masanori Fujii, Taishi Sato, Takuaki Yamamoto, Taro Mawatari, goro motomura, Shuichi Matsuda, Yukihide Iwamoto, Femoral anteversion is correlated with acetabular version and coverage in Asian women with anterior and global deficient subgroups of hip dysplasia
A CT study, Skeletal Radiology, 10.1007/s00256-012-1368-7, 41, 11, 1411-1418, 2012.11, Objective: Morphological correlation between the acetabulum and femur at the hip joint is still controversial. We tested the hypothesis that femoral anteversion correlates with acetabular version and coverage in patientswith developmental dysplasia of the hip (DDH). Materials and methods: Using pelvic computed tomography (CT) images of 79 hips in 49 Asian women with DDH and 49 normal hips, we measured femoral anteversion, the axial and vertical acetabular version and the acetabular sector angle (ASA) to demarcate femoral head coverage. Depending on the location of the acetabular bone defect, dysplastic hips were divided into three subgroups: the anterior, global and posterior deficiency groups. We performed a comparative analysis between dysplastic and normal hips using the Wilcoxon rank sum test, and a relative analysis between femoral anteversion and acetabular measurements in dysplastic hips using Pearson's correlation coefficient. Results: The amount of femoral anteversion in dysplastic hips was greater and more variable than in normal hips (p<0.0001, p00.0277 respectively). Femoral anteversion in dysplastic hips correlated significantly with acetabular anteversion in the groups with anterior and global deficiency subgroups (p<0.05, r00.2990, p<0.05, r00.451 respectively), but not with the posterior deficiency subgroup. Femoral anteversion also correlated with vertical acetabular version. When acetabular coverage was examined, significant correlations were noted between femoral anteversion and anterior and superior coverage, but not with posterior coverage. These correlations were not observed in normal hips. Conclusions: Our results showed significantly greater and more variable femoral anteversion in DDH, and a significant correlation between femoral anteversion and acetabular version and coverage in DDH with anterior and global acetabular bone deficiency..
79. Motomura G, Yamamoto T, Nakashima Y, Yamaguchi R, Mawatari T, Iwamoto Y., Midterm results of transtrochanteric anterior rotational osteotomy combined with shelf acetabuloplasty for osteonecrosis with acetabular dysplasia: a preliminary report., J Orthop Sci. , 17, 3, 239-43, 2012.05.
80. Ryosuke Yamaguchi, Takuaki Yamamoto, goro motomura, Satoshi Ikemura, Kenyu Iwasaki, Garida Zhao, Yukihide Iwamoto, Effects of an anti-platelet drug on the prevention of steroid-induced osteonecrosis in rabbits, Rheumatology, 10.1093/rheumatology/ker197, 51, 5, 789-793, 2012.05, Objective: To investigate the effects of an anti-platelet drug (clopidogrel) on the prevention of steroid-induced osteonecrosis (ON) in rabbits. Methods: Adult male Japanese white rabbits were divided into two groups and treated as follows: one group received daily clopidogrel mixed in normal saline (AP; n = 35), the other received only normal saline (NS; n = 30). One week after the administration, all rabbits were injected once intramuscularly with 20 mg/kg of methylprednisolone acetate into the right gluteus medius muscle. Three weeks after, both the femora and humeri were examined histopathologically for the presence of ON. The platelet aggregation assay and hematological examinations were performed before and after the steroid injection. Results: The incidence of ON in the AP group (48.5%) was significantly lower than that observed in the NS group (73.3%). The platelet aggregations in the AP group were significantly inhibited by the administration of clopidogrel. The levels of total cholesterol and triglycerides showed no significant differences between the AP and NS group. Conclusion: The present experimental study demonstrated that the administration of an anti-platelet drug prevented steroid-induced ON in rabbits and that platelet aggregation seems to be one of the possible factors involved in the pathogenesis of steroid-induced ON..
81. Motomura G, Yamamoto T, Inoue S, Nakashima Y, Mawatari T, Iwamoto Y., Subclinical infection associated with delayed union after transtrochanteric rotational osteotomy, Orthopedic Research and Reviews, 4, 5-8, 2012.04.
82. K. Iwasaki, Takuaki Yamamoto, goro motomura, Satoshi Ikemura, T. Mawatari, Yasuharu Nakashima, Y. Iwamoto, Prognostic factors associated with a subchondral insufficiency fracture of the femoral head, British Journal of Radiology, 10.1259/bjr/44936440, 85, 1011, 214-218, 2012.03, Objective: The aim of this study was to identify the risk factors associated with the prognosis of a subchondral insufficiency fracture of the femoral head (SIF). Methods: Between June 2002 and July 2009, 25 patients diagnosed with SIF were included in this study. Sequential radiographs were evaluated for the progression of collapse. Clinical profiles, including age, body mass index, follow-up period and Singh's index, were documented. The morphological characteristics of the low-intensity band on T 1 weighted MRI were also examined with regards to four factors: band length, band thickness, the length of the weight-bearing portion and the band length ratio (defined as the proportion of the band length to the weight-bearing portion of the femoral head in the slice through the femoral head centre). Results: Radiographically, a progression of collapse was observed in 15 of 25 (60.0%) patients. The band length in patients with progression of collapse [22.5 mm; 95% confidence interval (CI) 17.7, 27.3] was significantly larger than in patients without a progression of collapse (13.4 mm; 95% CI 7.6, 19.3; p<0.05). The band length ratio in patients with progression of collapse (59.8%; 95% CI 50.8, 68.9) was also significantly higher than in patients without a progression of collapse (40.9%; 95% CI 29.8, 52.0; p<0.05). No significant differences were present in the other values. Conclusion: These results indicate that the band length and the band length ratio might be predictive for the progression of collapse in SIF..
83. Satoshi Ikemura, Takuaki Yamamoto, goro motomura, Kenyu Iwasaki, Ryosuke Yamaguchi, Garida Zhao, Yukihide Iwamoto, Authors' reply, International Journal of Experimental Pathology, 10.1111/j.1365-2613.2011.00798_2.x, 93, 1, 79-80, 2012.02.
