Yukihide Iwamoto

Kyushu University, Hukuoka, Fukuoka, Japan

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Publications (750)1873.07 Total impact

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    ABSTRACT: Despite recent advancements in rheumatoid arthritis (RA) pharmacotherapy, surgeons still encounter severely damaged knees. The purpose of the present study was to analyze the mid-term clinical results of total knee arthroplasty (TKA) with metal block augmentation and stem extension. A total of 26 knees in 21 patients who underwent primary TKA with metal block augmentation and stem extension were retrospectively reviewed. All patients with a mean age of 63 years had RA for a mean duration of 15 years. Functional and radiographic results as well as complications were evaluated at the mean follow-up period of 6 years after TKA. Eight knees were lost follow-up after the two-year evaluation. Tibial bone defects with average depth of 19 mm were preoperatively recognized in all 26 knees. The postoperative joint line was reconstructed on average 11 mm above the fibular head using average thickness of 11 mm tibial inserts and 9 mm metal blocks with stem extension. Significant improvements (p < 0.05 for all comparisons) were observed postoperatively in maximum extension angle from -10° to -1°, range of motion from 101 ° to 115 °, and Knee Society Score (knee score/function score) from 35/18 to 90/64. Non-progressive radiolucent lines beneath the metal block and osteosclerotic changes around the medullary stem were found in 16 knees (62 %) and 14 knees (54 %), respectively. There was two failures (8 %): fragile supracondylar femur fractures and knee instability. No knees showed any radiographic implant loosening, dislocation, polyethylene insert breakage, peroneal palsy, or infection. Primary TKA with metal block augmentation and stem extension could effectively restore function in RA patients with advanced forms of knee joint destruction, and be reliable and durable for a mean postoperative period of 6 years. Further study is needed to determine the long-term results of TKA using metal block augmentation and stem extension.
    BMC Musculoskeletal Disorders 12/2015; 16(1). DOI:10.1186/s12891-015-0689-9 · 1.72 Impact Factor
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    ABSTRACT: CCAAT/enhancer-binding protein β (C/EBPβ) is a transcription factor that is activated in the synovium in rheumatoid arthritis (RA) and promotes expression of various matrix metalloproteinases. In this study, we examined whether C/EBPβ mediates the expression of receptor activator of nuclear factor-kappa-B ligand (RANKL) and drives osteoclast formation in primary fibroblast-like synoviocytes (FLS) from RA patients. The cooperation of C/EBPβ and activation transcription factor-4 (ATF4) in the regulation of the RANKL promoter was also investigated. Immunofluorescence staining was performed for C/EBPβ, RANKL, and ATF4 in synovium from RA patients. Adenovirus expression vectors for two major isoforms, C/EBPβ-liver-enriched activator protein (LAP) and - liver-enriched inhibitory protein (LIP), or small interfering RNA for C/EBPβ, were used to manipulate C/EBPβ expression in RA-FLS. RA-FLS over-expressing C/EBPβ were co-cultured with peripheral blood mononuclear cells (PBMCs) to test osteoclast formation by tartrate-resistant acid phosphatase (TRAP) staining. A promoter assay for RANKL, a chromatin immunoprecipitation (ChIP) assay and an immunoprecipitation (IP) assay were also performed. Immunofluorescence staining showed colocalization of C/EBPβ, ATF4 and RANKL in RA synovium. Western blotting revealed the expression of C/EBPβ-LAP and -LIP in RA-FLS. Over-expression of either C/EBPβ-LAP or -LIP significantly increased the expression of RANKL mRNA, while C/EBPβ-LIP down-regulated osteoprotegerin (OPG) mRNA. The RANKL/OPG mRNA ratio was significantly increased by C/EBPβ-LIP over-expression. Knockdown of C/EBPβ with siRNA decreased the expression of RANKL mRNA. The number of TRAP-positive multinucleated cells was increased in co-cultures of PBMCs and FLS over-expressing either C/EBPβ-LAP or -LIP, but was more significant with LIP. C/EBPβ-LIP does not have a transactivation domain. However, promoter assays showed that C/EBPβ-LIP and ATF4 synergistically transactivate the RANKL promoter. ChIP and IP assays revealed the cooperative binding of C/EBPβ and ATF4 on the RANKL promoter. We demonstrated that C/EBPβ, especially C/EBPβ-LIP in cooperation with ATF4, is involved in osteoclast formation by regulating RANKL expression in RA-FLS. These findings suggest that C/EBPβ plays a crucial role in bone destruction in RA joints.
