The pattern of bone mineral density in the proximal femur and radiographicsigns of early joint degeneration

Objective. To determine if the presence of early radiographic signs of dege nerative changes in the hip is associated with the pattern of bane mineral density (BMD) in the proximal femur. Methods. Twenty-eight patients scheduled for unilateral hip replacement wer e placed into one of 2 groups based on the preoperative radiographic findin gs in the asymptomatic hip: Group I (no changes) or Group 2 (doubtful or mi nimal changes). Both femora and the lumbar spine were scanned by dual energ y x-ray absorptiometry. Results. The BMD z scores of the asymptomatic hip were significantly higher at the neck and Ward's triangle sites in Group 2 compared to Group I (p < 0.05), There were no differences between the groups in the symptomatic hip except at Ward's triangle, where Group 2 had higher z scores than Group 1 ( p < 0.05). The lumbar BMD z scores were elevated in both groups (p < 0.05). Conclusion. Proximal femur BMD in the asymptomatic hip of patients schedule d for unilateral hip replacement is elevated when there are early radiograp hic signs of hip osteoarthritis (OA), consistent with the idea that early O A involves bone as well as cartilage.