Jump performance and hop function, kinesiophobia and return to sports are important prognostic factors for a subsequent injury after an anterior cruciate ligament reconstruction: A 2‐year follow‐up cohort study

PURPOSE: Finding prognostic factors for a subsequent injury after an anterior cruciate ligament (ACL) reconstruction. METHODS: We re-analysed the data of two intervention studies on adults with a hamstrings or quadriceps tendon ACL reconstruction. All participants were prospectively monitored for 24 months. At the end of the individual postsurgery rehabilitation, numerous self-reported and objective functional outcomes were quantified, all potential secondary injuries (primary outcome was the occurrence of secondary ipsi- or contralateral ACL injuries) and all rehabilitation and training measures were prospectively monitored. The association of potential factors with a secondary injury risk was determined using logistic mixed models. RESULTS: We included 148 participants (mean age 25.3 years standard deviation 5.1 years, 63 females). Eight participants had a subsequent ACL injury, among them seven ispilateral and one contralateral side ACL rupture. The final model for the likelihood of a subsequent ACL injury led to a sensitivity (correctly classified participants who had a subsequent ACL injury) of 83.3% and to a specificity (correctly identified participants without who did not have a subsequent ACL injury) of 100% (n = 93). The main contributing factors to subsequent ACL or any subsequent other injuries were: higher kinesiophobia values (odds ratio OR = 2.0, 95% confidence interval CI = 1.1-3.4), higher knee loading levels during activity (Tegner activity scale, OR = 29, 95% CI: 1.1-791), lower performance levels at the Balance front hop (OR = 0.13, 95% CI: 0.03-0.52), and higher dynamic valgus (knee separation distance in the frontal plane) during the landing of a drop jump landing (OR = 0.80, 95% CI: 0.65-0.98). CONCLUSION: Most of the predictive factors for a second subsequent injury after an ACL reconstruction are modifiable by adequate training and rehabilitation measures. The modification of these factors might decrease the secondary risk of injury risk. LEVEL OF EVIDENCE: Level II, a prospective cohort study.