Objective: To determine if the presence of early radiographic signs of degenerative changes in the hip is associated with the pattern of bone mineral density (BMD) in the proximal femur.
Methods: Twenty-eight patients scheduled for unilateral hip replacement were placed into one of 2 groups based on the preoperative radiographic findings in the asymptomatic hip: Group 1 (no changes) or Group 2 (doubtful or minimal changes). Both femora and the lumbar spine were scanned by dual energy 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 1 (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 scheduled for unilateral hip replacement is elevated when there are early radiographic signs of hip osteoarthritis (OA), consistent with the idea that early OA involves bone as well as cartilage.