REVISION TOTAL HIP ARTHROPLASTY IN PATIENTS WITH OSTEONECROSIS
Hungerford M; Jones LC; Khanuja HP; Pietryak P Hungerford D

Previous studies have indicated that the rate of successful long-term outcomes of primary total hip arthroplasty (THA) is lower for patients with osteonecrosis as compared to patients with osteoarthritis. Less is known about the long-term outcomes of revision THA in the same patient population. The purpose of this study was to characterize the clinical outcomes of revision THA patients that have been diagnosed with osteonecrosis.

Seventy-two hips in sixty-three patients diagnosed with osteonecrosis were identified. The patient cohort included 30 males (35 hips) and 33 females (37 hips). The mean age was 47 years (range 28-83). Indications for revision of the index operation included: osteolysis (8), loosening (50), polyethylene wear (3), infection (3), fractures (2), malposition (2), acetabular erosion (1), subsidence (1), subluxation (1) and dislocation (1). A Kaplan-Meier survival analysis was performed.

There was a mean follow-up of 66 months. Sixteen hips were re-revised (22.2%) with the time since the index operation ranging from one to 130 months (mean 61 months). Reasons for revision included: loosening (10), osteolysis (1), subluxation (1), infection (1), dislocation (1), stem fracture (1), cyst/loosening (1).

A successful outcome was observed for 77.8% of the osteonecrosis patients. The reasons for re-revision are similar to those for rev-THA patients without osteonecrosis. It remains to be determined if the high rate of loosening is a consequence of the disease, activity level of this relatively young patient population or the response to wear particles from the articulating surfaces of the prosthetic components.