The evolution of patient-reported outcome measures after a first lateral ankle sprain: A prospective study

Purpose: A lateral ankle sprain is the most common musculoskeletal injury in the physically active population. However, it is unclear how the clinical condition evolves during the period after the injury and what proportion of patients develops chronic symptoms. Therefore, the purpose of this study is to assess the evolution of patient-reported outcome measures after a first time lateral ankle sprain. Methods: A prospective clinical study assessed the patient-reported outcome measures (PROMs) of a consecutive group of 100 patients during 1 year after a first lateral ankle sprain. The Karlsson score and Foot and Ankle Outcome Score (FAOS) were assessed at 6 weeks, 3 months, 6 months, 9 months and 1 year. The Cumberland Ankle Instability Tool (CAIT)-score was assessed at 6 months, 9 months and 1 year. The difference between the time points of all scores was analysed using the positive change over time (binomial test versus 50%) and the difference in score (signed rank test). The time to sustained excellent level was also assessed overall and in several subgroups: age, gender, degree of injury (2 or 3), avulsion fracture, use of crutches, use of cast. Differences between subgroups were assessed by a generalized log-rank test. Results: All clinical scores demonstrated an improvement up to 12 months after the sprain. The median Karlsson score (interquartile range) improved from 62 (50-80) at 6 weeks to 90 (72-100) at 3 months, to 97 (82-100) at 6 months to 100 (90-100) at 9 months, to 100 (100-100) at 1 year. The analysis of positive change over time demonstrated a significant positive change (P-value < .0005) between all time points except between 6 weeks and 12 weeks when using the FAOS quality score. The difference in score demonstrated a significant change (P-value < .01) between all time points except between 36 weeks and 48 weeks when using the FAOS pain and FAOS sports score. Age and presence of an avulsion fracture were correlated with a slower recovery and worse results. At 1 year, in total 13 patients (13%) had a worse outcome corresponding to a Karlsson score < 81 or CAIT score < 24. Conclusion: The clinical condition after a first ankle sprain demonstrated a significant improvement in PROMs between the different time points in the first year. Twelve months after a first lateral ankle sprain 13% had a fair or poor outcome. Higher age and presence of an avulsion fracture were correlated with a slower recovery and worse results. This information is useful in clinical practice to predict further progression and inform patients. Moreover, it is valuable to improve treatment strategies. Level of evidence: Level II (prospective cohort study) (c) 2024 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.