Today's News

Thursday, February 13, 1997

Younger osteonecrosis patients need more hip replacement revisions

A minimum 10-year follow-up of matched pairs of 94 patients with osteonecrosis and 94 patients with osteoarthritis, all of whom had total hip arthroplasties, found that the revision rate was almost the same.

The most significant finding of the study to be presented Thursday in scientific paper 173, is that when the results are viewed by age groups, there was a high rate of hip replacement revisions and radiographic loosening among patients less than 50 years of age. Cedric J. Ortiguera, MD, department of orthopaedics, Mayo Clinic, Rochester, Minn., will present the paper.

Complication rates were the same for both diagnoses, however there were more dislocations in patients with osteonecrosis. The authors said that "the higher incidence we observed might be related to the fact that patients with osteonecrosis have much less soft tissue constraint (stiffness) than patients with osteoarthritis and therefore might potentially reach a higher range of motion which would, in turn, make them more susceptible to dislocation."

The authors concluded that "in counseling patients prior to total hip replacement, older patients with avascular necrosis should be warned about the possibility of dislocation. Cemented total hip arthroplasty should be recommended only with caution in patients with osteonecrosis younger than 50 years and other more conservative treatment alternatives should be entertained, if at all feasible, in an effort to gain some time prior to hip replacement."

Co-authors of the study, both of Mayo Clinic, are Ian Pulliam, DO, and Miguel E. Cabanela, MD.