Yukihide Iwamoto

Kyushu University, Hukuoka, Fukuoka, Japan

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Publications (739)1849.21 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 · 1.90 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 · 1.90 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 · 3.19 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 · 1.63 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: 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 · 1.01 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; DOI:10.1007/s00402-015-2282-y · 1.36 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; DOI:10.1016/j.stemcr.2015.06.004 · 5.64 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; DOI:10.1097/RLU.0000000000000886 · 2.86 Impact Factor
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    ABSTRACT: The purpose of our study was to evaluate the accuracy of the tibial bone cut in total knee arthroplasty using the anterior tibial border as a guide compared to using bony and soft tissue landmarks of the ankle joint. The extramedullary alignment guide was set parallel to a line connecting the proximal and distal one-thirds of the anterior border of the tibia while the rotational direction of the distal end of the guide was adjusted to the anteroposterior axis of the proximal tibia. Significant differences were detected in the ideal coronal tibial component angles with improvements from 87.2% to 95.9%. The anterior tibial border was a reliable landmark in total knee arthroplasty in clinical practice, as shown by our previous computer simulation. Copyright © 2015. Published by Elsevier Inc.
    The Journal of arthroplasty 07/2015; DOI:10.1016/j.arth.2015.06.055 · 2.37 Impact Factor
  • Muneaki Masuda · Takayoshi Ueta · Keiichiro Shiba · Yukihide Iwamoto
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    ABSTRACT: Deep venous thrombosis (DVT) in spinal cord injury (SCI) patients is a life-threatening comorbidity. Despite its seriousness, prophylaxis and screening for DVT in SCI patients is still not sophisticated. This study aimed to (i) define the epidemiology and incidence of DVT in acute traumatic cervical SCI in a Japanese population; (ii) determine the best timing for DVT screening; and (iii) determine the optimal D-dimer threshold level for use as an easy and minimally invasive screening tool. A prospective clinical study. Acute traumatic cervical SCI patients who were admitted to our facility within two weeks after injury. Multivariate logistic regression was performed for outcome measure. We enrolled 268 patients (223 men and 45 women), between April 2007 and December 2012. After excluding early drop-out patients, 211 patients remained. Assessment for neurological status and blood chemistry, especially blood coagulation levels (prothrombin time, prothrombin time-international normalized ratio, activated partial thromboplastin time, and serum D-dimer) was performed every week until one month after injury. Ultrasonography was performed for DVT detection every two weeks. This study was funded by The General Insurance Association of Japan, The Japan Labour Health and Welfare Organization, and The Japan Orthopedics and Traumatology Foundation, and there was no conflict of interest. DVTs were detected in 22 patients (10.4% of patients studied). All DVT-positive patients demonstrated severe paralysis classified as C or greater on the ASIA Impairment Scale. Multivariate logistic regression of clinical and laboratory parameters revealed that only the D-dimer level at two weeks after injury was an accurate predictor of DVT formation. The optimal threshold of D-dimer for prediction was determined to be 16 μg/dL. The sensitivity and specificity for detecting DVT were 77.3% and 69.2%, respectively. D-dimer levels may be used to predict the likelihood of DVT development in patients with acute cervical SCI. Furthermore, the optimal timing for screening test by D-dimer is two weeks after injury and optimal threshold level for D-dimer for diagnosing DVT is 16 μg/dL. Such a screening test would be cost-efficient and simple to administer, and could then be followed with additional investigations, such as ultrasonography or venography. Copyright © 2015 Elsevier Inc. All rights reserved.
