Factors Influencing the Outcomes of a Validated Return to Sports Test Battery After ACL Reconstruction: A Retrospective Analysis of 676 Patients (187)

OBJECTIVES: Second ACL injuries (defined as a graft rupture or contralateral ACL rupture) are common after ACL reconstruction. It is postulated that this observation could reflect a premature attempt to return to sports (RTS) and that delaying RTS until certain quality indicators or rehabilitation milestones are met could reduce the risk. There is consequently considerable interest in the application of RTS criteria. Multiple authors have reported that patients who passed a battery of tests prior to RTS, had a lower risk of re-injury and an increased rate of return to sport. However, factors influencing RTS scores have not been well studied. Therefore, the aim of this study was to determine the key factors that influence RTS test scores. METHODS: A retrospective analysis of consecutive patients who underwent primary ACL reconstruction between March 2016 and May 2017, who also had a documented RTS evaluation with K-STARTS, (a validated, composite psychological and functional RTS test battery (Fig 1)) at 6 months following surgery, was undertaken. All patients underwent the same standardized rehabilitation program (Table 1) but in addition to this they were offered the opportunity to participate in a separate individualized RTS program (Table 2). If patients chose to participate in the RTS program, this would occur in addition to the standard program and not instead of it. The first session would typically occur 3 months post-operatively and comprised of ten sessions that took place over a 12-week period. Demographic data and characteristics including the frequency of pre-injury sports participation, Tegner score, time from injury to surgery, graft type, the presence of meniscal lesions, whether a lateral tenodesis was performed, and whether patients participated in the specific RTS program in addition to physiotherapy were recorded. To identify factors influencing the K-STARTS score at six months postoperatively, an analysis of variances was performed. When a significant effect was found, post hoc comparisons were made using Tukey’s HSD tests with Bonferroni’s correction. RESULTS: 676 patients were included in the study. Outcomes of the analysis of the influence of factors on the K-STARTS score is comprehensively presented in Table 3. The K-STARTS score was significantly higher in males than females (13.9 vs 12.4, p<0.001), in younger patients (those aged less than 30 vs older patients, 14.2 vs 12, p<0.001), ACL reconstructions performed with hamstring tendon autografts compared to bone-patellar tendon-bone (13.5 vs 13.1, p=0.03) and in those who completed a specific RTS program in addition to standard rehabilitation, compared to those who did not participate (17.1 vs 13.1, p<0.001). However, the only factor that significantly influenced the K-STARTS score beyond the minimal detectable change threshold (previously determined to be 3.3 points) was the completion of the additional RTS program. The pre-injury frequency of sports participation, whether the dominant limb was injured, time from injury to surgery, the presence of associated meniscal injuries and whether a lateral tenodesis was performed, did not significantly influence the K-STARTS score. CONCLUSIONS: Completion of a specific return to sports program, in addition to standard rehabilitation, was the most important factor influencing the K-STARTS composite functional and psychological return to sports test score at 6 months after ACL reconstruction.