Does a rupture of the lateral ankle ligament need to be repaired in supination-adduction type II (OTA/AO 44A2) fractures?

PURPOSE

To evaluate the outcomes of patients with supination-adduction (SAD) type II (OTA/AO 44A2) fractures who had a lateral ankle ligament rupture repaired compared with patients who did not have a lateral ankle ligament repaired using patients who underwent fibula fracture fixation as a control group.

METHODS

A retrospective analysis of all 104 patients diagnosed with SAD type II fractures from January 2011 to December 2020 and managed operatively was performed. The patients were divided into three groups: 32 patients with ruptures of the lateral ligaments that were not repaired (group A), 34 patients with ruptures of the lateral ligaments that were repaired (group B), and 38 patients with fibula fracture fixation acting as the control group (group C). The objective outcomes including radiographic findings, the ankle range of motion, the manual ankle stress tests, and complications were gained from the record of the last time in outpatient clinics. The functional outcomes including the identification of functional ankle instability (IdFAI) scores were collected postoperatively at 12-month intervals to assess clinical outcomes. The Manchester Oxford Foot Questionnaire (MOXFQ) and Karlsson scoring scale were also recorded at the last follow-up.

RESULTS

The mean follow-up of the objective and subjective functional outcomes was 23.4 (range, 13-42) and 76.9 (range, 25-134) months, respectively. There was no significant difference in the radiographic findings, the ankle range of motion and complications between the three groups. All ankles were found to be stable using the manual ankle stress test in both group A and group B. The IdFAI scores showed a significant difference between group A and group B (1.12 ± 1.3 vs 0.35 ± 0.69; p < 0.001) in the first year of follow-up and no significant difference after the first year. No differences were noted in MOXFQ scores or Karlsson scores among the groups.

CONCLUSION

Directly repairing the lateral ligament could minimize the proportion of the first year of postoperative functional ankle instability, although the final stability of the ankle and clinical outcomes were not significantly different in SAD type II fractures.

LEVEL OF EVIDENCE

Level III, retrospective comparative case series.