84. Garida Zhao, Takuaki Yamamoto, Satoshi Ikemura, goro motomura, Kenyu Iwasaki, Ryosuke Yamaguchi, Yasuharu Nakashima, Taro Mawatari, Yukihide Iwamoto, Clinico-radiological factors affecting the joint space narrowing after transtrochanteric anterior rotational osteotomy for osteonecrosis of the femoral head, Journal of Orthopaedic Science, 10.1007/s00776-012-0238-4, 17, 4, 390-396, 2012.01, Purpose The purpose of this study was to investigate the factors that affect the joint space narrowing after transtrochanteric anterior rotational osteotomy (ARO) for osteonecrosis of the femoral head (ONFH). Methods We reviewed 39 cases (43 hips) of ONFH in patients who underwent ARO between 2000 and 2004. Their mean age was 42 years (23-61) at the time of surgery. The mean follow-up period was 7.3 years (3-10). The following clinical and radiological factors were investigated: the preoperative stage, localization and extent of the necrotic lesion, and the postoperative intact ratio (transposed intact articular surface of the femoral head to the weight-bearing surface of the acetabulum). The 43 hips were divided into two groups: a joint space narrowing (JSN) group and a non-joint space narrowing (non-JSN) group. Results Thirty-seven hips (86 %) were categorized as non-JSN and six (14 %) as having JSN. The preoperative Japanese Orthopaedic Association score was significantly higher in the non-JSN group than in the JSN group (P = 0.01). In the non-JSN group, the rate of early stage disease was significantly higher than in the JSN group (P = 0.03). The postoperative intact ratio was significantly higher in the non-JSN group than in the JSN group (P = 0.002). A multivariate analysis revealed that the postoperative intact ratio was an independent predictor of the progression of joint space narrowing after ARO, and the cutoff point was 39.2 %. Conclusion The results of this study suggest that the postoperative intact ratio is one of factors determining the progression of joint space narrowing after ARO and that an approximately 40 % or higher postoperative intact ratio is recommended to prevent joint space narrowing..
85. Shinya Kawahara, Yasuharu Nakashima, Hiroshi Oketani, Akifusa Wada, Masanori Fujii, Takuaki Yamamoto, Taro Mawatari, goro motomura, Taishi Sato, Mio Akiyama, Toshio Fujii, Kazuyuki Takamura, Yukihide Iwamoto, High prevalence of acetabular retroversion in both affected and unaffected hips after Legg-Calvé-Perthes disease, Journal of Orthopaedic Science, 10.1007/s00776-012-0213-0, 17, 3, 226-232, 2012.01, Background Acetabular retroversion is observed in hips after various pediatric hip diseases. This study sought to examine the frequency of acetabular retroversion in both affected and unaffected hips after Legg-Calvé- Perthes disease and its correlation with the prominence of the ischial spine. Methods We retrospectively investigated the version and morphological features of the acetabulum using pelvic radiographs after Legg-Calvé-Perthes disease (107 affected hips treated non-operatively and 72 unaffected hips from the contralateral side). The diagnosis of acetabular retroversion was made based on the presence of a positive cross-over sign on anteroposterior pelvic radiographs. The correlation between the presence of a positive cross-over sign and modified Stulberg classes, the onset age of Legg-Calvé-Perthes disease, radiographic parameters for acetabular dysplasia and the prominence of the ischial spine were examined. Results The prevalence of a positive cross-over sign was 49.5 % (45 of 91 hips) in affected hips and 45.8 % (33 of 72 hips) in unaffected hips. Hips with a positive cross-over sign were significantly coexistent bilaterally. The prevalence of prominence of the ischial spine in the positive cross-over sign group was 71.4 % in the affected side and 81.8 % in the unaffected side, indicating a significant correlation between the cross-over sign and the prominence of the ischial spine in both affected and unaffected hips. The positive cross-over sign did not have any correlation with the parameters for acetabular dysplasia and the onset age, however, had a significant correlation with the severity of the femoral head deformity. Conclusions High prevalence of acetabular retroversion in both affected and unaffected hips after Legg-Calvé-Perthes disease was demonstrated. Symmetric acetabular deformity and the coexistence of prominence of the ischial spine suggested the effects of the Legg-Calvé-Perthes disease lesions on the skeletal development of the whole pelvis. Further follow-up is needed to clarify the pathological significance of acetabular retroversion after Legg-Calvé-Perthes disease..
86. goro motomura, Takuaki Yamamoto, Yasuharu Nakashima, Ryosuke Yamaguchi, Taro Mawatari, Yukihide Iwamoto, Midterm results of transtrochanteric anterior rotational osteotomy combined with shelf acetabuloplasty for osteonecrosis with acetabular dysplasia
A preliminary report, Journal of Orthopaedic Science, 10.1007/s00776-012-0205-0, 17, 3, 239-243, 2012.01, Background Transtrochanteric anterior rotational osteotomy for osteonecrosis of the femoral head should be performed to obtain [34% of the ratio of transposed intact posterior articular surface to the acetabular weight-bearing area. Therefore, the presence of acetabular dysplasia is unfavorable in obtaining this ratio. Between 1999 and 2005, we performed the modified Spitzy shelf acetabuloplasty combined with anterior rotational osteotomy for three patients (four hips) with acetabular dysplasia. In this study, we retrospectively evaluated the midterm results of this combined surgery. Methods and results Patients comprised one man and two women with a mean age of 29 years at the time of surgery. Mean follow-up was 7.5 years. The average preoperative Harris hip score of 65.5 points increased to an average of 79.3 points at the latest follow-up. None of the hips required conversion to total hip arthroplasty during the follow-up periods. The average postoperative intact ratio without a shelf procedure was 23%, and with a shelf procedure, this ratio increased to be 58%. As a result, collapse progression was not observed in any of the four hips. Conclusions Our results suggest that anterior rotational osteotomy combined with shelf acetabuloplasty may be a surgical option for osteonecrosis of the femoral head with acetabular dysplasia. Further studies with a larger patient population are necessary to clarify appropriate indications and limitations of this combined surgery..
87. Masanori Fujii, Yasuharu Nakashima, Y. Noguchi, T. Yamamoto, T. Mawatari, goro motomura, Y. Iwamoto, Effect of intra-articular lesions on the outcome of periacetabular osteotomy in patients with symptomatic hip dysplasia, Journal of Bone and Joint Surgery - Series B, 10.1302/0301-620X.93B11.27314, 93 B, 11, 1449-1456, 2011.11, In order to clarify how intra-articular lesions influence the survival of a periacetabular osteotomy in patients with dysplasia of the hip, we performed an observational study of 121 patients (121 hips) who underwent a transposition osteotomy of the acetabulum combined with an arthroscopy. Their mean age was 40.2 years (13 to 64) and the mean follow-up was 9.9 years (2 to 18). Labral and cartilage degeneration tended to originate from the anterosuperior part of the acetabulum, followed by the femoral side. In all, eight hips (6.6%) had post-operative progression to Kellgren-Lawrence grade 4 changes, and these hips were associated with the following factors: moderate osteoarthritis, decreased width of the joint space, joint incongruity, and advanced intra-articular lesions (subchondral bone exposure in the cartilage and a full-thickness labral tear). Multivariate analysis indicated subchondral bone exposure on the femoral head as an independent risk factor for progression of osteoarthritis (p = 0.003). In hips with early stage osteoarthritis, femoral subchondral bone exposure was a risk factor for progression of the grade of osteoarthritis. Although the outcome of transposition osteotomy of the acetabulum was satisfactory, post-operative progression of osteoarthritis occurred at a high rate in hips with advanced intra-articular lesions, particularly in those where the degenerative process had reached the point of femoral subchondral bone exposure..
