Patient-Reported Outcomes After Distal Femur Fracture Fixation: A Retrospective Cohort Study of 151 Patients

OBJECTIVES: To evaluate 6-, 9-, and 12-month Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF), Global Health Physical (GH-Physical), and Global Health Mental (GH-Mental) scores after operative treatment of distal femur fractures. METHODS: Design: Retrospective cohort study. Setting: Two Level 1 Trauma Centers. Patients: Adult patients treated operatively for a distal femur fracture (AO/OTA 33A or 33C) between 2016 and 2024, with >= 1 PROMIS score available between 3 and 12 months postoperatively were identified. Patients undergoing reoperation for nonunion were excluded. Outcome Measures and Comparisons: PROMIS scores were determined as estimated marginal means to account for repeated observations. Mixed-effects linear regression was performed to identify factors (e.g., patient, injury, and treatment characteristics, and PROMIS-GH-Mental scores) associated with PROMIS-PF. RESULTS: Overall, 151 patients (median age 69 years [range: 21-84 years]; 66% female) were included. PROMIS-PF scores were 34.8 at 6 months, 36.3 at 9 months, and 37.9 at 12 months (P < 0.001). PROMIS-GH-Physical scores were 40.5, 40.9, and 41.3 (P = 0.35), and PROMIS-GH-Mental scores were 46.0, 46.6, and 47.2 (P = 0.25). In multivariable analysis, female sex (ss: -2.7, P = 0.010) and assisted baseline ambulation (ss: -4.1, P < 0.001) were associated with worse PROMIS-PF scores, whereas better PROMIS-GH-Mental scores at follow-up (1-unit increase ss: 0.36, P < 0.001) and follow-up duration (1-month increase: ss: 0.35, P = 0.006) were associated with better scores. CONCLUSIONS: PROMIS-PF scores improved over time but remained considerably lower than the US reference population at 12 months (ie, 38 vs. 50 points). Clinicians should educate patients that, although their fracture is healing as expected, their physical function will likely remain impaired at 12 months. The current study findings suggest that physical function during recovery from distal femur fractures is more affected by baseline functioning and mental health during follow-up than injury characteristics.