Supplemental fixation of distal femur fractures: a review of biomechanical and clinical evidence

Background: Fixation of distal femur fractures with lateral locking plates has relatively high rates of clinical failure. Supplemental fixation has shown promising results, and may reduce rates of fixation failure or nonunion. This review aimed to assess the biomechanical and clinical evidence regarding the use of supplemental fixation of distal femur fractures. Methods: PubMed, Embase, and Cochrane databases were searched for English language studies up to December 4, 2020, identifying 1,829 studies. Biomechanical studies that assessed fracture displacement, load/cycles to failure, or construct stiffness and clinical studies that assessed fixation failure or nonunion after supplemental fixation of distal femur fractures were included. Studies with sample size ≤5, ORIF with non-locking plates, periprosthetic distal femoral fractures, nonunions or revision surgeries were excluded. Results: Seventeen studies were included, of which 8 were biomechanical and 9 clinical. Overall, biomechanical studies demonstrated increased construct stability and load to failure with various supplemental fixation strategies. Clinical studies demonstrated more mixed outcomes for nonunion and fixation failure rate among the various techniques. Conclusions: Biomechanical studies have demonstrated potential benefits of these strategies, but there remains a dearth of high-quality evidence evaluating their effect on clinical outcomes. Prospective RCTs are necessary to address these issues and confirm the results in the existing literature. Level of Evidence: IID