Bone mineral density in patients with rapidly destructive or common hip osteoarthritis.

BACKGROUND Recent findings that subchondral insufficiency fracture in the femoral head may precede rapid chondrolysis suggest a role for systemic low bone mass in the genesis of rapidly destructive hip osteoarthritis (RDHOA). OBJECTIVE To compare bone mineral density (BMD) in females with RDHOA and those with common hip osteoarth-ritis (OA). METHODS This prospective case-control study involved 26 females with RDHOA recruited from our institution between March 2000 and November 2006. BMD was measured at the femoral neck and lumbar spine (L1-L4) by dual-energy x-ray absorptiometry. For comparison, BMD was measured in 33 women with common hip OA who were scheduled for primary total hip arthroplasty. RESULTS Patients with RDHOA and those with common hip OA were similar in age (74.9+/-9.9 vs. 74.7+/-8.8 years) and BMI (26.3+/-4.3 vs. 26.3+/-5 g/m2) and did not differ in mean BMD at the lumbar spine (1.0+/-0.2 vs. 1.1+/-0.2 g/cm2; mean T-score: -0.6+/-1.3 vs. -0.8+/-1.5) or at the femoral neck (0.7+/-0.1 vs. 0.8+/-0.2 g/cm2; mean T-score: -1.5+/-1.1 vs. -1.4+/-1.4). CONCLUSION The results of this study do not suggest a role for systemic low bone mass in the pathophysiology of RDHOA.