88. Ryosuke Yamaguchi, Takuaki Yamamoto, goro motomura, Satoshi Ikemura, Yukihide Iwamoto, Incidence of nontraumatic osteonecrosis of the femoral head in the Japanese population, Arthritis and rheumatism, 10.1002/art.30484, 63, 10, 3169-3173, 2011.10, Objective To estimate the incidence rate of nontraumatic osteonecrosis of the femoral head (ONFH) in the Japanese population. Methods A survey was conducted to ascertain newly identified patients with nontraumatic ONFH in the Specified Disease Treatment Research Program of Fukuoka Prefecture (population 5 million) between 1999 and 2008. Distributions of age and sex in this population were investigated. Crude incidence rates of nontraumatic ONFH were calculated, and age-adjusted incidence rates were estimated by adjusting the crude values against those for the Japanese standard population in each year. Results In Fukuoka Prefecture, 1,244 newly identified patients with nontraumatic ONFH were recruited into the Japanese subsidy program over the span of 10 years. The ratio of men to women was 1.6, comprising 758 men (61%; mean age 48 years) and 486 women (39%; mean age 56 years). The crude incidence rate of nontraumatic ONFH in the 10-year period was 2.58 cases per 100,000 person-years (range 1.54-3.66). The mean age-adjusted incidence rate was 2.51 cases per 100,000 person-years. Conclusion This study showed that the incidence rate of nontraumatic ONFH was 2.51 cases per 100,000 person-years in the Japanese population..
89. Yasuharu Nakashima, Hideaki Kubota, Takuaki Yamamoto, Taro Mawatari, goro motomura, Yukihide Iwamoto, Transtrochanteric rotational osteotomy for late-onset Legg-Calve-Perthes disease, Journal of Pediatric Orthopaedics, 10.1097/BPO.0b013e318223b4f3, 31, SUPPL. 2, 2011.09, Background: The pathology of late-onset Legg-Calve-Perthes disease (LCPD) is similar to that of avascular necrosis of the femoral head in adult and is associated with poorer prognosis of the hip. The optimal treatment for this condition is still controversial. The purpose of this study was to evaluate the long-term clinical results of the transtrochanteric rotational osteotomy for the patients with LCPD onset at more than 9 years of age. Methods: Individuals included 14 hips in 13 cases with the mean age at onset of the disease and operation of 10 years 9 months and 12 years. Average follow-up periods were 12 years. All cases were resistant to the conservative treatments and did not have our indications for varus osteotomy. Clinical results were evaluated using Merle d'Aubigne Postel score and the modified Stulberg criteria. Results: Average Merle d'Aubigne Postel score at the final follow-up was 16.2 points ranging from 12 to 18 points. All patients did not have additional treatment except nail removal. Stulberg class II, III, and IV were obtained in 5, 2, and 7 hips, respectively. More spherical femoral head was obtained in patients with less head involvement and more bone preservation or new bone formation at posterior pillar. Three hips showed slight narrowing of joint space without severe osteoarthritic changes. Conclusions: Transtrochanteric rotational osteotomy is an effective procedure to salvage the hips of the late-onset LCPD. Amount of head involvement, posterior and lateral pillar had influences on the surgical outcomes..
90. Satoshi Ikemura, Takuaki Yamamoto, goro motomura, Kenyu Iwasaki, Ryosuke Yamaguchi, Garida Zhao, Yukihide Iwamoto, Lipid metabolism abnormalities in alcohol-treated rabbits
A morphometric and haematologic study comparing high and low alcohol doses, International Journal of Experimental Pathology, 10.1111/j.1365-2613.2011.00773.x, 92, 4, 290-295, 2011.08, The pathogenesis of alcohol-induced osteonecrosis remains unclear. The purpose of the present study was to evaluate the morphological changes in bone marrow fat cells and the changes in the serum lipid levels in alcohol-treated rabbits. Fifteen rabbits were randomly assigned into three groups: Four rabbits intragastrically received low-dose alcohol (LDA) (15ml/kg per day) containing 15% ethanol for 4weeks, five rabbits received high-dose alcohol (HDA) (30ml/kg per day) for 4weeks and six rabbits received physiologic saline for 4weeks as a control group. Six weeks after the initial alcohol administration, all rabbits were sacrificed. The mean size of the bone marrow fat cells in rabbits treated with HDA was significantly larger than that in the control group (P=0.0001). Haematologically, the levels of triglycerides and free fatty acids in the rabbits treated with both low-dose and HDA were significantly higher than those in the control group (P=0.001 for both comparisons). The results of this study are that there are lipid metabolism abnormalities, both morphologically and haematologically, after alcohol administration. Also these findings were more apparent in rabbits treated with HDA than those treated with LDA..
91. Iwasaki K, Yamamoto T, Motomura G, Mawatari T, Nakashima Y, Iwamoto Y, Subchondral insufficiency fracture of the femoral head in young adults, Clinical Imaging, 35, 3, 208-13, 2011.05.
92. Kenyu Iwasaki, Takuaki Yamamoto, goro motomura, Taro Mawatari, Yasuharu Nakashima, Yukihide Iwamoto, Subchondral insufficiency fracture of the femoral head in young adults, Clinical Imaging, 10.1016/j.clinimag.2010.05.005, 35, 3, 208-213, 2011.05, A subchondral insufficiency fracture of the femoral head (SIF) is generally observed in elderly women. In addition, SIF has been reported to occur in young military trainees, which are considered to be due to a fatigue stress fracture. This report reviewed five cases of SIF in young adults without any history of overexertion or antecedent trauma. The clinical findings, time to the initial radiograph, time to the initial magnetic resonance imaging (MRI), and follow-up period were investigated. Radiographs and MRI were obtained in both hips. Bone mineral density and bone scintigram were performed. Measurements of a bone mineral density indicated presence of osteopenia in three patients. MRI disclosed a discontinuous irregular-shaped low-intensity band surrounded by bone marrow edema in all cases. After conservative treatments, one patient's condition resolved, while four patients underwent femoral head collapse resulting in surgical treatment. In these four patients, the diagnosis of SIF was histologically confirmed. In addition, the histological findings showed thin disconnected bone trabeculae, thus indicating the presence of some degree of osteopenia. These patients were considered to demonstrate an insufficiency fracture rather than a fatigue stress fracture based on both clinical findings and histological findings. SIF needs to be considered in patients presenting with hip pain even in young cases..
