Relationships between Patient-Reported Outcomes and Predictors of Second ACL Injuries during Unanticipated Jump Landings.

Abstract

Background: Reactive and external visual-cognitive demands are prevalent in sport and likely contribute to anterior cruciate ligament (ACL) injury scenarios. However, these demands are absent in common return-to-sport assessments. This disconnect leaves a blind spot for determining when an athlete can return to sport with mitigated re-injury risk.

Purpose: To characterize relationships between patient-reported outcome measures (PROMs) and cognitive-task interference (i.e., cognitive demands exacerbating neuromuscular impairments) for biomechanical predictors of second ACL injuries during jump landings that involved rapid unanticipated decision making.

Methods: Thirty-six persons following primary ACL reconstruction (ACLR; 26 females/10 males, 19.8 ± 1.8 yr; 1.71 ± 0.1 m; 69.6 ± 12.8 kg, 1.5 ± 0.6 yr post-ACLR; Tegner: 6.8 ± 1.8) participated. PROMs of ACL-RSI and the Forgotten Joint Score-12 Knee (FJS-12) were selected to assess altered psychological state (e.g., confidence, attention toward knee). Jumping tasks under anticipated and unanticipated secondary jump directions were performed. Biomechanical variables were dual-task changes (unanticipated - anticipated) in 1) uninvolved limb hip rotator impulse (DTC_Uni-HRot_Imp), 2) asymmetry of knee extensor moment at initial contact (DTC_KEM_Asym), and 3) range of involved knee abduction angle (DTC_KAbA_Range). Regression models tested for relationships between PROMs and the dual-task change in biomechanical variables.

Results: ACL-RSI (DTC_Uni-HRot_Imp ( P < 0.001)) and FJS-12 (DTC_KAbA_Range ( P = 0.001)) had significant relationships with dual-task change in the opposite direction as expected (worse PROM ➔ less dual-task change). A follow-up analysis indicated that dual-task change was inversely correlated with the baseline estimates for kinetic biomechanical variables (less risky single-task biomechanics ➔ greater dual-task change for Uni-HRot_Imp and KEM_Asym).

Conclusions: The collective results are consistent with higher functioning participants (better PROMs) who also demonstrate desirable biomechanics during single-task conditions being prone to demonstrating the greatest risk-associated DTC in unanticipated scenarios.