    Arthritis Research & Therapy 12/2015; 17(1). DOI:10.1186/s13075-015-0532-6 · 3.75 Impact Factor
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    ABSTRACT: In patients with degenerative meniscal tears, subclinical cartilage degeneration may be present even if gross morphological changes are not evident. The aim of this study was to detect occult cartilage degeneration using T1ρ MRI mapping in patients with meniscal tears without obvious radiographic osteoarthritis (OA). A total of 22 subjects with degenerative meniscal tears in the early stages of osteoarthritis [Kellgren-Lawrence (KL) grade of 0-2] and 19 healthy subjects as the control group were examined. The femoral condyle was divided into four 30° wedges (-30°-0° anteriorly, 0°-30°, 30°-60° and 60°-90° posteriorly), and each area of cartilage was further divided into superficial and deep layers of equal thickness. The tibial side was divided into anterior and posterior areas with superficial and deep layers in each. The mean T1ρ values (ms) in each area were calculated. On the femoral side, T1ρ values of the superficial and deep regions (-30°-0°, 0°-30° and 30°-60°) in the meniscal tear group were significantly higher than those in the control group [superficial (-30°-0°): 49.0 ± 4.0 (meniscal tear group) vs 45.1 ± 2.1 (control group), deep (-30°-0°): 45.2 ± 3.3 vs 39.5 ± 5.0, superficial (0°-30°): 54.5 ± 5.3 vs 47.4 ± 5.7, deep (0°-30°): 46.8 ± 4.0 vs 40.7 ± 6.3, superficial (30°-60°): 50.5 ± 3.1 vs 47.1 ± 5.7]. On the tibial side, the meniscal tear group had significantly higher T1ρ values superficially in both anterior and posterior regions compared with the control group [superficial (anterior): 52.0 ± 4.3 vs 46.7 ± 5.4, superficial (posterior): 53.1 ± 5.1 vs 46.0 ± 4.9]. Moreover, these significant differences were observed when comparing patients in the meniscal tear group with KL grades of 0 or 1 and the control group. Our study suggested that early biochemical changes in cartilage associated with degenerative meniscal tears occur first in the superficial zones in areas of contact during slight flexion. Characterising the early relationship between cartilage degeneration and degenerative meniscal tears using T1ρ MRI mapping may be of clinical benefit and provide further evidence linking meniscal injury to OA.
    BMC Musculoskeletal Disorders 12/2015; 16(1). DOI:10.1186/s12891-015-0487-4 · 1.72 Impact Factor
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    ABSTRACT: 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.
    Bone 09/2015; DOI:10.1016/j.bone.2015.09.009 · 3.97 Impact Factor
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    ABSTRACT: 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.
    Skeletal Radiology 09/2015; DOI:10.1007/s00256-015-2258-6 · 1.51 Impact Factor
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    ABSTRACT: We recently published a paper entitled "Anterior Border of the Tibia as a Landmark for Extramedullary Alignment Guide in Total Knee Arthroplasty for Varus Knees" in J.O.R. (29:919-924, 2011)(1) . The key finding was identifying consistent external bony landmarks that can be used for aligning extramedullary total knee arthroplasty (TKA) instruments with varus knees from an image-based anatomic study. A recent clinical study has also demonstrated the efficacy of the anterior border of the tibia as appropriate landmarks for the placement of extramedullary tibial guides(2) . This article is protected by copyright. All rights reserved.