93. Motomura G, Yamamoto T, Yamaguchi R, Ikemura S, Nakashima Y, Mawatari T, Iwamoto Y, Morphological Analysis of Collapsed Regions in Osteonecrosis of the Femoral Head, Journal of Bone and Joint Surgery, British volume, 93, 2, 184-7, 2011.02.
94. goro motomura, T. Yamamoto, Ryosuke Yamaguchi, Satoshi Ikemura, Yasuharu Nakashima, T. Mawatari, Y. Iwamoto, Morphological analysis of collapsed regions in osteonecrosis of the femoral head, Journal of Bone and Joint Surgery - Series B, 10.1302/0301-620X.93B225476, 93 B, 2, 184-187, 2011.02, In order to investigate the mechanisms of collapse in osteonecrosis of the femoral head, we examined which part of the femoral head was the key point of a collapse and whether a collapsed region was associated with the size of the necrotic lesion. Using 30 consecutive surgically removed femoral heads we retrospectively analysed whole serial cut sections, specimen photographs, specimen radiographs and histological sections. In all of the femoral heads, collapse consistently involved a fracture at the lateral boundary of the necrotic lesion. Histologically, the fractures occurred at the junction between the thickened trabeculae of the reparative zone and the necrotic bone trabeculae. When the medial boundary of the necrotic lesion was located lateral to the fovea of the femoral head, 18 of 19 femoral heads collapsed in the subchondral region. By contrast, when the medial boundary was located medial to the fovea, collapse in the subchondral region was observed in four of 11 femoral heads (p = 0.0011). We found that collapse began at the lateral boundary of the necrotic lesion and that the size of the necrotic lesion seemed to contribute to its distribution..
95. Ryosuke Yamaguchi, Takuaki Yamamoto, goro motomura, Satoshi Ikemura, Yukihide Iwamoto, MRI-detected double low-intensity bands in osteonecrosis of the femoral head, Journal of Orthopaedic Science, 10.1007/s00776-011-0059-x, 16, 4, 471-475, 2011.01.
96. Ikemura S, Yamamoto T, Motomura G, Nakashima Y, Mawatari T, Iwamoto Y, MRI evaluation of collapsed femoral heads in patients 60 years old or older: Differentiation of subchondral insufficiency fracture from osteonecrosis of the femoral head, American Journal of Roentgenology, 195, 1, 63-8, 2010.07.
97. Satoshi Ikemura, Takuaki Yamamoto, goro motomura, Yasuharu Nakashima, Taro Mawatari, Yukihide Iwamoto, MRI evaluation of collapsed femoral heads in patients 60 years old or older
Differentiation of subchondral insufficiency fracture from osteonecrosis of the femoral head, American Journal of Roentgenology, 10.2214/AJR.09.3271, 195, 1, 2010.07, OBJECTIVE. The purpose of this article is to verify the hypothesis that osteonecrosis and subchondral insufficiency fracture of the femoral head can be differentiated on the basis of their appearance on MRI. SUBJECTS AND METHODS. Between May 1998 and February 2009, we reviewed 30 consecutive hips in 30 patients, 60 years old or older at the time of onset of hip pain, with radiologic evidence of subchondral collapse of the femoral head and with both MR images and histologic results available. Both clinical and radiologic appearances were investigated. The patients were divided into two groups according to the shape of low-intensity bands on T1-weighted images. The first group showed concavity of the articular surface, which is characteristic of osteonecrosis, and the second group showed an irregular convexity of the articular surface, which is characteristic of subchondral insufficiency fracture. RESULTS. Sixteen hips (53.3%) showed evidence of osteonecrosis, and 14 (46.7%) showed evidence of subchondral insufficiency fracture, which was consistent with the corresponding histopathologic diagnoses. In all cases of osteonecrosis, the patient had a history of either corticosteroid intake or alcohol abuse. Among patients with subchondral insufficiency fracture, the proportion of women was significantly higher than that among patients with osteonecrosis. A crescent sign (subchondral fracture) was present radiographically in about half of all cases in both groups. CONCLUSION. The results of the present study suggest that the shape of the low-intensity band on MRI is useful for the differentiating subchondral insufficiency fracture from osteonecrosis. In addition, among osteoporotic elderly women without any history of corticosteroid intake or alcohol abuse, a diagnosis of subchondral insufficiency fracture should be considered..
98. Goro Motomura,Takuaki Yamamoto,Kenya Suenaga,Yasuharu Nakashima,Taro Mawatari,Satoshi Ikemura, Yukihide Iwamoto, MD., Ph.D. , Long-term Outcome of Transtrochanteric Anterior Rotational Osteotomy for Osteonecrosis of the Femoral Head in Patients with Systemic Lupus Erythematosus
, Lupus, 2010.06.
99. goro motomura, T. Yamamoto, K. Suenaga, Yasuharu Nakashima, T. Mawatari, Satoshi Ikemura, Y. Iwamoto, Long-term outcome of transtrochanteric anterior rotational osteotomy for osteonecrosis of the femoral head in patients with systemic lupus erythematosus, Lupus, 10.1177/0961203310361896, 19, 7, 860-865, 2010.06, This study sought to examine the long-term outcomes of transtrochanteric anterior rotational osteotomy (ARO) as treatment for osteonecrosis of the femoral head (ONFH) in patients with systemic lupus erythematosus (SLE). Twenty-one patients (33 hips), aged 20-40 years, underwent ARO between 1980 and 1988. We examined 16 patients (25 hips), a 76% follow-up rate. A Kaplan-Meier curve was used for survivorship analysis. Patients with surviving hips were evaluated by the modified Oxford hip score and Short Form 36 (SF-36). Twelve hips in eight patients had survived at the final follow-up. The average length of hip survival was 24.6 years (range: 20.1-27.2 years). Three patients (six hips) had died of unrelated causes without any subsequent operation. Based on Kaplan-Meier analysis with the endpoint defined as the need for a subsequent operation, the hip survival rate at 25 years was 73.7% (95% confidence interval, ±19.8%). Based on classification by the modified Oxford hip score, five hips were classified as excellent, two hips were good, and the remaining five hips were fair. The average SF-36 summary score for the physical and mental components was 38.7 and 47.2 points, respectively. The physical component summary scores for three patients exceeded the normal level of the Japanese population..
