Functional Outcomes After Operatively Treated Patella Fractures

OBJECTIVES:To evaluate the midterm functional outcomes of patients with isolated operatively treated patella fractures. DESIGN:Prospective cohort and retrospective clinical and radiographic assessment. SETTING:A Level I and Level II trauma center. PATIENTS/PARTICIPANTS:Two hundred forty-one patients underwent operative intervention for a displaced patella fracture between 1991 and 2007. After appropriate exclusions, 110 patients met criteria. A total of 40 (36%) patients with isolated, unilateral, operatively treated patella fractures with minimum 1-year follow-up agreed to participate in this study and return for functional testing. Mean follow-up was 6.5 years (range, 1.25–17 years). INTERVENTION:Enrolled patients were treated with one of the following methodsstandard tension band with Kirschner wires, tension band through 2 cannulated screws, longitudinal anterior banding with cerclage, or partial patellectomy. MAIN OUTCOME MEASUREMENTS:All enrolled patients were evaluated with the SF-36 and an injury-specific questionnaire (Knee Injury and Osteoarthritis Outcome Scores) and asked to self-report symptomatic hardware. Patients were also evaluated by physical examination assessing range of motion and Biodex bilateral quadriceps isometric and isokinetic comparisons. RESULTS:The mean normalized SF-36 physical composite score and the mean normalized Knee Injury and Osteoarthritis Outcome Scores subscale scores (pain, 71.7; symptoms, 66.3; activities of daily living, 75.1; sport/recreation, 45.2; quality of life, 49.6) were statistically different (P < 0.05) from reference population norms. Removal of symptomatic fixation was required in 52% of the patients treated with osteosynthesis, whereas 38% of those with retained fixation self-reported implant-related pain at least some of the time. Eight patients (20%) had an extensor lag greater than 5°. A restricted range of flexion of greater than 5° was noted in 15 patients (38%) and restricted range of extension of greater than 5° was noted in 6 patients (15%). Biodex dynamometric testing revealed a mean isometric extension deficit of 26% between the uninvolved and involved sides for peak torque. Extension power was also tested with an angular velocity of 90°/sec and 180°/sec and mean deficits of 31% and 29% were noted, respectively, when compared with the contralateral extremity. CONCLUSIONS:At a mean of 6.5 years after operative treatment for patella fractures, significant symptomatic complaints and functional