    Journal of Orthopaedic Research 09/2015; DOI:10.1002/jor.23052 · 2.99 Impact Factor
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    ABSTRACT: 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.
    International Orthopaedics 09/2015; DOI:10.1007/s00264-015-2992-3 · 2.11 Impact Factor
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    ABSTRACT: Objectives: This study was conducted to evaluate the period from symptom onset to diagnosis of ankylosing spondylitis (AS) in Japanese patients and to examine possible reasons for delayed diagnosis. Methods: Seventy-two consecutive patients with AS were studied. Diagnostic delay was defined as the gap between the first spondyloarthropathic symptom and diagnosis of AS according to the modified New York criteria. Results: The mean patient ages at disease onset and diagnosis were 25.6±11.3 and 33.3±13.2 years old, respectively, resulting in diagnostic delay of 6.7 years. The number of medical institutions to which patients were referred before diagnosis was 2.4, and orthopedic surgeons were most commonly visited (62%). Non-specific low back pain or lumbar spondylitis (33%) and degenerative arthritis (28%) were the primary diagnoses preceding that of AS. Absence of articular symptoms significantly correlated with diagnostic delay. The patients with disease onset on Year 2000 or later had significantly shorter periods until diagnosis than those before 2000 (3.6 versus 7.5 years). Conclusions: The present study showed a marked diagnostic delay among Japanese patients with AS. Although it has been improved, continuing medical education focusing on inflammatory back pain in adolescent is required for early diagnosis of AS.
    Modern Rheumatology 09/2015; DOI:10.3109/14397595.2015.1088679 · 2.40 Impact Factor
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    ABSTRACT: 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°∼10.2°), axial: 3.9° (-8.4°∼17°), coronal: 0.9° (-11.9°∼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.
    Modern Rheumatology 09/2015; DOI:10.3109/14397595.2015.1092914 · 2.40 Impact Factor
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    ABSTRACT: Objective: Although much attention is now being paid to the health risks associated with nuclear disasters, reliable information is lacking. We retrospectively evaluated the health effects of living in highly contaminated radioactive areas in Japan. Methods: The health evaluation was conducted in Tamano district, Fukushima prefecture, in 2011 and 2012. The surface deposition density of cesium in Tamano was 600 to 1000 kBq/m2 shortly after the Fukushima nuclear accident. Clinical parameters included body mass index, blood pressure, and laboratory examinations for blood cell counts, glucose levels, and lipid profiles. A screening program for internal and external exposure was also implemented. Results: One hundred fifty-five residents participated in the health evaluation. Significant decreases in average body mass index and blood pressure were observed from 2011 to 2012. Annual internal exposure levels did not exceeded 1 mSv in any participants. The levels of external exposure ranged from 1.3 to 4.3 mSv/y measured in the first test period but decreased to 0.8 to 3.6 mSv/y in the second test period. Conclusions: These findings suggest that inhabiting nuclear contaminated areas is not always associated with short-term health deterioration and that radiation exposure can be controlled within safety limitations. (Disaster Med Public Health Preparedness. 2015;0:1-4).
