Distal Femoral Replacement for Periprosthetic Fractures After TKA: Australian Orthopaedic Association National Joint Replacement Registry Review

Background: Distal femoral replacement (DFR) is a potential treatment option following periprosthetic fracture (PPF) of a total knee arthroplasty (TKA). However, there is limited literature regarding implant survivorship and complication rates. The aim of this study was to examine patient demographics and trends in usage, implant survivorship and modes of failure, and patient mortality following DFR for PPF captured by a national joint replacement registry. Methods: A retrospective registry review was performed using data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). In total, 306 DFR were performed for PPF of a known primary TKA. Eighty-five percent of patients were female, and the mean age was 76.4 years. Kaplan-Meier estimates of implant and patient survivorship were performed. Results: The number of DFR performed for PPF has doubled over the past five years. The cumulative percent second revision rate at six years was 12%. The most common indications for revision were infection (37%) and aseptic loosening (33%). Patient survivorship after DFR was 97% and 83% at five and ten years, respectively. Conclusion: A national registry review has identified the increasing prevalence of DFR for PPF after primary TKA and demonstrated implant survivorship of 88% at midterm follow-up. Surgeons may consider DFR as an acceptable and durable treatment option. Level of Evidence: Level III - Case Series.