Abstract
Objective: Anterior cruciate ligament (ACL) graft failure or contralateral ACL injury after returning to sport (RTS) post-ACL reconstruction remains problematic. Re-injury prevention programs that "bridge" standard physical therapy and release to unrestricted sports participation can help. This observational study evaluated the characteristics of athletes who sustained an ipsilateral ACL graft or contralateral ACL injury after RTS bridge program participation. Materials and Methods: Comparisons were made between RTS bridge program participants who either had or had not sustained an ipsilateral ACL graft or contralateral ACL injury following RTS. Post-program objective physical function tests, pre- and post-program Knee Outcome Survey Sports Activity Scale (KOS-SAS), global sports activities knee function scores, sports activities knee function rating improvements, and post-program sport performance ability perceptions were evaluated. Results: A total of 204 athletes (19.7 ± 6 years of age, 108 males) completed the RTS bridge program and were released back to sports at 8.5 ± 2.3 months post-surgery. Groups had similar pre-morbid performance level restoration perceptions. Taller and heavier male athletes displayed greater single leg triple hop for distance magnitude, and quicker single leg timed hop, single leg timed crossover hop, and NFL 5-10-5 and NFL "L" times. Bilateral physical function test symmetry results did not differ between groups. By 7.8 ± 4 years post-surgery, 17 subjects sustained either ipsilateral ACL graft injury (n = 6) or contralateral ACL injury (n = 11), with a similar frequency between males and females (p = 0.30). Athletes who sustained an ipsilateral ACL graft or contralateral ACL injury were younger, and more often scored ≥ 25th percentile for post-program global sports activities knee function and KOS-SAS scores; more frequently had two-level overall sports activities knee function rating improvements; and tended to sustain this new knee injury during the initial RTS season. Conclusions: Factors other than physical function or performance capability may possess a strong influence on ipsilateral ACL graft or contralateral ACL injury following RTS bridge program participation.