Custom Triflange Acetabular Implants: Average 10-Year Follow-Up.

Background: Acetabular reconstruction options in the setting of substantial bone deficiency (Paprosky 3A and 3B) remain limited. Custom triflange acetabular implants are one choice for this challenging problem. However, few studies have reported on survivorship beyond 3 to 5 years. The purpose of this study was to report our 6 to 13-year clinical results using these custom-made acetabular components.

Methods: Between 2008 and March 2015, 42 revision total hip arthroplasties (41 patients) were performed at our institution with a custom triflange acetabular component. All revisions involved either Paprosky 3A or 3B acetabular defects. Two patients died before the five-year follow-up. Harris Hip Scores were obtained at 6 months, 1 year, and every 2 to 3 years thereafter. The average follow-up in the remaining 40 revision total hip arthroplasties was 10 years (range, 6 to 13 years).

Results: At the final follow-up, the mean Harris score was 74 points. There were two deep infections (5%). One custom implant was removed for deep infection (2.5%). Three hips (7.5%) experienced a total of four dislocations necessitating revision in one hip (femoral component only). One custom implant was judged to be loose. There were no cases of femoral nerve palsy. At final follow-up, 38 (95%) of the custom acetabular implants were considered radiographically stable.

Conclusion: Instability and infection remain a major concern and cause of failure in these complex reconstructions. At an average follow-up of 10 years, however, custom triflange acetabular implants appear to work at least as well as jumbo cups and cup/cage constructs in the setting of extensive erosion of acetabular bone.