Clinical and Radiological Outcome of Acetabular Reconstruction Rings in Complex Primary and Revision Total Hip Arthroplasty.

Background: Acetabular reconstruction in complex primary and revision total hip arthroplasty (THA) with bone loss poses a great challenge. We aim to evaluate the medium-term clinical and radiological outcome of reconstruction rings used in these difficult situations.

Methods: We retrospectively reviewed a consecutive series of acetabular reconstructions with Muller ring or Bursh-Schneider cage from January 2009 to December 2016. The reconstruction rings were used in 66 hips (65 patients). There were 41 complex primary THA and 25 revision THA. The mean follow-up period was 76 months (range, 37-167 months). Clinical evaluation includes the assessment of Harris hip score, visual analogue scale (VAS) score, limb length discrepancy, and activities of daily living. The radiographs were analyzed for any signs of loosening, osteolysis, acetabular migration, and heterotopic ossification.

Results: The overall survival rate was 95% for revision in aseptic loosening and 87% for any reason at an average follow-up of 6.3 years. Twelve patients died and 9 patients were lost to follow-up leaving 45 patients for final functional analysis. Among the 45 patients, excellent to good results were seen in 33 patients, fair results were seen in 5 patients, poor results were seen in seven patients. Two patients had aseptic loosening and another two patients developed deep chronic infection awaiting two-stage revision.

Conclusion: Reconstruction rings still place a role in the armamentarium for complex acetabular reconstruction. It helps to reliably restore the bone stock, have an acceptable survival rate and satisfactory functional outcome at medium to long-term follow-up.