    Disaster Medicine and Public Health Preparedness 09/2015; DOI:10.1017/dmp.2015.102 · 0.70 Impact Factor
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    ABSTRACT: To investigate the mismatch between the length at the center and the length on the shortest and longest peripheral sides of the femoral tunnel socket, reamed with the transportal (TP), outside-in (OI), and modified transtibial (TT) techniques, in anterior cruciate ligament (ACL) reconstruction. Femoral tunnel drilling was simulated on 3-dimensional bone models from 40 subjects. The tunnel directions used with the TP, OI, and modified TT techniques were previously described. By use of the resulting angle, a femoral tunnel socket of 9 mm in diameter was drilled from the center of the femoral ACL insertion. The virtual femoral tunnel was extracted, and the length mismatch was measured between the center and the shortest and longest peripheral sides of the tunnel socket. The mean socket length mismatch between the center and the shortest peripheral part of the femoral tunnel socket was 4.2 ± 0.9 mm with the TP technique, 5.2 ± 1.3 mm with the OI technique, and 3.2 ± 0.8 mm with the modified TT technique. The mean socket length mismatch between the center and the longest peripheral part of the femoral tunnel socket was 3.5 ± 0.9 mm with the TP technique, 4.8 ± 1.5 mm with the OI technique, and 3.3 ± 1.2 mm with the modified TT technique. The length mismatch was significantly higher when the tunnel socket was created by the OI technique (P < .01). A length mismatch with the tunnel socket exists after reaming with either the TP, OI, or modified TT technique. In particular, there was a significant increase in length mismatch when the tunnel socket was created by the OI technique, and the length mismatch would easily become greater than 5 mm. The surgeon should recognize this mismatch when it is created and measure the femoral tunnel socket. In anatomic ACL reconstruction, a mismatch between the length at the center and the length at periphery of the femoral tunnel socket occurs, and this is increased particularly when using the OI technique. The discrepancy in tunnel length between its center and its periphery could cause an overestimation of the tunnel length that could result in an error in length during graft preparation. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.
    Arthroscopy The Journal of Arthroscopic and Related Surgery 08/2015; DOI:10.1016/j.arthro.2015.06.026 · 3.21 Impact Factor
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    ABSTRACT: 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.
    Rheumatology International 08/2015; DOI:10.1007/s00296-015-3346-6 · 1.52 Impact Factor
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    ABSTRACT: Few studies have examined dyslipidemia in patients with rheumatoid arthritis (RA), especially in Japanese cohorts. The aims of this study were to investigate the lipid profiles of RA patients, to assess the relationships between lipid profiles and RA activity and treatment, and to elucidate the effects of HMG-CoA reductase inhibitors (statins) in Japanese patients with RA. A multicenter observational study was conducted in 488 patients with RA. Serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) levels, and RA activity as assessed by disease activity score 28 (DAS28), and treatment for RA were analyzed retrospectively. In statin-treated patients, drug efficacy was also analyzed. The prevalence of hyper LDL-C, hyper TG, and hypo HDL-C were 29.3, 24.2, and 10.2 %, respectively, and the overall prevalence of dyslipidemia was 56.5 %. The level of HDL-C was inversely correlated with DAS28. Patients treated with low-dose glucocorticoids showed significantly higher levels of HDL-C and lower TC/HDL-C ratios compared with patients not receiving glucocorticoid treatment. Conversely, patients treated with biologic agents showed significantly higher levels of LDL-C, lower levels of HDL-C, and higher TC/HDL-C ratios. Atorvastatin significantly improved lipid profiles after a few months of treatment. The prevalence of dyslipidemia in Japanese patients with RA is higher than that in the non-RA population. Our result suggests that controlling RA disease activity might improve lipid profiles and eventually lower cardiovascular risk. Low-dose atorvastatin was effective for treatment of dyslipidemia in RA patients but had no apparent effect on RA disease activity.
    Clinical Rheumatology 08/2015; DOI:10.1007/s10067-015-3049-0 · 1.77 Impact Factor
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    ABSTRACT: Recently the clinical pathway has progressed with digitalization and the analysis of activity. There are many previous studies on the clinical pathway but not many feed directly into medical practice. We constructed a mind map system that applies the spanning tree. This system can visualize temporal relations in outcome variances, and indicate outcomes that affect long-term hospitalization.
    Studies in health technology and informatics 08/2015; 216:1077.
