Advances in hip arthroplasty in the treatment of osteonecrosis.

Osteonecrosis of the femoral head is a devastating disease for which many patients will eventually require total hip arthroplasty. Standard total hip arthroplasties have historically had poor results in patients with osteonecrosis. More recently, reports have shown excellent results with second- and third-generation designs that incorporate advances in bearing technology. However, there are still certain subpopulations of patients (those with sickle cell disease, those with systemic lupus erythematosus, and those who have undergone renal transplantation) that have less than optimal results. Other hip arthroplasty alternatives include bipolar hemiarthroplasty, limited femoral resurfacing, and metal-on-metal resurfacing. Bipolar hemiarthroplasty historically and currently has consistently poor results in most studies and should be avoided in patients with osteonecrosis. In multiple reports, limited femoral arthroplasty has demonstrated reasonable midterm and long-term outcomes as a temporizing procedure, with results being less predictable than for standard total hip arthroplasty. Recently, ceramic-on-ceramic and metal-on-metal resurfacing hip arthroplasty has emerged as a viable option that has been used to treat patients with osteonecrosis of the femoral head, and several studies have shown promising short-term outcomes. Overall, however, recent studies have shown more optimal outcomes with hip arthroplasty than resurfacing hip arthroplasty, which makes standard hip replacements, as well as other arthroplasty alternatives, more attractive for young patients with this disease.