Yasuharu Nakashima

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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(More)
Objective. To review the subchondral changes on MR imaging in transient osteoporosis of the hip (TOH) and to consider the pathophysiology. Design and patients. MR images of 12 hips of 11 consecutive patients with TOH were retrospectively studied. The diagnoses of TOH were confirmed on the basis of previously published criteria, including decreased bone(More)
Spinal cord compression is an extremely serious complication of hereditary multiple exostoses (HME). A case of HME with compression of the cervical spinal cord is reported. Complete recovery following surgery was achieved. A review of the relevant literature revealed 51 previous cases of HME with cord/cauda equina compression. Most patients were under 30(More)
BACKGROUND Although a wide variety of acetabular deformities in developmental dysplasia of the hip (DDH) have been reported, the morphologic features of the entire pelvis in DDH are not well characterized and their correlation with acetabular deformity is unknown. QUESTIONS/PURPOSES We determined whether there was a rotational deformity of the entire(More)
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 patients with developmental dysplasia of the hip (DDH). Using pelvic computed tomography (CT) images of 79 hips in 49 Asian women with DDH and 49 normal hips,(More)
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. We retrospectively reviewed 634 hips in 579 patients with primary cementless THA.(More)
BACKGROUND Loosening of the implant after total joint arthroplasty remains a serious problem. The activation of macrophages by wear debris from implants, mediated by the release of cytokines that elicit bone resorption, may lead to loosening. The purpose of the present study was to elucidate the mechanisms of macrophage activation by titanium particles from(More)
OBJECTIVE It was previously found that Th1 but not Th17 cells were predominant in the joints of rheumatoid arthritis (RA). To verify whether this is a unique feature of CD4 T cells in RA joints, we performed comparative flow cytometric analysis of CD4 T cells in RA and osteoarthritis (OA) joints. METHODS Mononuclear cells were isolated from peripheral(More)
For osteoarthritis hips due to severe acetabular dysplasia such as Crowe type 3 or 4, placement of the socket is a difficult procedure in total hip arthroplasty. Because the acetabular bone stock is poor, suitable location for the socket is very limited with respect to achieving good coverage with the host bone. A 51-year-old woman who had an osteoarthritis(More)
OBJECTIVES This study aimed to evaluate the remission in rheumatoid arthritis (RA) patients treated with tocilizumab (TCZ), based on prospectively registered data in clinical practice. METHODS We studied 114 consecutive RA patients treated with TCZ for an average of 3.5 years. Remission was evaluated by using the EULAR criteria and the new ACR/EULAR(More)