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    ABSTRACT: Because there have been no standard methods to determine pre-operatively the thickness of resection of the proximal tibia in unicompartmental knee arthroplasty (UKA), information about the relationship between the change of limb alignment and the joint line elevation would be useful for pre-operative planning. The purpose of this study was to clarify the correlation between the change of limb alignment and the change of joint line height at the medial compartment after UKA. A consecutive series of 42 medial UKAs was reviewed retrospectively. These patients were assessed radiographically both pre- and post-operatively with standing anteroposterior radiographs. The thickness of bone resection at the proximal tibia and the distal femur was measured radiographically. The relationship between the change of femorotibial angle (δFTA) and the change of joint line height, was analysed. The mean pre- and post-operative FTA was 180.5° (172.2° to 184.8°) and 175.0° (168.5° to 178.9°), respectively. The mean δFTA was 5.5° (2.3° to 10.1°). The joint line elevation of the tibia (JLET) was 4.4 mm (2.1 to 7.8). The δFTA was correlated with the JLET (correlation coefficient 0.494, p = 0.0009). This study indicated that there is a significant correlation between the change of limb alignment and joint line elevation. This observation suggests that it is possible to know the requirement of elevation of the joint line to obtain the desired correction of limb alignment, and to predict the requirement of bone resection of the proximal tibia pre-operatively. Cite this article: Bone Joint Res 2015;4:128-133. ©2015 Okazaki et al.
    08/2015; 4(8):128-33. DOI:10.1302/2046-3758.48.2000416
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    ABSTRACT: Fracture of the femoral stem in total hip arthroplasty (THA) is a rare complication. We have encountered 2 cases of neck fractures of the femoral stem occurring 9 and 12 years after THA. Morphological and biomechanical analysis were performed to investigate the mechanism of these fractures. A titanium alloy femoral stem having a slot with sharp corners (R = 0.2 mm) at the neck had been implanted in both cases. Fracture surfaces were examined by use of scanning electron microscopy (SEM). Stress concentration was simulated by using a finite element method (FEM) to compare slots with sharp (R = 0.2 mm) and smooth (R = 2 mm) corners. Study of the retrieved stems revealed that neck fractures had occurred at the distal end of the slot in both cases. SEM revealed numerous fine fissures extending from the anterolateral edge, striations on the middle of the fracture surface, and dimples on the posteromedial surface, suggesting that the fractures had occurred from the anterolateral aspect toward the posteromedial aspect because of metallic fatigue. FEM analysis showed that mechanical stress was concentrated at the distal and anterolateral corners of the slot. Under 3500-N loading force, the stress at the sharp corner was 556 MPa, which was approximately twofold that at the smooth corner and exceeded the fatigue strength of titanium alloy. These findings showed that the sharp corner of slot increased stress concentrations at the anterolateral aspect and led to the neck fractures.
    Journal of Orthopaedic Science 07/2015; DOI:10.1007/s00776-015-0745-1 · 0.94 Impact Factor
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    ABSTRACT: Background: When spinal kyphosis increases, the compensatory mechanism activates and the pelvic position changes. Increasing the pelvic tilt, which is the orientation of the pelvis with respect to the femoral head, is known to associate with the clinical symptoms in kyphosis in the aging population. It is often difficult to detect the femoral head on radiographs, limiting the ability to determine the pelvic tilt. Therefore, there is a need to establish another parameter independent of the femoral head which closely correlates with the pelvic tilt. Methods: Eighty-two adult patients with full-length lateral standing spine radiographs were recruited (mean age: 73.0 years). A new parameter, the iliac cortical density line (a component of the arcuate line of the ilium) and the iliac tilt (defined as the angle between the iliac cortical density line and the vertical), was analyzed to determine the correlation with the pelvic tilt. Results: Both the pelvic tilt (PT) and iliac tilt (IT) could be identified in 67 patients, and a significant correlation was observed between the PT and IT (r = 0.86, P < 0.0001). The PT could be estimated using the following formula: PT = IT - 12.9 (in females), PT = IT - 16.7 (in males). Conclusions: The iliac tilt, which can be easily and directly measured using the iliac cortical density line, is a new parameter that can reliably estimate the pelvic tilt even when the femoral head is not detectable on the radiograph.
