Nonoperative Management of High Ankle Sprains: A Case Series With ≥18-Year Follow-up.

Background: High ankle sprains are common athletic injuries and can be associated with long-term sequelae. Regardless of operative or nonoperative treatment, there is a paucity of data in the literature about the long-term outcomes of high ankle sprains.

Hypothesis: Nonoperative treatment of high ankle sprains utilizing a standardized protocol will result in good long-term outcomes.

Study design: Case series; Level of evidence, 4.

Methods: Patients who experienced a high ankle sprain without radiographic diastasis of the syndesmosis were identified from a previous study database and contacted for long-term follow-up. All patients were high school or National Collegiate Athletic Association Division IA athletes at initial injury and were treated nonoperatively with the same standardized protocol. Patients completed a questionnaire that included documentation of any interim ankle injuries, 2 different patient-reported outcome scores, and ankle radiographs to conduct Kellgren-Lawrence scoring for ankle osteoarthritis.

Results: In total, 76 cases in 74 patients were identified in the database. A total of 40 patients were successfully contacted, and 31 patients (24 collegiate and 7 high school athletes) with 33 high ankle sprains completed the survey (31/40; 77.5%). The mean age at follow-up was 45 years (range, 34-50 years), with a mean time from injury to follow-up of 25 years. Overall, 93.5% (n = 29) of the respondents were male, and 42% (n = 13) of the respondents reported an ipsilateral ankle injury since their initial injury, with 16% (n = 5) having ankle or Achilles surgery. The mean Patient-Reported Outcomes Measurement Information System-10 score was 53.4 (SD, 8.3; range, 37.4-67.7), PROMIS median (IQR), 54.1 (39.9, 68.3), and the mean Self-reported Foot and Ankle Score score was 42.7 (SD, 5.86). Follow-up ankle radiographs were obtained in 11 (35%) of the respondents; 27% had Kellgren-Lawrence grade >2 osteoarthritis, and 36% had signs of heterotopic ossification on imaging. The mean tibiofibular clear space was 4.5 mm, and the mean tibiofibular overlap was 7.15 mm, with 27% of patients demonstrating some tibiotalar narrowing.

Conclusion: At long-term follow-up, nonoperative management of high ankle sprains without diastasis on imaging was associated with acceptable patient-reported functional outcomes and low rates of subsequent ankle injuries. There was a high incidence of arthritis, but most cases were not clinically significant. This case series shows the natural history of nonoperatively treated high ankle sprains and may serve as a comparison for different management techniques in the future.