Assessment of Post-Rehabilitation ACL Reconstructed Knees

Abstract

Background: Understanding objective measures of ACL-reconstructed knee function is important in determining the efficacy of rehabilitation protocols and a patient’s return to activities of daily living and sport activities. Objective: To assess the range of motion (ROM), isokinetic strength (torque) and functional performance measures (hop test) of ACL-reconstructed and ACL-intact knees. Methods: Twelve volunteers (5 females, 7 males) with unilateral ACL injury and reconstruction were given a battery of tests (hop test for distance, knee range of motion, knee extensor isokinetic testing to assess both affected and unaffected lower limb function, flexibility and strength. Main effects and interactions were analyzed by mixed-model repeated measures ANCOVA. Dependent variables included hop test for distance, knee flexion and extension range of motion, and knee extensor isokinetic torque. The independent variables were the intact/reconstructed ACL knee and time from surgery. Sex was the covariate. Results: No statistically significant differences (p>0.05) were found across all dependent variables hop test for distance (P = 0.939), knee flexion (P = 0.576) and extension (P = 0.431) ROM, and knee extensor torque (eccentric P = 0.923 and concentric P = 0.723) for the main effects and interactions of knee (ACL-reconstructed and ACL-intact) and time (0-12 months, 13-24 months, 25-36 months and 37+ months). The covariate, sex, did produce significant differences for the hop test (P < 0.0001) and isokinetic testing (eccentric peak torque P = 0.003 and concentric peak torque P=0.012). Conclusions: Clinicians may consider present rehabilitation protocols to be adequate in developing ROM and isokinetic strength following ACL reconstruction. However, greater improvements in ROM and strength may be achieved over an extended period following ACL reconstruction surgery.