Conservative total hip arthroplasty: a procedure to conserve bone stock. Part I: analysis of sixty-six patients. Part II: analysis of failures.

Pain relief, function, and range of motion in surface replacement hip arthroplasty is comparable to the Charnley-type conventional arthroplasty. Patients with primary and secondary degenerative hip disease are the most suitable candidates for surface replacement. Previous operations, especially mold arthroplasty, increases incidence of failure. Osteopenia, obesity, or congenital deficiency of the acetabulum also increases the incidence of failure. Intraoperative preservation of abductor continuity and rigorous postoperative abductor strengthening are necessary to insure the success of the procedure. A minimum of 18 months is necessary to adequately evaluate the procedure. Acetabular loosening is avoidable. Hemispherical reaming of the femoral head did not contribute to femoral component loosening. Traumatic femoral neck fracture is a concern, but atraumatic femoral neck fracture can be avoided through improved operative technique, and by a program of rehabilitation of hip musculature. The procedure is indicated in the relatively young, well-motivated, non-obese patient with degenerative joint disease who has normal hip musculature.