Two-Year Results of Ceramic-on-Ceramic Hip Resurfacing in an International Multicenter Cohort

Introduction Hip resurfacing arthroplasty (HRA) is a bone-conserving alternative to total hip arthroplasty. We present the two-year clinical and radiographic follow-up of a novel ceramic-on-ceramic (CoC) HRA in an international multicenter cohort. Methods Patients undergoing HRA between September 2018 and January 2021 were prospectively included. Patient-reported outcome measures (PROMS) in the form of the Forgotten Joint Score (FJS), Hip Disability and Osteoarthritis Outcome Score (HOOS) Jr., Western Ontario and McMaster Universities Arthritis Index (WOMAC), Oxford Hip Score (OHS), and University of California, Los Angeles (UCLA) Activity Score were collected preoperatively, and at 1- and 2-years post-operation. Serial radiographs were assessed for migration, component alignment, evidence of osteolysis or loosening, and heterotopic ossification formation. Results The study identified 200 patients who reached a minimum 2-year follow-up (mean 3.5 years). Of these, 185 completed PROMS follow-up at 2 years. There was a significant improvement in HOOS (P < 0.001) and OHS (P < 0.001) between the pre-operative, 1-year, and 2-year outcomes. Patients also reported improved pain (P < 0.001), function (P < 0.001), and reduced stiffness (P < 0.001) as measured by the WOMAC score. Patients had improved activity scores on the UCLA Active Score (P < 0.001), with 45% reporting a return to impact activity at 2 years. At 1 and 2 years, the FJS was not significantly different (P = 0.38). There was no migration, osteolysis, or loosening of any of the implants. The mean acetabular cup inclination angle was 41.3 degrees, and the femoral component shaft angle was 137 degrees. No fractures were reported over the 2-year follow-up, with only 1 patient reporting a sciatic nerve palsy. There were 2 revisions, one for unexplained pain at 3 months due to acetabular component malposition and one at 33.5 months for acetabular implant failure. Conclusion The CoC resurfacing at 2 years post-operation demonstrates promising results with satisfactory outcomes in all recorded PROMS. Further long-term data is needed to support the widespread adoption of this prosthesis as an alternative to other HRA bearings.