Kinematic change of the meniscus and the tibiofemoral joint space in asymptomatic volunteers using a wide bore 3T closed MRI system.

OBJECTIVES: To evaluate kinematic changes in menisci and tibiofemoral joint spaces in extension and flexion using asymptomatic volunteers using a wide-bore 3-T closed MRI system. METHODS: Twenty-two knees from asymptomatic volunteers were examined in knee extension and flexion using a 3-T MRI (sagittal 2D FSE T2-weighted sequence and sagittal 3D isotropic FSE proton density-weighted cube sequence). The meniscal positions, meniscal floating and flounce were evaluated. The widths of the medial and lateral tibiofemoral joint spaces and coronal tibiofemoral angles were measured. RESULTS: In the anteroposterior direction, meniscal extrusion was most frequently seen in the anterior horn of the medial menisci (100%) in extensions (maximum 6.04 mm). Most of the menisci moved significantly to the posterior side from extension to flexion. The anteroposterior meniscal movement was the greatest for the anterior horn of the medial meniscus and least for the posterior horn of the medial meniscus. In the mediolateral direction, meniscal extrusion was seen in 52% of the medial menisci in extensions (maximum 1.91 mm) and 29% of lateral menisci in flexions (maximum 2.36 mm). From the extension to flexion, all medial and lateral menisci moved significantly to the lateral side. Meniscal floating was frequently observed in the posterior horn of medial menisci in extension. Meniscal flounce was frequently seen in lateral menisci in flexion with a widened lateral tibiofemoral joint space gap. The coronal tibiofemoral angle showed medial wedging in flexion, but not in extension. CONCLUSIONS: Wide-bore 3-T closed MRI revealed significant kinematic changes in the menisci and tibiofemoral joint spaces in asymptomatic volunteers.

Lipoma arborescens associated with osseous/chondroid differentiation in subdeltoid bursa.

Lipoma arborescens (LA) is a rare benign lesion of unknown etiology. It is characterized histologically by villous proliferation of the synovial membrane and diffuse replacement of the subsynovial tissue by mature fat cells. This condition affects the knee joint most commonly. Cases involving other locations including glenohumeral joint,[1] hip,[2] elbow,[3] hand[4] and ankle[5] have been rarely described. Involvement of the subdeltoid bursa has also been reported, but to date no case has described LA with osseous/chondroid differentiation of this bursa. Another significant finding in our case was the coexistence of LA with intermuscular lipoma, SLAP lesion and labral cyst.

Total hip arthroplasty using S-ROM prosthesis for dysplastic hip.

PURPOSE: The purpose of this study was to evaluate the clinical and radiological results of total hip arthroplasty using a proximal modular femoral stem in patients who had secondary coxarthrosis associated with a dysplastic hip. MATERIALS AND METHODS: Forty-two patients (45 hips) with secondary coxarthrosis were evaluated after undergoing primary total hip arthroplasty using an S-ROM proximal modular femoral stem. The average follow-up was 80 months (range: 60 to 96 months). Clinical and radiological assessments were performed based on the Harris hip score and the radiological changes around the prosthesis. RESULTS: The average Harris hip score improved from 52.2 points to 88.5 points. All femoral stems showed stable fixation; there were 37 cases by bony ingrowth and 8 cases by stable fibrous ingrowth. Neither osteolysis nor progressive radiolucent lines around the femoral stem were found at the last follow-up. Forty-one hips (91.9%) revealed excellent or good clinical results at the most recent follow-up. CONCLUSION: For advanced secondary coxarthrosis, total hip arthroplasty with the use of the proximal modular femoral stem yielded good mid-term results with respect to the clinical and radiological criteria.

Clustered localized pigmented villonodular synovitis.

The localized form of pigmented villonodular synovitis (PVNS) is a rare pathologic entity characterized by limited involvement of the synovium. In the knee joint, which is the most commonly affected joint, the disorder generally presents as a single nodular lesion, or rarely as 2 or 3 multiple nodular lesions into the joint. We report 2 cases of localized PVNS in which multiple nodules were clustered in a limited patella fat pad area. Clustered, multiple nodular lesions in a limited area suggested to us to consider a variant of localized forms.

Lipoma arborescens of the knee.

Lipoma arborescens are rare lesions, typically located in the knee. They have a predilection for the suprapatellar pouch in the knee joint, but can also occur in any area of the knee joint. Magnetic resonance imaging of lipoma arborescens often reveals subchondral bone cyst and/or bone erosions, and there may appear to be a correlation between lipoma arborescens and osteoarthritis. We describe a case of histologically proven lipoma arborescens in the suprapatellar pouch and infrapatellar area of the knee with no damage to the posterior compartment and bone erosion in the proximal tibia without osteoarthritis.

M. chelonae soft tissue infection spreading to osteomyelitis.

A previously healthy, 54-year-old woman presented with Mycobacterium chelonae soft tissue infection and osteomyelitis of her left lower leg. The infection had started from soft tissue emerging at the medial aspect of the distal femur and had spread through the bone because of delayed diagnosis. The largely indolent, 8-month course to diagnosis was attributable to unremarkable clinical manifestations combined with a low index of suspicion such as immunocompetent patient and/or inadequate finding of acid-fast bacilli in a lesion smear, characteristic histopathological features, and culture techniques. Soft tissue infection and osteomyelitis were successfully treated without surgical intervention and with a 6-month course of chemotherapy.

Ganglion cysts of the posterior cruciate ligament.

Ganglion cysts arising from the posterior cruciate ligament (PCL) of the knee are rare. Thirteen cases have been reported with detailed description in the English literature. In this study, 3 cases of ganglion cyst arising from the PCL of the knee are described and comparatively reviewed with the literature. This case report draws attention to clinical symptoms and signs. We presume that rather than mechanical block, it is changes in the shape and dimension of the ganglion cyst with knee motion and posture that stimulate nerve endings in the synovial membrane, causing the development of knee pain and the limitation of knee motion.

Localized pigmented villonodular synovitis attached to the posterior cruciate ligament of the knee.

Localized pigmented villonodular synovitis (PVNS) of the knee joint is a rare pathological entity characterized by a limited involvement of the synovium. We report on a case of localized PVNS which was attached to the posterior cruciate ligament and presented pain without mechanical symptoms. The lesion did not reach dimensions sufficient to interfere with joint function. After arthroscopic removal of the tumor, the patient has maintained asymptomatic status during the 2 year follow-up period.

Tuberculous subdeltoid bursitis with rice bodies.

A 41-year-old woman with a 2-month history of diffused swelling and persistent dull pain in her right shoulder was examined. Magnetic resonance imaging (MRI) findings revealed subdeltoid bursitis and rice bodies with normal surrounding tissue and shoulder joint. Arthoscopic debridement and biopsy of the subdeltoid bursa were performed. Histologic examination of the bursal tissue showed granulomatous tissue with typical caseous necrosis. A positive culture of Mycobacterium tuberculosis confirmed the diagnosis of tuberculosis. We report on the clinical, radiological and athological findings in a patient with tuberculous subdeltoid bursitis accompanied by multiple rice body formation without coexisting active bone and joint tuberculosis, and conduct a literature review.