100. G. Zhao, T. Yamamoto, Satoshi Ikemura, goro motomura, T. Mawatari, Yasuharu Nakashima, Y. Iwamoto, Radiological outcome analysis of transtrochanteric curved varus osteotomy for osteonecrosis of the femoral head at a mean follow-up of 12.4 years, Journal of Bone and Joint Surgery - Series B, 10.1302/0301-620X.92B6.23621, 92, 6, 781-786, 2010.06, We investigated the factors related to the radiological outcome of a transtrochanteric curved varus osteotomy in patients with osteonecrosis of the hip. We reviewed 73 hips in 62 patients with a mean follow-up of 12.4 years (5 to 31.1). There were 28 men and 34 women, with a mean age of 33.3 years (15 to 68) at the time of surgery. The 73 hips were divided into two groups according to their radiological findings: group 1 showed progression of collapse and/or joint-space narrowing; group 2 had neither progressive collapse nor joint-space narrowing. Both of these factors and the radiological outcomes were analysed by a stepwise discriminant analysis. A total of 12 hips were categorised as group 1 and 61 as group 2. Both the post-operative intact ratio and the localisation of the necrotic lesion correlated with the radiological outcome. The cut-off point of the postoperative intact ratio to prevent the progression of collapse was 33.6%, and the cut-off point to prevent both the progression of collapse and joint-space narrowing was 41.9%. The results of this study indicate that a post-operative intact ratio of 33.0% is necessary if a satisfactory outcome is to be achieved after this varus osteotomy..
101. Masanori Fujii, Yasuharu Nakashima, Takuaki Yamamoto, Taro Mawatari, goro motomura, Akinobu Matsushita, Shuichi Matsuda, Seiya Jingushi, Yukihide Iwamoto, Acetabular retroversion in developmental dysplasia of the hip, Journal of Bone and Joint Surgery - Series A, 10.2106/JBJS.I.00046, 92, 4, 895-903, 2010.04, Background: Patients with developmental dysplasia of the hip are prone to the development of degenerative changes in the affected hip. The aim of this study was to evaluate the prevalence, morphological features, and clinical relevance of acetabular retroversion in these patients. Methods: We investigated the version and morphological features of the acetabulum using pelvic radiographs and computed tomography images of ninety-six hips in fifty-nine patients with developmental dysplasia of the hip. A diagnosis of acetabular retroversion was based on the presence of a positive cross-over sign on the pelvic radiograph. Using computed tomography images, we determined the acetabular anteversion angle at various levels in the axial plane. The acetabular sector angle served as an indicator of acetabular coverage of the femoral head. We evaluated the association between acetabular version and the patient's age at the onset of pain. Fifty normal hips were examined as controls. Results: Weobserved acetabular retroversion in 18% (seventeen) of the ninety-six hips in the patients with developmental dysplasia of the hip. The mean acetabular anteversion angle in the hips with acetabular retroversion was significantly smaller, at all levels, than that in the hips with acetabular anteversion; this tendency was more evident at proximal levels. There was significantly less posterior and posterosuperior coverage in the hips with acetabular retroversion than in those with acetabular anteversion, but superior acetabular coverage did not differ between the groups. Multivariate analysis showed that the onset of pain occurred at a significantly earlier age in patients with acetabular retroversion (27.9 years) than in those with acetabular anteversion (40.5 years), regardless of the severity of the dysplasia (p = 0.003). Conclusions: In patients with developmental dysplasia of the hip, acetabular retroversion results from relatively deficient coverage by the posterior portion of the acetabulum. Developmental dysplasia with acetabular retroversion is associated with an earlier onset of pain than is developmental dysplasia with anteversion, suggesting a correlation between deficiency of the posterior acetabular wall and the earlier onset of pain. Level of Evidence: Prognostic Level IV. See Instructions to Authors for a complete description of levels of evidence..
102. Satoshi Ikemura, Takuaki Yamamoto, Kenjiro Nishida, goro motomura, Yukihide Iwamoto, Gender difference in the development of steroid-induced osteonecrosis in rabbits, Rheumatology, 10.1093/rheumatology/keq044, 49, 6, 1128-1132, 2010.03, Objective: To investigate the incidence of steroid-induced osteonecrosis (ON) among male and female rabbits. Methods: Forty-seven adult rabbits (male, n = 24; female, n = 23) were injected once intramuscularly into the right gluteus medius muscle with 20 mg/kg of methylprednisolone acetate. Haematological examinations were performed just before and at 1 and 2 weeks after the steroid injection. Two weeks after the injection, both femora and humeri were histopathologically examined for the presence of ON, and the bone marrow fat cells were examined morphologically. Results: Sixteen of 24 male rabbits (66.7%) and 5 of 23 female rabbits (21.7%) developed ON. There was a significant difference in the rate of incidence of ON between male and female rabbits (P = 0.0032). Haematologically, at 1 week after the steroid injection, both the mean low-density lipoprotein (LDL) and the ratio of LDL cholesterol to high-density lipoprotein cholesterol in the male rabbits were significantly higher than those in the female rabbits (P = 0.0001 for both comparisons). The bone marrow fat cells of the male rabbits [61.5 (5.6) μm] were significantly larger than those of the female rabbits [58.9 (3.7) μm; P = 0.0102]. Conclusion: This study indicates that gender may be an important factor in considering the pathogenesis of steroid-induced ON..
103. Garida Zhao, Takuaki Yamamoto, Satoshi Ikemura, Yasuharu Nakashima, Taro Mawatari, goro motomura, Yukihide Iwamoto, A histopathological evaluation of a concave-shaped low-intensity band on T1-weighted MR images in a subchondral insufficiency fracture of the femoral head, Skeletal Radiology, 10.1007/s00256-009-0750-6, 39, 2, 185-188, 2010.02, A 73-year-old female suffered from right hip pain without any history of antecedent trauma. The initial radiograph showed a slight narrowing of the joint space in the right hip. The patient was treated by non-weight bearing for 5 weeks. Radiographs obtained 3 months after the onset of pain showed the progression of both the joint-space narrowing and subchondral collapse at the superior portion. T1-weighted MR (magnetic resonance) images obtained 3 months after the onset revealed an irregular-shaped lowintensity area just beneath the articular cartilage as well as a low-intensity band, which was concave to the articular surface. A total hip replacement was performed. A histopathological examination revealed fracture callus and granulation tissue in the subchondral area. This subchondral fractured area was surrounded by vascular rich granulation tissue and fibrous tissue, which corresponded to the concave-shaped low-intensity band observed on the T1- weighted image..
