Early functional mobility predicts return to baseline function and discharge disposition after distal femur fractures in elderly.

Objective: Identify predictors of return to baseline function and ambulatory status in elderly patients after operative fixation of a distal femur fracture. Methods: Design: Retrospective cohort. Setting: Academic Level I Trauma Center. Patients/Participants: All ambulatory patients older than 55 years who underwent operative fixation of a distal femur fracture from 2013 to 2022. Intervention: Operative fixation of a distal femur fracture. Main Outcome Measurements: Activity Measure for Post-Acute Care (AM-PAC) score, weight bearing restriction, discharge disposition, and ambulatory status. Results: One hundred ninety-nine patients were included with average follow-up of 1.2 years. AM-PAC scores were not associated with preoperative ambulatory status, weight bearing restrictions, fracture classification, or time to weight bearing. However, lower AM-PAC was associated with longer time to surgery, open fractures, single implant constructs, longer length of stay, and discharge to facility. At 90 days postoperatively, patients with lower AM-PAC were also more likely to be dependent on ambulatory aids and less likely to return to baseline mobility. When controlling for demographics and fracture characteristics, AM-PAC of 11+ was independently predictive of reaching preinjury ambulatory status by 90 days (odds ratio [OR] 5.23, Conclusions: Weight bearing restrictions after elderly distal femur fractures do not affect early postoperative mobility. However, the importance of early mobility and preoperative ambulatory status cannot be underestimated as they are independently predictive of ambulatory independence and return to preinjury function by 90 days. AM-PAC may help identify patients needing additional interventions to improve function, discharge disposition, and risks associated with prolonged immobility. Level of Evidence: III.