ISAKOS: 2019 Congress in Cancun, Mexico

2019 ISAKOS Biennial Congress Paper #78


ACL-SPORTS Randomized Control Trial 1- and 2-Year Clinical and Functional Outcomes in Women: 100% Return-to-Sport Rates and High Outcome Scores, but No Between Group Differences

Jacob J. Capin, PT, DPT, MS, Newark, DE UNITED STATES
Celeste Dix, PT, DPT, MS, Newark, DE UNITED STATES
Angela H. Smith, DPT, Newark, DE UNITED STATES
Jessica L. Johnson, DPT, Newark, DE UNITED STATES
Amelia J. H. Arundale, PT, DPT, SCS, Newark, DE UNITED STATES
Ryan Zarzycki, PT, DPT, Newark, DE UNITED STATES
Lynn Snyder-Mackler, PT, ScD, FAPTA, Newark, DE UNITED STATES

University of Delaware, Newark, DE, UNITED STATES

FDA Status Not Applicable


The addition of perturbation training did not provide further benefit, but the strength, agility, plyometric, and prevention training among female athletes in the ACL-SPORTS randomized control trial resulted in exceedingly high strength, function, and patient-reported outcome measures; 100% returned to sport, 87% at their pre-injury level, by 2 years after ACL reconstruction.



Outcomes after anterior cruciate ligament (ACL) injury and ACL reconstruction (ACLR) are not uniformly good and are worse among young female athletes. Developing and evaluating rigorous rehabilitation and return-to-sports training programs are essential for improving outcomes. We developed the Anterior Cruciate Ligament Specialized Return-to-Sports (ACL-SPORTS) randomized control trial to test the effect of strength, agility, plyometric, and secondary prevention (SAPP) exercises with and without perturbation (neuromuscular) training (SAPP+PERT). The purpose was to compare SAPP versus SAPP+PERT training on return-to-sport rates and strength, functional performance, and patient-reported outcomes in female athletes 1 and 2 years after ACLR.


This study was a prospective randomized control trial (NCT01773317); IRB approval and informed consent were obtained. According to our a priori power analysis calculations, we needed 36 participants. We enrolled 39 female athletes between 3 and 9 months after primary ACLR when they had achieved at least 80% quadriceps strength, minimal to no effusion, full knee range of motion, and initiation of a running progression. Athletes were excluded if they had a previous ACL injury or lower extremity surgery, had a concomitant grade III knee ligament injury or large (>1cm^2) osteochondral defect, were not age 13-55 years, or did not participate regularly (50 hrs/yr) in jumping, cutting or pivoting sports. Participants were randomized to receive SAPP or SAPP+PERT training; they subsequently completed 10 training sessions (~2x/week). Athletes were tested 1 and 2 years after primary ACLR on clinical and functional measures including: isometric quadriceps strength index (QI) using an isokinetic dynamometer with the knee flexed to 90°; limb symmetry index on 4 single-leg hop tests (single, triple, crossover, and timed 6-meter); Knee Outcome Survey–Activities of Daily Living Subscale; Global Rating Score; and the International Knee Documentation Committee 2000 subjective score. Between group comparisons at 1 and 2 years were made using independent t-tests (a=0.05). We also calculated the proportion of athletes in each group who had returned to sport (at any level and their self-reported pre-injury level) by 2 years, comparing groups using Fisher’s Exact tests (a=0.05). Baseline characteristics were similar between groups.


All athletes (39/39, 100%) had returned to sport by 2 years, including 87% (34/39) at their self-reported pre-injury level (SAPP: 19/20 and SAPP+PERT: 15/19, p=0.182). There were no between group differences in return-to-sport rates. There were no significant or clinically meaningful differences between the SAPP and SAPP+PERT groups at either time-point for QI (1yr: SAPP: 99%, SAPP+PERT: 100%; 2yr: SAPP: 105%, SAPP+PERT: 102%), single-leg hop tests (1yr: SAPP: 96-102%, SAPP+PERT: 98-103%; 2yr: SAPP: 98-101%, SAPP+PERT: 97-101%), or any patient-reported outcome measure, all superior to outcomes reported in the literature.


Among women in the ACL-SPORTS randomized control trial, SAPP and SAPP+PERT training led to similar, very high 1 and 2 year outcomes in strength, function, patient-reported measures, and return-to-sport rates. Athletes across groups had symmetric strength and hop tests, high patient-reported outcomes, and 100% return-to-sport rates by 2 years, supporting the benefit of the common elements of the return-to-sport training program.