104. Kenyu Iwasaki, Takuaki Yamamoto, Yasuharu Nakashima, Taro Mawatari, goro motomura, Satoshi Ikemura, Yukihide Iwamoto, Subchondral insufficiency fracture of the femoral head after liver transplantation, Skeletal Radiology, 10.1007/s00256-009-0706-x, 38, 9, 925-928, 2009.09, A 53-year-old woman developed a subchondral insufficiency fracture of the right femoral head after undergoing a liver transplantation. Radiographs obtained at her first visit demonstrated a slight subchondral collapse in the superolateral portion of the femoral head. Magnetic resonance imaging (MRI) disclosed an irregular, discontinuous, low-intensity band on the T1-weighted image. After 7 months of conservative treatment, the hip pain and the radiograph abnormalities had both disappeared. On the follow-up T1-weighted MR image obtained 17 months after the onset, the band of low signal intensity was not obvious. A subchondral insufficiency fracture is one of the diagnoses to be considered in patients presenting with hip pain after a liver transplantation..
105. Satoshi Ikemura, Takuaki Yamamoto, Yasuharu Nakashima, Taro Mawatari, goro motomura, Yukihide Iwamoto, Transtrochanteric anterior rotational osteotomy for osteonecrosis of the femoral head in patients 20 years or younger, Journal of Pediatric Orthopaedics, 10.1097/BPO.0b013e31819bc746, 29, 3, 219-223, 2009.04, BACKGROUND:: For young patients with osteonecrosis of the femoral head, especially those younger than 20 years, a joint-preserving operation may be one of the surgical treatment options to be considered. We investigated the clinical and radiological results of transtrochanteric anterior rotational osteotomy for the treatment of osteonecrosis of the femoral head in patients 20 years or younger. METHODS:: Between 1976 and 2001, a transtrochanteric anterior rotational osteotomy was performed in 28 hips of 23 patients aged 20years or younger with osteonecrosis of the femoral head. Among them, 27 hips of 22 patients with a minimum follow-up duration of 2years were investigated (follow-up rate, 96.4%). They included 7males and 15 females with a mean age of 16 years at the time of surgery. The mean follow-up period was 14.7 years (range, 2.0-31.7 years). The clinical assessment was made based on the Merle d'Aubigné-Postel score. The postoperative intact ratio, joint-space narrowing, and progression of collapse were all investigated radiographically. RESULTS:: Two (7.4%) of the 27 hips required total hip arthroplasty because of restrictions in the range of motion, whereas the original hip joints in 25 (92.6%) of the 27 hips were preserved at the time of final follow-up. The mean preoperative Merle d'Aubigné-Postel score was 10.4 points, which improved to 15.9 points at the final follow-up (P < 0.0001). The mean postoperative intact ratio was 49.8% (range, 30-100). Five (18.5%) of the 27 hips had a progressive joint-space narrowing, but progression of the collapse was not observed in anyhips. CONCLUSIONS:: Transtrochanteric anterior rotational osteotomy appears to be a useful joint-preserving operation for patients younger than 20years..
106. goro motomura, Takuaki Yamamoto, Takahiko Irisa, Keita Miyanishi, Kenjiro Nishida, Yukihide Iwamoto, Dose effects of corticosteroids on the development of osteonecrosis in rabbits, Journal of Rheumatology, 10.3899/jrheum.080324, 35, 12, 2395-2399, 2008.12, Objective. The relationship between dose of corticosteroids and the prevalence of osteonecrosis (ON) has not been established. We examined the dose effects of corticosteroids on the development of ON in a rabbit model. Methods. Rabbits were injected once intramuscularly with 1 (12 rabbits), 5 (12 rabbits), 20 (20 rabbits), and 40 (25 rabbits) mg/kg of methylprednisolone acetate (MPSL) into the right gluteus medius muscle. Four weeks after the MPSL injection, the proximal and distal parts of both the femora and humeri were histopathologically examined for the presence of ON. Hematological examinations were performed before and after the corticosteroid injection. Results. In rabbits with 1, 5, 20, and 40 mg/kg MPSL, the incidence of ON was 0, 42%, 70%, and 96%, respectively. The dose of MPSL showed a significant association with the incidence of ON. Histologically, reparative tissues around the ON sites were observed in the rabbits with 5 mg/kg MPSL, but not observed in rabbits with 20 and 40 mg/kg MPSL. On hematological examination, hyperlipidemia and thrombocytopenia were most apparent in the rabbits receiving 40 mg/kg MPSL. Conclusion. The study suggested that the dose of corticosteroids plays an important role in the development of ON in rabbits. The repair process was also found to be influenced by the dose of corticosteroids. Corticosteroid-induced hyperlipidemia and thrombocytopenia seemed to be associated with the incidence of ON..
107. goro motomura, Takuaki Yamamoto, Keita Miyanishi, Kyoko Kondo, Yoshio Hirota, Yukihide Iwamoto, Risk factors for developing osteonecrosis after prophylaxis in steroid-treated rabbits, Journal of Rheumatology, 10.3899/jrheum.080416, 35, 12, 2391-2394, 2008.12, Objective. Both abnormal lipid metabolisms and coagulopathy have been suggested to be associated with the development of steroid-induced osteonecrosis (ON). We examined plasma risk factors for development of steroid-induced ON in rabbits after prophylaxis with a lipid-lowering agent and/or an anticoagulant. Methods. Seventy adult male rabbits were injected intramuscularly once with 20 mg/kg methylprednisolone acetate. Fifty-five rabbits received prophylaxis with probucol (a lipid-lowering agent; n = 20) or warfarin (an anticoagulant; n = 14) or both (n = 21). Probucol and warfarin were administered beginning 1 to 2 weeks prior to steroid injection. Two weeks after steroid injection, the bilateral femora and humeri were examined histopathologically for the presence of ON. Based on a logistic regression model, laboratory variables before steroid injection were assessed to determine whether they demonstrated any association with the risk of ON. Results. Twenty-one rabbits developed ON. In the univariate analyses, significant positive associations were observed between plasma concentrations of triglyceride and low-density lipoprotein and the risk of development of ON. In the multivariate model, only the plasma triglyceride level suggested a positive association. Even after adjusting for probucol and warfarin use, the plasma triglyceride level was still suggested to be a predictor for development of ON. Rabbits with higher baseline triglyceride levels had a more pronounced triglyceride increase in their response to steroids. Conclusion. Our study suggests that, after prophylaxis with probucol and/or warfarin, plasma triglyceride level is associated with the development of steroid-induced ON in rabbits..
