Comparison of deltoid ligament repair and syndesmotic fixation in malleolar fractures

Introduction: The aims were to assess residual deltoid ligament instability after lateral malleolus osteosynthesis and to compare the outcomes of deltoid suture and syndesmotic fixation. Methods: A consecutive series of 65 eligible patients with a displaced or minimally displaced fibula fracture identified on a stress radiograph were prospectively enrolled. The patients were randomized into two groups, namely, group I (deltoid repair) and group II (syndesmotic fixation). We assessed the competence of the deltoid ligament intraoperatively using a manual stress test. Only the patients with residual medial instability (Medial Clear Space greater than 4 mm) were randomly assigned for treatment by deltoid ligament repair with anchor or syndesmotic fixation. Results: Of all the patients, 60 (92.2%) had positive preoperative manual stress test results. After fracture osteosynthesis, the test results were still positive in 13 (21.6%) patients, 8 (13.3%) patients from group I, both superficial and deep layers sutured with a bone anchor, and 5 patients (8.3%) from group II, stabilized with a syndesmotic 4-cortical screw. At the end of the surgery, a new manual stress test was performed, which proved stability in all the patients. The average follow-up period was 23.5 months. In groups I and II, the AOFAS scores were 95 and 93, the EQ-5D measures were 0.758 and 0.743, the visual analogue scale (VAS) scores were 16.7 and 19.2, and the Medial Clear Space values were 2.7 ± 0.5 mm and 2.6 ± 0.4 mm, respectively, without statistically significant differences. Conclusion: In 21.6% of cases, residual medial instability persisted after osteosynthesis of the lateral malleolus. The deltoid repair and syndesmotic fixation groups showed similar functional and radiological outcomes. Level of Evidence II; Therapeutic Studies; Prospective Comparative Study.