Long-term patient-reported outcomes comparing unstable ankle fractures with and without a posterior malleolus fracture

Aims: The aim of this study was to report the long-term patient-reported outcomes of unstable ankle fractures with a posterior malleolus fracture (PMF) and without (N-PMF). Methods: This retrospective study identified all adult patients (aged ≥ 16 years) presenting to a single large academic trauma centre between January 2009 and December 2012 with an unstable ankle fracture requiring surgery. The primary outcome measure was the Olerud and Molander Ankle Score (OMAS) at a minimum of ten years postoperatively. Secondary outcomes included the Manchester-Oxford Foot and Ankle Questionnaire (MOXFQ) index, EuroQol-five-dimension three-level questionnaire (EQ-5D-3L), EuroQol visual analogue scale (EQ-VAS), and complication rates. Results: Of 981 patients, 343 responded to questionnaires (35%). The mean age was 48.5 years (16.3 to 78.4) and 66% (n = 226) were female. Of these, 63.5% (n = 218) had a PMF and 11% of these (n = 23 of 218) were managed with fragment-specific fixation. No preoperative CT scans were performed. There was no difference between the groups with regard to infection (4% (n = 5) vs 5% (n = 11); p = 0.658) or further surgery (3.2% (n = 4) vs 2.8% (n = 6); p > 0.999). At a median of 13.1 years (IQR 12 to 14) the median OMAS was 85 (IQR 65 to 100). There was no clinical or statistical difference in the OMAS between N-PMF and PMF groups (87.5 (IQR 65 to 100) vs 85 (IQR 65 to 100); p = 0.622). No statistical or clinically meaningful differences were found in the MOXFQ index (p = 0.869), EQ-5D-3L (p = 0.787), and EQ-VAS (p = 0.558) between the groups. Complications requiring further surgery (p = 0.002) and post-traumatic osteoarthritis (p < 0.001) were found to be the only independent predictors of OMAS for all patients. Conclusion: In this large group of patients with surgically managed unstable ankle fractures, no preoperative CTs were carried out, and only 11% of PMFs underwent specific fixation. Despite this, the long-term patient-reported outcome measures and complication rates were comparable with those without a PMF.