108. Keita Miyanishi, Takuaki Yamamoto, Takahiko Irisa, Akihisa Yamashita, goro motomura, Seiya Jingushi, Yukihide Iwamoto, Effects of tacrolimus (FK506) on the development of osteonecrosis in a rabbit model, Immunopharmacology and Immunotoxicology, 10.1080/08923970701812647, 30, 1, 79-90, 2008.03, The present study examined the effects of tacrolimus (FK506) on the development of osteonecrosis in rabbits. In Experiment A, rabbits were given FK506, and also given a single dose of steroid. Control rabbits were given the same dose of steroid only. In Experiment B, rabbits were given FK506 and a reduced dose of steroid. The results showed that addition of FK506 did not change the number of rabbits with osteonecrosis when an identical steroid dose was given. When the steroid dose was reduced, the osteonecrosis incidence significantly decreased (p < 0.01). These results suggest that the clinically reported decrease in the osteonecrosis incidence following the introduction of FK506 is most likely attributable to the lower doses of steroids..
109. Kenjiro Nishida, Takuaki Yamamoto, goro motomura, Seiya Jingushi, Yukihide Iwamoto, Pitavastatin may reduce risk of steroid-induced osteonecrosis in rabbits
A preliminary histological study, Clinical orthopaedics and related research, 10.1007/s11999-008-0189-4, 466, 5, 1054-1058, 2008.01, Several animal and human studies suggest pharmacological approaches may prevent steroid-induced osteonecrosis (ON). We asked whether the newly developed 3-hydroxymethyl-3-glutaryl-CoA (HMG-CoA) reductase inhibitor, pitavastatin, could prevent steroid-induced ON in rabbits. We injected 65 adult male Japanese white rabbits once with 20 mg/kg of methylprednisolone acetate into the right gluteus medius muscle. The rabbits were divided into two groups; one group of 35 rabbits received pitavastatins (PS), and the other group of 30 rabbits received no prophylaxis (CTR). Hematological examinations were performed just before the steroid injection (0 weeks) and at 1 and 2 weeks after steroid injection; both the femora and the humeri were histologically examined 2 weeks postinjection. The incidence of histologic changes consistent with early ON in the PS group (13 of 35; 37%) was lower in comparison to the CTR group (21 of 30; 70%). The size of the bone marrow fat cells in the PS group (56.6 ± 10 μm) was smaller than those in the CTR group (60 ± 4 μm). The data suggest pitavastatin has the potential to lower the incidence of steroid-induced ON in rabbits..
110. Takuaki Yamamoto, Keita Miyanishi, goro motomura, Kenjiro Nishida, Yukihide Iwamoto, Katsuo Sueishi, Animal models for steroid-induced osteonecrosis, Clinical calcium, 17, 6, 879-886, 2007.01, We describe that high-dose methylprednisolone (20 mg/kg) can induce multifocal osteonecrosis (ON) in conjunction with thrombocytopenia, hypofibrinogenemia, and hyperlipemia. Detailed clinical and laboratory evaluations of coagulation system are recommended in those patients who develop manifestations of an abnormal lipid metabolism shortly after high-dose corticosteroid therapy. Moreover, we investigated the effects of the combination treatment with an anticoagulant (warfarin) plus a lipid-lowering agent (probucol) on prevention of steroid-induced osteonecrosis (ON) in this animal model. The incidence of ON in warfarin plus probucol (5%) was significantly lower than that observed in the control group (70%) (p <0.0001). Our results experimentally showed that the combined use of an anticoagulant and a lipid-lowering agent helps prevent steroid-induced ON in rabbits..
111. Keita Miyanishi, Takuaki Yamamoto, Takahiko Irisa, Akihisa Yamashita, goro motomura, Seiya Jingushi, Yukihide Iwamoto, Effects of cyclosporin A on the development of osteonecrosis in rabbits, Acta Orthopaedica, 10.1080/17453670610013042, 77, 5, 813-819, 2006.10, Background: Osteonecrosis (ON) of the femoral head is a serious complication in patients who have undergone organ transplantation. Introduction of cyclosporin A has resulted in lower-dosage steroid treatment and a decrease in the occurrence of ON. We examined the effect of cyclosporin A on the development of ON in rabbits. Methods: In experiment A, rabbits were given cyclosporin A and 20 mg/kg methylprednisolone acetate. The control group was given 20 mg/kg methylprednisolone acetate only. Experiment B was then performed to mimic the clinical situation in which the use of cyclosporin A and lower steroid doses resulted in a decrease in occurrence of ON. In Experiment C, the effects of treatment with cyclosporin A only on development of ON were examined. 4 weeks after injection, bilateral femora and humeri were examined histopathologically for ON. Results: Cyclosporin A increased the incidence of ON in rabbits when given in combination with steroid (p = 0.04). No ON lesions were observed in rabbits treated with cyclosporin A alone. Interpretation: Our findings suggest that the clinically reported reduction in occurrence of ON following the use of cyclosporin A is probably attributable to the lower steroid doses used. Copyright.
112. goro motomura, Takuaki Yamamoto, Yasuharu Nakashima, Toshihide Shuto, Seiya Jingushi, Yukihide Iwamoto, Outcome of the Contralateral Hip in Rapidly Destructive Arthrosis After Total Hip Arthroplasty. A Preliminary Report, Journal of Arthroplasty, 10.1016/j.arth.2005.08.007, 21, 7, 1026-1031, 2006.10, We investigated the outcome of the contralateral hip in patients with rapidly destructive arthrosis of the hip after total hip arthroplasty. Twenty-four patients were included, and the mean duration of radiographic follow-up was 7.0 years (range, 3.8-17.8 years). To assess the capable parameters for predicting the development of osteoarthritis, we evaluated the receiver operating characteristic curves. Three (12.5%) of 24 patients developed osteoarthritis and underwent total hip arthroplasty within 3.8 to 6.5 years. In these 3 patients, both the acetabular-head index and the center-edge angle were significantly lower than those in patients without osteoarthritis (P < .005). Based on the receiver operating characteristic curves, both an acetabular-head index of less than 72% and a center-edge angle of less than 16° were considered to be associated with the development of osteoarthritis..
