Acetabular Augments Used in Revision Hip Arthroplasty: Minimum 10-year Follow-Up of Implant Survivorships, Functional Scores, and Radiographic Outcomes

Background: Acetabular bone loss is a major challenge in the setting of revision total hip arthroplasty (THA). Porous tantalum augments have emerged as a viable solution to acetabular bone loss in revision THA. The purpose of this study was to evaluate the survivorship, clinical, and radiological outcomes of these implants.

Methods: We identified 104 augment implants from our retrospective chart review of revision THA from June 2003 to July 2013. Of these patients, 75 (72.1%) were women, the mean age at surgery was 66 years (range, 27 to 87), and the mean follow-up was 13.2 years (range, 0.25 to 18.2). Kaplan-Meier survival analysis was performed, with failure defined as revision for aseptic loosening of the acetabular reconstruction.

Results: There was significant improvement in the Harris Hip Score from 40.0 to 77.3 (P < 0.001) and the Oxford Hip Score from 14.9 to 36.3 (P < 0.001). Survivorship for failure due to aseptic loosening was 98.8% (95% CI [confidence interval] 96.4 to 100) at 24 months with 60 hips at risk, and 90.4% (95% CI 83.0 to 97.8) at 60 and 120 months with 38 and 18 hips at risk, respectively. The overall number of complications was 34 (32.7%). Of these complications, 21 (20.2%) required repeat revision surgery. The revision rate due to aseptic loosening of the augment, infection, dislocation, aseptic loosening of the femoral component, reconstruction failure, and heterotopic ossification was seven (6.7%), five (4.8%), four (3.8%), two (1.9%), two (1.9%), and one (0.96%), respectively.

Conclusions: Treatment of acetabular defects during revision THA using porous tantalum augments provides acceptable implant survivorship and favorable clinical outcomes at mid-term (5 to 10 years) and long-term (> 10 years) follow-up.