REVISION ANTERIOR CRUCIATE LIGAMENT (ACL) RECONSTRUCTION OUTCOMES ARE SIGNIFICANTLY LOWER THAN PRIMARY ACL RECONSTRUCTION: WHAT SHOULD WE ADVISE OUR PATIENTS?

The increase in annual rates of ACL reconstruction (ACL-R) includes both primary and revision procedures. Similar to primary ACL-R, Revision ACL (Re-ACL) patients undergo surgery with the intent to improve function with daily activities including returning to sport or recreational activities. The primary purpose of this study was to compare the objective clinical, functional, and quality of life outcomes of patients following Re-ACL with a matched cohort of unilateral primary ACL-R, to facilitate improved counselling of patients regarding expected outcomes following surgery. Prospectively collected patient data from a single center was utilized for this study. Re-ACL and primary ACL-R patients were matched for sex, age at the time of surgery within 12-months, body mass index (BMI) within two kg and Beighton score. Patient demographics, injury, and operative data were collected. All patients completed functional assessment at 24-months post-operative including balance and hop testing. The anterior cruciate ligament quality of life questionnaire (ACL-QOL) was completed pre-operatively and 24-months post-operatively. Descriptive statistics, paired t-tests and one-way ANOVA were utilized to assess between group differences. A total of 470 patients were included, 235 each Re-ACL and ACL-R. There were 122 males and 113 females per group, mean age was 30.7 years, mean BMI was 25.3 kg/m2, and the median Beighton score was three. At 24-months post-operative graft failure occurred in 24/235 (10.2%), of the Re-ACL compared to 2/235 (0.9%) of the ACL-R cohort (p<.05). Laxity as assessed by positive Lachman and Pivot-shit tests was 66/235 (28.1%) and 36/235 (15.3%) respectively for Re-ACL compared with 38/235 (16.2%) and 11/235 (4.7%) for ACL-R (p<.05). Functional assessment indicated statistically significant differences in single leg balance and single-leg hop test performance with 108/235 (46%) achieving 90% limb symmetry for Re-ACL compared with 202/235 (86%) for ACL-R (p<.01). Rate of return to sport or activity was 54% for Re-ACL compared with 92% for ACL-R. The pre to post ACL-QOL scores improved from 29.5 to 61.3 for Re-ACL and 27.5 to 76.0 for ACL-R. One-way ANOVA demonstrated statistically significant between group differences in post-operative ACL-QOL scores, f = 55.3, p< .001. In this matched-cohort study comparing outcomes at 24-months post-operative, Re-ACL demonstrated statically significantly higher rates of failure and residual laxity, lower achievement of limb symmetry and return to sport, and lower disease-specific QOL. In counselling patients regarding Re-ACL surgery, strong consideration should be given to discussing clinical, functional and QOL outcomes to help manage patient expectations.