The kinetic compensation phenomenon: Contralateral knee overload after ACL reconstruction and the modulatory effect of lateral extra-articular tenodesis.
Rivarola H, Helito C, Palanconi M, Peñaherrera-Carrillo C, Barros Castro A, Endara Urresta F. · Journal of clinical orthopaedics and trauma · 2026
Background: Contralateral anterior cruciate ligament (ACL) injury remains one of the most frequent and devastating complications after primary reconstruction, occurring in up to 15% of athletes. Traditional return-to-sport (RTS) criteria fail to detect subtle kinetic and neuromuscular asymmetries that persist despite restoration of ligament continuity. These compensatory load-shifting mechanisms-collectively described as the Kinetic Compensation Phenomenon -may be quantifiable through a composite biomechanical index.
Methods: Two hundred sixteen competitive athletes underwent standardized single-leg hop and change-of-direction testing on dual force platforms synchronized with surface electromyography at 3, 6, and 12 months postoperatively. KCI was computed as the mean z-score of ΔVGRF, ΔLR, ΔTTS, and ΔCCI, scaled to a T-distribution (mean = 50, SD = 10). Predictive validity for contralateral ACL injury at 24 months was assessed using ROC and Cox proportional-hazard models.
Results: The LET group demonstrated significantly lower KCI values across follow-up (p
Conclusion: LET was associated with lower contralateral kinetic overload and more symmetric biomechanical profiles during functional testing. The KCI represents a promising composite index of functional readiness that may complement conventional RTS criteria; however, external validation is required before routine clinical implementation. Composite index of functional readiness that may complement conventional RTS criteria. Level of evidence II.