Outcomes of Periprosthetic Distal Femur Fractures by Fixation Construct: A Retrospective Cohort Study

Periprosthetic distal femur fractures (PDFFs) are increasing with rising arthroplasty volumes. An optimal fixation strategy remains debated. This study evaluated outcomes of single lateral locking plate constructs (sLLPs), retrograde intramedullary nails (IMNs), and dual constructs (nail-plate or dual plating).

A retrospective cohort study was done at a level I trauma center (2012 to 2024). Adults with PDFF (AO/Orthopaedic Trauma Association 33) treated with sLLP, IMN, or dual constructs were included. All patients were assessed for postoperative weight-bearing status, while clinical outcomes required ≥6-month follow-up or earlier documented complications. Outcomes included revision surgery, infection, implant failure, hardware removal, wound dehiscence, and time to weight bearing as tolerated (WBAT).

Of 99 identified patients, 64 met criteria (IMN: n = 20; sLLP: n = 19; dual: n = 25). Mean age was 69.0 years; 75.0% female, 59.4% Black; mean follow-up 391.5 days. Immediate WBAT was ore common in dual (70.7%) and IMN (52.8%) groups than sLLP (9.1%; P < 0.001). Mean time to WBAT was shortest with dual constructs (13.8 days), followed by IMN (26.0) and sLLP (42.8; P = 0.020). On multivariable analysis, sLLP fixation was associated with increased odds of unplanned revision surgery (OR 6.27, 95% confidence interval, 1.29 to 30.50, P = 0.023), while neither IMN (P = 0.157) nor dual constructs (P = 0.071) demonstrated a significant association.

Single lateral locking plate fixation in PDFF was associated with higher odds of unplanned revision surgery. Dual construct patients had the shortest time to postoperative weight bearing and were more frequently permitted WBAT immediately after surgery.