Good mid‐ to long‐term survivorship and low rates of aseptic loosening of a cementless primary press‐fit acetabular cup for contained defects in revision total hip arthroplasty
Kevin‐Arno Koch, Benjamin Zimmer, Raphael Trefzer, Mustafa Hariri, Tilman Walker, Christian Merle, Johannes Weishorn, David SpranzAbstract
Purpose
Acetabular revision total hip arthroplasty (rTHA) remains challenging, and evidence on the use of primary press‐fit cups in the revision setting for contained acetabular defects is limited. This study evaluated mid‐ to long‐term implant survivorship, reoperation rates and clinical and radiographic outcomes of a cementless primary press‐fit acetabular cup used for acetabular revision.
Methods
This retrospective single‐centre study included 107 hips in 106 patients undergoing acetabular rTHA using a cementless primary press‐fit cup. Implant survivorship was assessed using cumulative incidence functions for acetabular re‐revision for any reason, re‐revision for aseptic loosening and reoperation for any reason, with death treated as a competing event. Fine and Gray subdistribution hazard models were used to evaluate potential risk factors. Patient‐reported outcome measures included the Harris Hip Score (HHS) and the University of California Los Angeles (UCLA) activity score. Radiographic evaluation was performed using standardised classifications.
Results
Cumulative incidence of acetabular re‐revision for any reason was 5.9% at 5 years and 9.8% at 10 years. Re‐revision for aseptic loosening occurred in two hips (1.9%), corresponding to survivorship of 99.0% at 5 years and 95.0% at 10 years. The cumulative incidence of reoperation for any reason was 21.7% at 10 years. Previous revision surgery was the only factor associated with an increased risk of subsequent failure. Mean HHS increased from 47 to 76, and the median UCLA activity score from 4 to 6. No radiographic acetabular loosening was observed among patients available for radiographic follow‐up.
Conclusion
In selected acetabular revision cases with contained defects, cementless primary press‐fit acetabular cups demonstrated favourable mid‐ to long‐term implant survivorship. Postoperative functional outcomes were comparable to those reported in the existing revision THA literature. Aseptic loosening accounted for only a minority of failures, suggesting durable biological fixation in this revision setting.
Level of Evidence
Level III, retrospective cohort study.