113. Kenjiro Nishida, Takuaki Yamamoto, goro motomura, Toshihide Shuto, Yasuharu Nakashima, Seiya Jingushi, Yukihide Iwamoto, Early MRI findings of the acetabulum and femoral head in a dysplastic hip resulting in a rapid destruction of the hip joint, Archives of Orthopaedic and Trauma Surgery, 10.1007/s00402-005-0053-x, 125, 8, 567-570, 2005.10, We documented a case of rapidly destructive arthrosis of the hip joint (RDA), in whom abnormal findings were observed not only in the femoral head but also in the acetabulum on magnetic resonance images (MRI) in the early stage. Radiographs made 1 month after the onset of pain showed a slight narrowing of the joint space. MRI obtained 2 months after the onset detected small foci of low signal intensity in the subchondral area of the femoral head on the T1-weighted images, and a linear pattern of high signal intensity in the lateral side of the acetabulum on the T2-weighted images. During the 17-month follow-up period, this case eventually underwent massive destruction of the femoral head as well as the acetabulum..
114. K. Miyanishi, T. Yamamoto, T. Irisa, goro motomura, S. Jingushi, K. Sueishi, Y. Iwamoto, Effects of different corticosteroids on the development of osteonecrosis in rabbits, Rheumatology, 10.1093/rheumatology/keh505, 44, 3, 332-336, 2005.03, Objectives. Osteonecrosis (ON) of the femoral head is a devastating complication occurring in patients receiving corticosteroid treatment. This study examined the effect of three corticosteroids on the development of ON in rabbits. Methods. Thirty-nine rabbits were injected once intramuscularly with either 25 mg/kg prednisolone sodium succinate (PSL; 13 rabbits), 20 mg/kg methylprednisolone acetate (MPSL; 13 rabbits) or 20 mg/kg triamcinolone acetonide (TR; 13 rabbits). Four weeks after corticosteroid injection, the bilateral femora and humeri were examined histopathologically for the presence of ON. Haematological examinations were performed before and after corticosteroid injection. Results. MPSL treatment (17/26 proximal femora, 65%) significantly increased ON incidence in the proximal femora compared with the levels seen after TR (4/26, 15%) or PSL (3/26, 12%) treatment (P < 0.01). Although not significantly increased in comparison with rabbits receiving PSL treatment (1/26 proximal humeri, 4%), ON incidence within the proximal humeri was significantly increased in MPSL-treated rabbits (6/26, 23%) in comparison with those seen in rabbits receiving TR (0/26, 0%) treatment (P < 0.05). Serum levels of cholesterol, triglyceride and free fatty acid were significantly higher 1, 2 and 4 weeks after corticosteroid treatment in rabbits treated with MPSL relative to rabbits receiving TR and rabbits with PSL treatment (P < 0.05). Conclusions. MPSL treatment significantly increased ON incidence in rabbits over levels seen after TR or PSL treatment..
115. goro motomura, Takuaki Yamamoto, Keita Miyanishi, Akihisa Yamashita, Katsuo Sueishi, Yukihide Iwamoto, Bone marrow fat-cell enlargement in early steroid-induced osteonecrosis - A histomorphometric study of autopsy cases, Pathology Research and Practice, 10.1016/j.prp.2004.10.003, 200, 11-12, 807-811, 2005.02, Some animal studies and magnetic resonance imaging studies suggest that there may exist a relationship between abnormal lipid metabolisms and osteonecrosis. The purpose of this study was to examine the size of bone marrow fat cells in the early osteonecrosis femoral head using autopsy specimens. We compared the size of bone marrow fat cells in the viable areas in the following three autopsy groups: the early osteonecrosis group (4 femoral heads); the steroid-administered group (without osteonecrosis) (n = 10), and the normal group (n = 19). In addition, after adjusting for age and sex, the size of bone marrow fat cells was compared using multiple regression analysis. The size of bone marrow fat cells was significantly larger in the early osteonecrosis group (84.7±5.5 μm) than in both the steroid-administered group (75.3±4.3 μm) and the normal group (76.3±4.9 μm) (p < 0.01 and p < 0.05, respectively). After adjusting for age and sex, the size of bone marrow fat cells in the early osteonecrosis group was significantly larger as compared with the other groups. This study suggests that in steroid-induced osteonecrosis, the size of bone marrow fat cells increases significantly at an early stage..
116. goro motomura, Takuaki Yamamoto, Keita Miyanishi, Seiya Jingushi, Yukihide Iwamoto, Combined effects of an anticoagulant and a lipid-lowering agent on the prevention of steroid-induced osteonecrosis in rabbits, Arthritis and Rheumatism, 10.1002/art.20517, 50, 10, 3387-3391, 2004.10, Objective. To investigate the effects of combination treatment with an anticoagulant (warfarin) plus a lipid-lowering agent (probucol) on the prevention of steroid-induced osteonecrosis (ON) in rabbits. Methods. Adult male Japanese white rabbits were injected once intramuscularly with 20 mg/kg of methylprednisolone acetate into the right gluteus medius muscle. The rabbits were then divided into 4 groups and treated as follows: one group received warfarin plus probucol (WP; n = 25), one received probucol alone (PA; n = 30), one received warfarin alone (WA; n = 26), and one received no treatment (nonprophylactic [NP]; n = 20). Two weeks after the steroid injection, the femora anil humeri were examined hisiopathologically for the presence of ON. The sizes of the bone marrow fat cells were examined morphologically. Hmatologic examinations were performed before and after the steroid injection. Results. The incidence of ON in the WP group (5%) was significantly lower than that observed in the NP group (70%). While the incidence rates of ON in the PA (38%) and WA (33%) groups were also significantly lower than that in the NP group, they were significantly higher than that observed in the WP group. The sizes of the bone marrow fat cells in both the WP (53.5 ± 4.1 μm) and the PA (52.0 ± 5.0 μm) groups were significantly smaller than those in the NP group (60.0 ± 4.0 μm). We also observed a prolongation of the prothrombin time and a reduction in the plasma lipid levels in the WP group during the study. Conclusion. This study experimentally confirmed that the combined use of an anticoagulant and a lipid-lowering agent helps prevent steroid-induced ON in rabbits..
117. T. N. Board, goro motomura, Takuaki Yamamoto, Keita Miyanishi, Kenzo Shirasawa, Yasuo Noguchi, Yukihide Iwamoto, Subchondral insufficiency fracture of the femoral head and acetabulum
Indications for total hip arthroplasty [5] (multiple letters), Journal of Bone and Joint Surgery - Series A, 10.2106/00004623-200303000-00036, 85, 3, 2003.03.
118. goro motomura, Takuaki Yamamoto, Keita Miyanishi, Kenzo Shirasawa, Yasuo Noguchi, Yukihide Iwamoto, Subchondral insufficiency fracture of the femoral head and acetabulum
A case report, Journal of Bone and Joint Surgery - Series A, 10.2106/00004623-200207000-00018, 84, 7, 1205-1209, 2002.01.