The Effect of Knee Flexion Contracture on Patient Reported Outcome Measures after Distal Femur Fractures (OTA/AO Type 33):A Multi-Center Prospective Evaluation

OBJECTIVES: · To determine if patients with knee flexion contracture after distal femur fracture have poorer outcomes than patients who regain full knee extension. · To determine if factors such as patient age, gender, open fracture or implant used favors knee flexion contracture. METHODS: Design: Prospective, multicenter trial Setting: Twenty academic level I trauma centers Patient Selection Criteria: Patients with a distal femur fracture. Patients were evaluated for knee flexion contracture at 3, 6 and 12 months post-operatively. Outcome Measures and Comparisons: SMFA, Bother Index and EQ Health Index scores were recorded. Walking and stair climbing ability were assessed. RESULTS: · 126 patients had radiographic follow up for 12 months. There was clinical follow-up for 99 patients at 3 months, 90 patients at 6 months and 74 pts at 12 months. · Patients with full knee extension had better SMFA scores at 12 months than patients with knee flexion contracture (p = 0.308). · Bother Index (p = 0.29) and EQ _{Health State} (p = 0.12) scores did not demonstrate a difference between patients with or without knee flexion contracture at any time point. · Patients with full knee extension had improved walking ability compared to patients with flexion contracture (p = 0.008). Patients with full knee extension had better stair climbing ability than patients with flexion contracture (p = 0.02). · Only older patient age showed a difference in likelihood of flexion contracture (p = 0.01) The rates of flexion contracture in women versus men (p = 0.51), RIMN versus LLP (p = 0.74) and open versus closed fracture (p = 0.24) were not statistically different. CONCLUSIONS: · Patients with knee flexion contractures after distal femur fracture do worse than patients who regain full extension. · Older patients with distal femur fractures are at greater risk for knee flexion contracture. LEVEL OF EVIDENCE: Level I