Activity and functional readiness, not age, are the critical factors for second anterior cruciate ligament injury — the Delaware-Oslo ACL cohort study. Issue 18 (11th February 2020)

• Record Type: Journal Article
• Authors: Grindem, Hege; Engebretsen, Lars; Axe, Michael; Snyder-Mackler, Lynn; Risberg, May Arna
• Is Part Of: British journal of sports medicine. Volume 54:Issue 18(2020)
• Page Start: 1099
• Page End: 1102
• Publication Date: 2020-02-11
• Subjects: anterior cruciate ligament -- anterior cruciate ligament reconstruction -- return to sport -- knee function -- knee injury; Sports medicine -- Periodicals; 617.1027
• DOI: 10.1136/bjsports-2019-100623
• Languages: English
• ISSNs: 0306-3674

Abstract

Abstract : Objective: To elucidate the relationships between age, return to level I sport (RTS) within the first postoperative year, passing RTS criteria and second anterior cruciate ligament (ACL) injury. Methods: In a prospective cohort study, 213 athletes were followed for 2 years after ACL reconstruction to record second ACL injuries. Independent variables were age, passing RTS criteria and level I RTS within the first postoperative year (vs later or no RTS). We defined passing RTS criteria as ≥90 on the Knee Outcome Survey — Activities of Daily Living Scale, global rating scale of function and quadriceps strength/hop test symmetry. Results: The follow-up rate was >87% for all outcomes. In multivariable analysis, level I RTS within the first postoperative year and passing RTS criteria were highly associated with second ACL injury (level I RTS HR: 6.0 (95% CI: 1.6 to 22.6), pass RTS criteria HR: 0.08 (95% CI: 0.01 to 0.6)), while age was not (age HR: 0.96 (95% CI: 0.89 to 1.04)). Athletes <25 years had higher level I RTS rates in the first postoperative year (60.4%) than older athletes (28.0%). Of those who returned to level I sport in the first postoperative year, 38.1% of younger and 59.1% of older athletes passed RTS criteria. Conclusion: High rates of second ACL injury in young athletes may be driven by a mismatch between RTS rates and functional readiness to RTS. Passing RTS criteria was independently associated with a lower second ACL rate. Allowing more time prior to RTS, and improving rehabilitation and RTS support, may reduce second ACL injury rates in young athletes with ACL reconstruction.