Abstract
Introduction: Osteolysis is a significant problem associated with hip replacement. In the early stages of osteolysis, when the implant is still stable, formal revision is technically demanding and may result in signififant bone loss. A recently described technique for acetabular component revision addresses osteolysis, retaining the acetabular cup and cementing a new polyethylene liner.
Materials and Methods: Between January 2000 and December 2003, 29 liner cementation revisions in 27 patients were performed. The mean age was 61 years (range 37–77), the mean time elapsed after the original surgery was 6.7 years (3–14). 23 of the hips (79%) were ABG (Howmedica). Only 20 (69%) of the patients were clinically symptomatic. At surgery the polyethylene was removed and osteolytic cysts were debrided. Then, the metal acetabular component was tested for stability. Obviously, only stable metal implants were not revised. The cysts were filled with bone graft or bone substitute and a new polyethylene liner was cemented in with methylmetacrilate augmented gentamicin. The patients were evaluated by modified Harris Hip Score (HHS) and by SF-12 score. The mean follow up was 25 months (10–45).
Results: The average HHS was 86/4 and its pain component was 38.8. The average physical component of SF-12 was 45.9 (19.5–57.2) and the average metal component was 54.6 (29–66.9). The post-operative HHS and the SF-12 scores were high (good or excellent) in all patients reflecting good clinical outcome. In patients who were asymptomatic prior to surgery, both the HHS and the pain score were significantly higher compared to the symptomatic patients (p< 0.01). One patient with extensive bone loss needed revision surgery due to early postoperative fracture of the acetabulum, and another patient had recurrent dislocations that required revision.
Summary: We conclude that revision of the polyethylene liner and cementation of a new one is a safe and useful technique in patients with stable acetabular shell. This is especially true for asymptomatic patients with osteolysis.
The abstracts were prepared by Ms Orah Naor. Correspondence should be addressed to Israel Orthopaedic Association at PO Box 7845, Haifa 31074, Israel.