    The spine journal: official journal of the North American Spine Society 06/2015; DOI:10.1016/j.spinee.2015.06.060 · 2.80 Impact Factor
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    ABSTRACT: Ewing sarcoma (ES) is a small round-cell tumor of the bones and soft tissues. ES frequently causes distant metastases, particularly in the lung and bone, which worsens patient prognosis. Cadherin-11 (Cad-11) is an adhesion molecule that is highly expressed in osteoblasts. Its expression is associated with bone metastases in prostate and breast cancer patients, and is known to occur in ES. Here we investigated the effects of Cad-11 on bone metastases of ES. Human ES cell lines RD-ES, SK-ES-1, SK-N-MC, and TC-71 cells were transduced with lentivirus containing Cad-11 shRNA or control shRNA (ES/Cad-11 and ES/Ctr). RD-ES and TC-71 were infected with a lentivirus luciferase vector. Adhesion assays were performed using these cells and recombinant Cad-11-Fc chimera or mouse osteoblast cell line MC3T3-E1. Cell motility was investigated via wound-healing assay. Intracardiac injection of RD-ES/Cad-11 and RD-ES/Ctr was used to create a mouse model of experimental bone metastasis. The association between Cad-11 expression and bone metastases and clinical prognosis in ES patients was analyzed by immunohistochemistry. We found knockdown of Cad-11 in ES cells resulted in reduced attachment ability and cell motility. In a mouse model of metastasis, RD-ES/Cad-11 cells caused fewer metastases than RD-ES/Ctr cells. The expression of Cad-11 in ES patients was significantly related to bone metastases (P < 0.05, logistic regression) and poorer overall survival (P < 0.05, log-rank test). These findings may explain that Cad-11 in ES cells may be essential for cell adhesion and motility, and is a promising molecular target for patients with ES.
    Clinical and Experimental Metastasis 06/2015; DOI:10.1007/s10585-015-9729-y · 3.73 Impact Factor
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    ABSTRACT: 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.
    Rheumatology International 06/2015; DOI:10.1007/s00296-015-3304-3 · 1.63 Impact Factor
  • Annals of the Rheumatic Diseases 06/2015; 74(Suppl 2):435.1-435. DOI:10.1136/annrheumdis-2015-eular.4283 · 10.38 Impact Factor
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    Yasutaka Tashiro · Ken Okazaki · Yukihide Iwamoto
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    ABSTRACT: We aimed to clarify the distance between the anteromedial (AM) bundle and posterolateral (PL) bundle tunnel-aperture centers by simulating the anatomical femoral tunnel placement during double-bundle anterior cruciate ligament reconstruction using 3-D computer-aided design models of the knee, in order to discuss the risk of tunnel overlap. Relationships between the AM to PL center distance, body height, and sex difference were also analyzed. The positions of the AM and PL tunnel centers were defined based on previous studies using the quadrant method, and were superimposed anatomically onto the 3-D computer-aided design knee models from 68 intact femurs. The distance between the tunnel centers was measured using the 3-D DICOM software package. The correlation between the AM-PL distance and the subject's body height was assessed, and a cutoff height value for a higher risk of overlap of the AM and PL tunnel apertures was identified. The distance between the AM and PL centers was 10.2±0.6 mm in males and 9.4±0.5 mm in females (P<0.01). The AM-PL center distance demonstrated good correlation with body height in both males (r=0.66, P<0.01) and females (r=0.63, P<0.01). When 9 mm was defined as the critical distance between the tunnel centers to preserve a 2 mm bony bridge between the two tunnels, the cutoff value was calculated to be a height of 160 cm in males and 155 cm in females. When AM and PL tunnels were placed anatomically in simulated double-bundle anterior cruciate ligament reconstruction, the distance between the two tunnel centers showed a strong positive correlation with body height. In cases with relatively short stature, the AM and PL tunnel apertures are considered to be at a higher risk of overlap when surgeons choose the double-bundle technique.
    Open Access Journal of Sports Medicine 06/2015; 6:219-24. DOI:10.2147/OAJSM.S80809
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    ABSTRACT: Background Combined anteversion is the sum of femoral and acetabular anteversion and represents their morphological relationship in the axial plane. Few studies have investigated the native combined anteversion in patients with symptomatic dysplastic hips. Questions/purposes We hypothesized the following: (1) dysplastic hips have two distinct populations, which differ from each other and from normal hips in their combined anteversion; and (2) these populations differ clinically in terms of correlation between age of onset of symptoms and amount of anteversion. Methods We measured radiographic parameters by CT of 100 dysplastic hips in 76 patients who were symptomatic enough to undergo periacetabular osteotomy and of 50 normal hips in 44 patients who had CT scans as part of preparation for computer-navigated TKAs; these patients had no visible hip arthritis or dysplasia and no hip symptoms. Dysplastic hips were divided into the anteversion (83 hips) and retroversion groups (17 hips) based on acetabular version. Age at pain onset was determined from their medical charts. Results Combined anteversion in the anteversion group was greater than that in the retroversion and control groups: 47° ± 12°, 30° ± 16°, and 36° ± 9°, respectively. In the anteversion group, combined anteversion (r = −0.49; 95% confidence interval [CI], −0.66 to −0.27; p Conclusions These results suggest that not only lateral coverage of the femoral head, but also axial joint morphology is important for the development of pain in the anteversion group. Optimal combined anteversion should be considered during periacetabular osteotomy. Level of Evidence Level IV, prognostic study.
