AL/AL bearing couples decreased the cumulative risk of dislocation as compared with AL/PE bearing couples.

Background Although not all elderly patients with femoral neck fractures are candidates for THA, active, mentally competent, independent patients achieve the most durable functional scores with THA compared with hemiarthroplasty. However, a relatively high frequency of early or late dislocation could reduce the potential benefits with THA.

Background Patients with THA requiring cup revision for acetabular osteolysis may have a stable stem component without loosening. However, it is unclear whether isolated cup revision halts femoral osteolysis progression. Question/purposes We asked (1) whether and to what degree osteolysis progresses after isolated acetabular revision with a change of the femoral head and (2) whether an alumina or metal bearing better reduces osteolysis progression and wear with a polyethylene (PE) cup. Methods We retrospectively evaluated 150 patients who underwent 165 acetabular revisions but no treatment for proximal femoral osteolysis in hips with stable femoral components. Mean age at revision was 63 years (range, 48-74 years). All hips received a new PE cup; 83 hips received new alumina heads and 82 new metal heads. Radiographs (mean followup, 15 years; range, 10-25 years) were assessed to measure osteolysis, loosening, and PE wear. Revisions of the femoral stem were recorded.

Case reportA 16 year old girl developed insidious left groin pain after an 18 month period of limping before being seen in the department of rheumatology. No other complaint or remarkable history was noted. Pain was relieved by bed rest but was worse at night in particular after sport practice at school. Non-steroidal anti-inflammatory drugs (diclofenac, 75 to 100 mg/day) and analgesics (paracetamol, 2 to 3 g/day) were both effective. Physical examination revealed only decreased internal rotation of the left hip joint (5°) and atrophy of the left thigh (a 2 cm decrease in the circumference). Initial pelvic x rays performed nine months after onset were normal. Technetium-99m bone scan performed six months after initial x rays showed diVuse increased uptake over the hip including the femoral head, femoral neck, and acetabulum ( fig 1A). Magnetic resonance imaging (MRI) showed decreased bone marrow signal intensity on T1 weighted images and increased signal intensity on T2 weighted images in the femoral neck with joint eVusion. These changes were interpreted as depicting a possible stress fracture. However, computed tomography with 4 mm contiguous sections