Background:

Hip resurfacing arthroplasty (HRA) is a femoral bone-preserving alternative to total hip arthroplasty (THA) for younger, active patients. However, complications such as fractures, loosening, and metal wear can require conversion to THA. In some cases, revision of both the acetabular and femoral components is required.

Methods:

We conducted a retrospective review of 15 patients who underwent conversion of HRA to THA at a single, academic tertiary care centre between January 2011 and April 2024. Demographic data, surgical details, implant characteristics, and indications for conversion were collected. Postoperative outcomes including complications, reoperations, and revisions were investigated. Revision-free survival was estimated using Kaplan-Meier analysis.

Results:

The mean age was 53.2 years and mean time to conversion was 6.7 years. Indications for conversion included adverse reaction to metal debris (ARMD; n = 6), mechanical loosening (n = 3), component positioning and impingement (n = 3), periprosthetic fracture (n = 1), osteolysis/wear (n = 1), and prosthetic joint infection (PJI; n = 1). Common reasons for acetabular cup revision included ARMD (n = 6), loosening (n = 4), and positioning (n = 3). Dual-mobility (DM) constructs were used in 11 cases (73.3%). There were no dislocations. There was 1 90-day readmission due to persistent wound drainage which underwent debridement, antibiotics, and implant retention (DAIR) 14 days post-conversion. The average follow-up duration after the conversion procedure was 6.1 years. Kaplan-Meier analysis demonstrated 93% revision-free survival at one-year, which remained stable through 13 years.

Conclusions:

In this study of 15 both-component HRA conversions, we observed 93% revision-free survivorship at mid-term follow-up. While the small cohort size limits definitive conclusions, our findings suggest that revision of the acetabulum during conversion, particularly with dual-mobility constructs, may be an effective strategy to mitigate instability and manage metal-on-metal failure in appropriate patients. Further research with larger cohorts is warranted to confirm our findings.