Functional Outcome After Successful Internal Fixation Versus Salvage Arthroplasty of Patients With a Femoral Neck Fracture

OBJECTIVES: To determine patient independency, health-related and disease-specific quality of life (QOL), gait pattern, and muscle strength in patients after salvage arthroplasty for failed internal fixation of a femoral neck fracture. DESIGN: Secondary cohort study to a randomized controlled trial. SETTING: Multicenter trial in the Netherlands, including 14 academic and nonacademic hospitals. PATIENTS: Patients after salvage arthroplasty for failed internal fixation of a femoral neck fracture were studied. A comparison was made with patients who healed uneventfully after internal fixation. INTERVENTION: None (observatory study). MAIN OUTCOME MEASUREMENTS: Patient characteristics, SF-12, and Western Ontario McMaster osteoarthritis index scores were collected. Gait parameters were measured using plantar pressure measurement. Maximum isometric forces of the hip muscles were measured using a handheld dynamometer. Differences between the fractured and contralateral leg were calculated. Groups were compared using univariate analysis. RESULTS: Of 248 internal fixation patients (median age, 72 years), salvage arthroplasty was performed in 68 patients (27%). Salvage arthroplasty patients had a significantly lower Western Ontario McMaster osteoarthritis index score (median, 73 vs. 90; P = 0.016) than patients who healed uneventfully after internal fixation. Health-related QOL (SF-12) and patient independency did not differ significantly between the groups. Gait analysis showed a significantly impaired progression of the center of pressure in the salvage surgery patients (median ratio, -8.9 vs. 0.4, P = 0.013) and a significant greater loss of abduction strength (median, -25.4 vs. -20.4 N, P = 0.025). CONCLUSIONS: Despite a similar level of dependency and QOL, salvage arthroplasty patients have inferior functional outcome than patients who heal after internal fixation of a femoral neck fracture. LEVEL OF EVIDENCE: Therapeutic level III.