Far Cortical Locking Versus Standard Constructs for Locked Plate Fixation in the Treatment of Acute, Displaced Fractures of the Distal Femur

Abstract

Background: Fixation of distal femoral fractures remains a challenge, and nonunions are common with standard constructs. Far cortical locking (FCL) constructs have been purported to lead to improved fracture-healing as compared with that achieved with traditional locking bridge plates. We sought to test this hypothesis in a comparative effectiveness clinical trial. Methods: This randomized trial was performed across 16 centers and included adult patients with an AO/OTA type 33A or 33C distal femoral fracture that was suitable for bridging fixation. We excluded patients with periprosthetic fractures. Participants were randomly assigned to either FCL fixation or standard locking plate fixation. The primary outcome was a hierarchical composite of radiographic and clinical fracture-healing at 3 months after fixation. We estimated between-group differences with use of the win ratio approach. Secondary outcomes included radiographic healing, clinical fracture-healing, complications, reoperations, and health-related quality of life (Short Form-36 Health Survey Version 2 [SF-36] Physical Component Summary and Mental Component Summary scores) at 3, 6, and 12 months after fixation. Results: We randomly assigned 193 patients to treatment with either FCL screws (96 patients) or standard screws (97 patients). The study population had a mean age of 63.4 years, consisted predominantly of women (68%), and was well-balanced between AO/OTA 33A and 33C fractures. Based on 4,355 pairwise comparisons, the calculated win ratio was 1.18 (95% confidence interval [CI], 0.77 to 1.79; p = 0.45), indicating that patients assigned to FCL screws had better outcomes in 51% of the comparisons. Radiographic healing did not differ significantly between the groups (odds ratio, 1.36; 95% CI, 0.69 to 2.72; p = 0.38), nor did Function IndeX for Trauma (FIX-IT) scores (p = 0.41). There were no significant differences between the groups in terms of SF-36 Physical Component Summary scores at 3 months or in the change in scores at 12 months after fixation. Conclusions: In this multicenter randomized trial of adult patients with an AO/OTA type 33A or 33C distal femoral fracture, similar clinical and radiographic healing outcomes were observed in the FCL and standard fixation groups. Level of Evidence: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.