JOA - 2026-04-20 - Journal Article
Outcomes of Conversion of Hip Resurfacing Arthroplasty to Total Hip Arthroplasty with Retention of the Acetabular Component.
Antonioli SS, Kennedy MF, Bussey-Sutton C, Marwin S, Schwarzkopf R, Macaulay W
Topics
Key Takeaway
Conversion of HRA to THA with acetabular component retention achieves 100% acetabular component survivorship and 81.2% all-cause revision-free survivorship at 10 years, but carries a 7.5% PJI rate consistent with revision rather than primary THA benchmarks.
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Summary
This study asked whether retaining a well-fixed HRA acetabular component during conversion to THA yields durable survivorship. Forty patients underwent HRA-to-THA conversion with acetabular retention (97.5% converted to dual-mobility constructs) at a mean 8.2 years post-index HRA. All-cause revision-free survivorship was 90.0% at 1 year and 81.2% at 10 years; acetabular component survivorship was 100%, but 6 patients (15%) required reoperation including 3 for PJI.
Key Limitation
The small cohort (n=40) with heterogeneous conversion indications and a mean follow-up of 4.1 years underpowers the 10-year Kaplan-Meier estimate and prevents subgroup analysis by conversion indication.
Original Abstract
BACKGROUND
Complications of hip resurfacing arthroplasty (HRA) may require conversion to total hip arthroplasty (THA). While well-fixed acetabular components are often retained during conversion, data on implant survival and associated risks are limited. This study evaluated implant-related outcomes, survivorships, and complications in patients who undergo HRA to THA conversion with acetabular component retention.
METHODS
A retrospective review of 40 patients having undergone conversion from HRA to THA was conducted. Patients were included if the original HRA acetabular component was retained, provided they had at least one year of clinical follow-up. Demographics, perioperative variables, implant characteristics, and clinical outcomes were collected via chart review. The mean time to conversion was 8.2 years (range, 0.1 to 14.2) with an average of 4.1-years of follow-up (range, 1.0 to 10.9). Common indications for conversion included metallosis (40.0%), mechanical loosening (32.5%), and periprosthetic fracture (22.5%). Most cases (97.5%) were converted to dual-mobility constructs.
RESULTS
There were six patients (15.0%) who underwent subsequent reoperation following conversion, including three for infection, one for dislocation, and two for aseptic stem loosening. Kaplan-Meier analysis demonstrated an all-cause revision-free survivorship of 90.0% at one year and 81.2% at 10 years, with aseptic survivorship of 88.5% and acetabular component survivorship of 100% through final follow-up.
CONCLUSION
Conversion of HRA to THA with retention of a well-fixed acetabular component and conversion to a dual-mobility construct provides durable survivorship up to 10 years (mean follow-up: 4.1 years). However, the rates of periprosthetic joint infection (PJI) and reoperation are more aligned with those seen in revision THA than primary THA, emphasizing the need for careful patient selection and transparent preoperative counseling. These findings highlight that while this approach can be an effective option for failed hip resurfacing, appropriate caution is warranted to mitigate the elevated risks of infection and reoperation in this cohort.