Predictors of Return to Sports Following the Modified Broström Procedure for Chronic Ankle Instability

<b>Background/Objectives</b>: Despite a substantial duration of recovery following the modified Broström procedure (MBP), many individuals do not entirely recover their preinjury sports performance. Return to sports (RTS) can be affected by multiple elements apart from a patient's motivation. This study aimed to investigate the factors influencing RTS after anatomical ligament repair for chronic ankle instability. <b>Methods</b>: Sixty-two patients aged under 35 who underwent the MBP were regularly monitored for up to 3 years. Of these, 51 patients (82.3%) returned to their preinjury level of sports activity (return group), while 11 patients (17.7%) complained of partial or significant limitations (non-return group). Clinical outcomes were measured by the Foot and Ankle Outcome Score (FAOS) and the Foot and Ankle Ability Measure (FAAM). Mechanical stability was examined through physical examination and stress radiography. Peroneal strength was evaluated with an isokinetic dynamometer. Static and dynamic postural control abilities were tested using Biodex posturography. <b>Results</b>: Significant group differences were found in FAOS pain (94.7 points in the return group vs. 85.1 points in the non-return group; <i>p</i> = 0.004) and sports (91.2 vs. 78.8 points; <i>p</i> < 0.001) subscales. In the FAAM, the sports activity subscale also showed significant disparities (90.5 vs. 77.4 points, <i>p</i> < 0.001). Mechanical instability recurred in 2 patients (3.9%) in the return group and 4 patients (36.4%) in the non-return group, indicating a significant difference (<i>p</i> < 0.001). No notable differences were identified in stress radiography values or peroneal strength measurements. Posturographic evaluation showed that static postural control ability (overall stability index) did not differ significantly between the groups (1.22 in the return group vs. 1.43 in the non-return group); however, dynamic postural control ability differed substantially (1.41 vs. 2.33, <i>p</i> = 0.002). <b>Conclusions</b>: Residual pain, recurrence of mechanical instability, and insufficient recovery of dynamic postural control ability were associated with the return to preinjury level of sports activity after the MBP. Comprehensive rehabilitation protocols should address these factors to facilitate optimal postoperative sports participation.