Purpose: There is a lack of consensus regarding the appropriate criteria for releasing patients to return to sports (RTS) after anterior cruciate ligament reconstruction (ACLR). A test battery was developed to support decision-making.
Methods: Twenty-eight patients (22 males and 6 females) with a mean age of 25.4 ± 8.2 years participated and were 6.5 ± 1.0 months post-ACLR. All patients followed the same rehabilitation protocol. The test battery used consisted of the following: isokinetic test, 3 hop tests and the jump-landing task assessed with the LESS. The isokinetic tests and single-leg hop tests were expressed as a LSI (involved limb/uninvolved limb × 100 %). In addition, patients filled out the IKDC and ACL-Return to Sport after Injury (ACL-RSI) scale. RTS criteria to pass were defined as a LSI > 90 % on isokinetic and hop tests, LESS < 5, ACL-RSI > 56 and a IKDC within 15th percentile of healthy subjects.
Results: Two out of 28 patients passed all criteria of the test protocol. The pass criterion for the LESS < 5 was reached by 67.9 % of all patients. For the hop tests, 78.5 % of patients passed LSI > 90 % for SLH, 85.7 % for TLH and 50 % for the SH. For the isokinetic test, 39.3 % of patients passed criteria for LSI peak torque quadriceps at 60°/s, 46.4 % at 180°/s and 42.9 at 300°/s. In total, 35.7 % of the patients passed criterion for the peak torque at 60°/s normalized to BW (>3.0 Nm) for the involved limb. The H/Q ratio at 300°/s > 55 % for females was achieved by 4 out of 6 female patients, and the >62.5 % criterion for males was achieved by 75 %. At 6 months post-ACLR, 85.7 % of the patients passed the IKDC score and 75 % the ACL-RSI score >56 criteria.
Conclusion: The evidence emerging from this study suggests that the majority of patients who are 6 months after ACLR require additional rehabilitation to pass RTS criteria. The RTS battery described in this study may serve as a framework for future studies to implement multivariate models in order to optimize the decision-making regarding RTS after ACLR with the aim to reduce incidence of second ACL injuries.
Level of evidence: III.
Keywords: Anterior cruciate ligament reconstruction; Hop tests; Injury risk; Questionnaires; Return to sports; Second injury; Strength.