    Journal of Orthopaedic Surgery and Research 07/2015; 10(1):115. DOI:10.1186/s13018-015-0262-0 · 1.39 Impact Factor
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    ABSTRACT: This study examined the outcomes of applying transtrochanteric rotational osteotomy (TRO) for posttraumatic osteonecrosis of the femoral head (ON). 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. 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. 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 %.
    Archives of Orthopaedic and Trauma Surgery 07/2015; 135(9). DOI:10.1007/s00402-015-2282-y · 1.60 Impact Factor
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    ABSTRACT: Neural stem/progenitor cell (NSPC) transplantation is a promising therapeutic strategy for spinal cord injury (SCI). However, the efficacy of NSPC transplantation on severe SCI is poorly understood. We herein show that NSPC transplantation promotes functional recovery after mild and moderate SCI, but not after severe SCI. In severe SCI mice, there were few remaining host neurons within the range of NSPC engraftment; thus, we examined whether the co-distribution of transplant and host is a contributory factor for functional improvement. A cellular selective analysis using laser microdissection revealed that drug-induced host neuronal ablation considerably decreased the synaptogenic potential of the engrafted NSPCs. Furthermore, following host neuronal ablation, neuronal retrograde tracing showed less propriospinal relay connections bridging the lesion after NSPC transplantation. Our findings suggest that the interactive synaptic reorganization between engrafted NSPCs and spared host neurons is crucial for functional recovery, providing significant insight for establishing therapeutic strategies for severe SCI. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.
    Stem Cell Reports 07/2015; 5(2). DOI:10.1016/j.stemcr.2015.06.004 · 5.37 Impact Factor
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    ABSTRACT: Subchondral insufficiency fracture of the femoral head may be confused with osteonecrosis, mainly because of radiological overlap. SPECT/CT with Tc-99 m hydroxymethylene diphosphonate images in 7 patients with subchondral insufficiency fracture were retrospectively reviewed and compared with those from 11 patients with symptomatic early osteonecrosis. In all of the hips with subchondral insufficiency fracture, SPECT/CT showed increased uptake at the subchondral lesions of the femoral head. On the other hand, in all of the hips with osteonecrosis, absence of uptake was confirmed at the subchondral lesions. SPECT/CT may assist in differentiating subchondral insufficiency fracture from osteonecrosis.
    Clinical nuclear medicine 07/2015; 40(9). DOI:10.1097/RLU.0000000000000886 · 3.93 Impact Factor

Publication Stats

10k Citations
1,873.07 Total Impact Points


  • 1992–2015
    • Kyushu University
      • Department of Orthopaedic Surgery
      Hukuoka, Fukuoka, Japan
  • 2014
    • Saga University
      • Department of Advanced Technology Fusion
      Сага Япония, Saga Prefecture, Japan
  • 2008–2013
    • Osaka City University
      • Graduate School of Medicine
      Ōsaka, Ōsaka, Japan
    • Hospital for Special Surgery
      New York, New York, United States
  • 2011
    • Niigata University
      Niahi-niigata, Niigata, Japan
    • Indiana University-Purdue University Indianapolis
      Indianapolis, Indiana, United States
  • 2001–2009
    • Kyushu Sangyo University
      Hukuoka, Fukuoka, Japan
  • 2001–2007
    • Fukuoka University
      • Department of Orthopaedic Surgery
      Hukuoka, Fukuoka, Japan
  • 2006
    • Okayama University
      • Department of Orthopaedic Surgery
      Okayama, Okayama, Japan
    • National Institute of Allergy and Infectious Diseases
      Maryland, United States
  • 2004
    • National Cancer Center, Japan
      Edo, Tōkyō, Japan
    • Kitakyushu University
      • Faculty of Environmental Engineering
      Kitakyūshū, Fukuoka-ken, Japan
  • 2003
    • Bryn Mawr College
      Bryn Mawr, Pennsylvania, United States