    Clinical Orthopaedics and Related Research 05/2015; DOI:10.1007/s11999-015-4373-z · 2.88 Impact Factor
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    ABSTRACT: Amyloid deposits are prevalent in osteoarthritis (OA)-affected joints. This study defined the dominant precursor and determined if the deposits affect chondrocyte functions. Amyloid deposition in normal and OA human knee cartilage was determined by Congo red staining. Transthyretin (TTR) in cartilage and synovial fluid was analyzed by immunohistochemistry and western blotting. The effects of recombinant amyloidogenic and non-amyloidogenic TTR variants were tested in human chondrocyte cultures. Normal cartilage from young donors did not contain detectable amyloid deposits but 58% (7/12) of aged normal cartilage and 100% (12/12) of OA cartilage samples showed Congo red staining with green birefringence under polarized light. TTR, located predominantly at the cartilage surfaces, was detected in all OA and a majority of aged, but not young normal cartilage. Chondrocytes and synoviocytes did not contain significant amounts of TTR mRNA. Synovial fluid TTR levels were similar in normal and OA knees. In cultured chondrocytes, only an amyloidogenic TTR variant induced cell death, the expression of proinflammatory cytokines, and extracellular matrix degrading enzymes. The effects of amyloidogenic TTR on gene expression were mediated by in part by Toll-like receptor-4, Receptor for advanced glycation endproducts and p38 MAP kinase. TTR-induced cytotoxicity was inhibited by resveratrol, a plant polyphenol that stabilizes the native tetrameric structure of TTR. The findings are the first to suggest that TTR amyloid deposition contributes to cell and extracellular matrix damage in articular cartilage in human OA and that therapies designed to reduce TTR amyloid formation might be useful. This article is protected by copyright. All rights reserved. © 2015, American College of Rheumatology.
    Arthritis and Rheumatology 05/2015; DOI:10.1002/art.39178
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    ABSTRACT: Background: Patients with anterior cruciate ligament (ACL)-injured knees are at an increased risk of posttraumatic osteoarthritis (OA). OA changes secondary to ACL injuries have many variations, and when and where early cartilage degenerative change begins has not yet been established.
    05/2015; 3(5). DOI:10.1177/2325967115585092

Publication Stats

10k Citations
1,849.21 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
  • 2011
    • Indiana University-Purdue University Indianapolis
      Indianapolis, Indiana, United States
  • 2002–2009
    • Kyushu Sangyo University
      Hukuoka, Fukuoka, Japan
    • National Institutes of Health
      Maryland, United States
  • 2007–2008
    • Hospital for Special Surgery
      • Department of Radiology and Imaging
      New York, New York, United States
  • 2001–2007
    • Fukuoka University
      • Department of Orthopaedic Surgery
      Hukuoka, Fukuoka, Japan
    • Matsuyama Red Cross Hospital
      Matuyama, Ehime, Japan
  • 2006
    • Okayama University
      • Department of Orthopaedic Surgery
      Okayama, Okayama, Japan
    • National Institute of Allergy and Infectious Diseases
      Maryland, United States
  • 2004
    • Kitakyushu University
      • Faculty of Environmental Engineering
      Kitakyūshū, Fukuoka-ken, Japan
    • National Cancer Center, Japan
      Edo, Tōkyō, Japan
  • 2003
    • Bryn Mawr College
      Bryn Mawr, Pennsylvania, United States
    • Kyushu Rosai Hospital
      Kitakyūshū, Fukuoka, Japan