Is there a correlation between the psychological ACL-RSI score and isokinetic and neuromuscular functional performance tests of the knee following primary anterior cruciate ligament reconstruction?

Abstract

The decision to allow an athlete to return to sport following anterior cruciate ligament (ACL) reconstruction should not only be based on the time since surgery. Physical and psychological readiness to return to sport are essential, and a premature return is a risk factor for recurrent tears. The ACL-Return-to-Sport-after-Injury (ACL-RSI) questionnaire quantifies the influence of psychological factors on the patient's ability to return to play. The main goal of this study was to determine the relationship between the ACL-RSI score and postoperative isokinetic and neuromuscular tests. An analysis of a prospective cohort was performed including athletes who underwent surgery between 2013–2016 for an isolated full-thickness ACL tear, with a healthy contralateral knee and a complete evaluation of their knee's functional performance by isokinetic and neuromuscular tests. The isokinetic tests were performed during flexion and extension at 3 angular velocities on a dynamometer to measure strength: quadriceps 60°/s and 240°/s for concentric movements, hamstrings 30°/s for eccentric movements. The neuromuscular assessment was based on single-limb hop tests. The main judgment criterion was the correlation between the ACL-RSI score at 6-month follow-up and the difference between the 2 knees for isokinetic and neuromuscular tests. The correlations were assessed using Pearson correlation coefficient ( r ). One hundred and eighty-two patients fulfilled the inclusion criteria, 132 men/50 women, mean age 28.7 ± 8.6 years including 4 (2.2%) professional and 89 (48.9%) competitive athletes. The mean follow-up was 6.5 ± 1.7 (4–12) months. The ACL-RSI score was positively and significantly but weakly correlated with the tests ( r = 0.15 to 0.18, P = 0.01 to 0.03). The ACL-RSI score was significantly higher in patients who returned to sport ( P = 0.0001). The ACL-RSI score at 6-month follow-up was significantly and positively, but weakly correlated to isokinetic and neuromuscular tests. This tool provides a good evaluation of the psychological factors involved in the return-to-sport.