Digital Physiotherapeutic Ankle-Specific Training System for Patients With Chronic Ankle Instability Following Modified Brostrom Surgery: Noninferiority Randomized Controlled Trial at a Tertiary Grade A Trauma Center in China.

Background: Functional rehabilitation is commonly used for patients with chronic ankle instability (CAI). Digital training (DT) systems have become increasingly popular in postoperative rehabilitation; however, their effectiveness for CAI patients after modified Brostrom surgery (MBS) is uncertain. Furthermore, specialized physiotherapy resources for CAI are limited in some regions, highlighting the need for effective digital home-based rehabilitation alternatives. Objective: This trial aimed to evaluate whether individually tailored physiotherapeutic ankle-specific training (PAST) delivered via a DT system is noninferior to conventional face-to-face physiotherapy in clinical outcomes and to compare their cost-effectiveness in CAI patients following MBS in China. Methods: We conducted a 2-arm, single-blinded (assessor), noninferiority randomized controlled trial at a tertiary hospital in Shanghai, China, from January 2022 to January 2024. A total of 84 postsurgery CAI patients were randomly assigned to a DT group (n=42), which received a 12-week individualized PAST program via a digital system, or a physiotherapy group (n=42), which received standard face-to-face physiotherapy for 12 weeks. Assessments were performed at baseline, 12 weeks, and 24 weeks postoperatively. The primary outcomes were 2 subscales of the Foot and Ankle Ability Measure, with a noninferiority margin of 8 points for Foot and Ankle Ability Measure-Activities of Daily Living (FAAM-ADL) and 9 points for Foot and Ankle Ability Measure-Sports (FAAM-S). Secondary outcomes included balance tests (time-in-balance, foot-lift, and star excursion balance), functional tests (ankle dorsiflexion range of motion, side-hop, and figure-8 hop), and quality of life (FAAM questionnaire). We also collected intervention costs to evaluate cost-effectiveness. Statistical analyses included between-group comparisons of outcomes and nonparametric bootstrapping to calculate incremental cost-effectiveness ratios. Results: Baseline characteristics were similar between groups (except for a difference in foot-lift test performance). By the 24-week follow-up, improvements in the primary outcomes were comparable between the DT and physiotherapy groups, with adjusted between-group differences of 0.36 (95% CI -1.01 to 1.72) for FAAM-ADL and 1.67 (95% CI -0.61 to 3.96) for FAAM-S. These differences fell within the predefined noninferiority margins, demonstrating noninferiority of the digital program. No significant between-group differences were observed in secondary outcomes (all P>.05). The average cost per patient was lower in the DT group (CNY 53,551; an exchange rate of US $1=CNY 7 was applied) than in the physiotherapy group (CNY 59,372), yielding an incremental cost of CNY -14,451 in favor of the digital intervention. The bootstrapped incremental cost-effectiveness ratios were CNY -16,396 for FAAM-ADL and CNY -114,131 for FAAM-S, indicating that DT was more cost-effective. Conclusions: Individually tailored PAST delivered via a DT system was found to be clinically noninferior to conventional face-to-face physiotherapy and more cost-effective, supporting its use as a viable rehabilitation alternative for CAI patients after MBS.