TWENTY-SIX YEARS OF EXPERIENCE WITH HEMI-RESURFACING ARTHROPLASTY FOR OSTEONECROSIS OF THE HIP

Abstract

Introduction: Management of osteonecrosis of the hip for Ficat stage III and IV disease remains controversial with the average age of the patients in the mid ‘30’s, and inferior long-term results of THA for this group. Consequently, some surgeons have favored bone-preserving procedures, and hemiresurfacing arthroplasty has been our preferred method of treatment.

Materials and Methods: Fifty-five hips (47 patients) with Ficat Stage II, III, or early IV osteonecrosis treated with hemiresurfacing by a single surgeon (HCA) were reviewed. The average age of the patients was 34 years (range, 18–52) and 74% of the patients were men. Three different resurfacing materials were used over the years: Titanium (11 hips), Alumina (12 hips), and cobalt-chromium (32 hips).

Results: The average follow-up was 13 years (range 2.6–26.5). There were no dislocations, femoral neck fractures, or osteolysis. The average UCLA hip scores for pain, walking, function, and activity improved from 4.8, 5.8, 5.2, and 4.2 to 7.9, 8.7, 7.7, and 5.6, respectively, at last follow-up. The Kaplan-Meier survival estimate was 81.8%, 58.3%, and 44.2% at 5, 10, and 15 years, using any revision as end point. Seventeen hips were converted: 15 for acetabular cartilage wear, one for enigmatic pain at 12 months, and one for sepsis at 3 months. We found no difference in survivorship between component materials (log-rank test; p=0.447).

Discussion: This experience indicates a greater that 80% survivorship at 5 years for this conservative procedure. Four patients have passed the 20-year landmark (one of them was revised at 23 years). The pain and function scores are lower than with THA or modern full resurfacing devices. A shorter duration of symptoms before surgery is favorable to survivorship of the procedure because we believe that articular cartilage is healthier. When necessary, conversion to total hip replacement is similar to a primary THA.