Mid-term Prospective Follow-up of Ankle Fracture Fixation Using Patient Reported Outcome Measures

Abstract

Category: Trauma Introduction/Purpose: Open reduction and internal fixation (ORIF) is a common procedure to stabilise unstable ankle fractures. Anatomical reduction and stable fixation is desirable to achieve good clinical and radiological outcome after this injury. This prospective study examines the correlation between mid-term patient reported outcome measures (PROMs) and quality of fracture reduction of adult patients with ankle fractures treated with ORIF. Methods: A total of 100 patients with unstable ankle fracture who underwent ORIF were prospectively entered into the study between Nov 2013 to Oct 2014. Exclusion criteria were: age <18 years, pathological or open fractures and patients with cognitive impairment. Two independent observers assessed fracture patterns and quality of reduction. Fixations were analysed using Pettrone’s criteria including assessment of fracture displacement, medial clear space and tibiofibular overlap. Patients were followed up at two years post-operatively with postal questionnaires. Validated PROMs, Olerud-Molander Score (OMAS) and the Lower Extremity Functional Scale (LEFS) were used. For both scores a higher number indicated a better result. Co-morbidities and infection data were collated from Hospital records. Results: At 2 years post-op there were 5 deceased patients,17 did not have accessible radiographs and there was a 65% response rate to questionnaires. 46 patients were included in the final study group with a mean age of 45 (16-90). There was 1 Weber A fracture, 26 Weber B, 16 Weber C and 3 Medial malleolus fractures. 7% had Diabetes Mellitus, 22% were smokers. The mean OMAS score was 71.4(SD26.9) and LEFS score 56.7(SD25.9). There was no significant difference in PROM scores when fracture fragment reduction was optimised. There was a significant improvement in PROMs with low medial clear space and high tibiofibular overlap. Conclusion: This study reports a good correlation between quality of reduction and favourable PROMs at 2 years post ORIF ankle fracture. Reduced medial clear space and increased tibiofibular overlap were most associated with good outcome scores. Anatomical reduction of fracture fragments did not appear to affect PROMs on its own. There was very little infection in this cohort to confound the results. We would advise careful consideration of medial clear space and tibiofibular overlap in particular at time of fixation of unstable ankle fractures.