Functional outcome and persistent disability after isolated fracture of the femur.

Background: The purpose of this study was to assess the functional outcome and causes of persistent disability in patients with isolated femoral shaft fractures treated at an academic level-1 trauma centre.

Methods: We prospectively enrolled 40 consecutive skeletally mature patients with isolated, nonpathologic diaphyseal femur fractures. All patients underwent fracture reduction and fixation using an antegrade locked intramedullary nail. We measured functional outcome using the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index and the Short Musculoskeletal Functional Assessment (SMFA). We obtained visual analog scores for pain in the groin, buttock, thigh and knee 6 months after the injury.

Results: Joint-related and musculoskeletal outcome scores improved gradually from the baseline assessment to the 6-month review. Mean scores (and standard deviations [SDs]) on the WOMAC index improved gradually from 57 (23) to 24 (22) for pain, from 57 (25) to 30 (20) for stiffness and from 70 (21) to 21 (23) for function (p < 0.001). The mean SMFA score (and SD) improved from 64 (13) to 25 (20) (p = 0.024). We noted no further improvements in functional outcome measures from the 6-month to the 12-month assessment (p > 0.21). Patients reported more pain in the knee than in other anatomic locations; the mean pain scores (and SDs) were 3.7 (3.1) in the knee, 2.5 (2.7) in the thigh, 1.7 (2.7) in the buttock and 1.0 (1.7) in the groin (p = 0.003). We noted correlations between knee pain and WOMAC pain (rho = 0.748, p < 0.001), function (rho = 0.701, p < 0.001) and SMFA (rho = 0.733, p < 0.001). We noted weaker correlations between thigh, groin and buttock pain and functional outcomes, with rho scores ranging from 0.2 to 0.55.

Conclusion: Recovery from femur fractures occurs most rapidly in the first 6 months after injury. Residual deficits in functional outcome were still measurable 12 months after injury. Knee pain was the most common and most severe source of patient discomfort 12 months after isolated femur fractures, and demonstrated moderate to good correlation with general and joint-specific functional outcome measures.