Three-dimensional kinematics of the tibiofemoral joint in ACL-deficient and reconstructed patients shows increased tibial rotation

The study of the altered knee joint movement patterns that follow anterior cruciate ligament (ACL) rupture can be very insightful in the development of prevention and therapeutic strategies concerning this injury. This can be achieved through three-dimensional kinematic analysis, because it provides an objective evaluation in vivo of the knee joint function. It has been demonstrated that ACL-deficient patients develop functional adaptations (ie, quadriceps avoidance gait) and walk with the knee in a more extended position to compensate for the ACL loss. Furthermore, it has been shown that ACL rupture results in anterior tibial translation and excessive tibial rotation while performing everyday activities. Although anterior tibial translation is restored with ACL reconstruction, tibial rotation seems to be restored only during low-demanding activities, whereas it remains increased during high-demanding activities. A possible explanation for the lack of restoration of tibial rotation to normal levels is the absence of complete reinstatement of the actual anatomy of the ACL. Reconstruction techniques should become more anatomic and try to approximate both ACL bundles. Two-bundle reconstruction may have advantages over single-bundle reconstruction, with respect to regaining a structure that morphologically and functionally better resembles a normal ACL. This technique however, has not been investigated dynamically, and future research should be performed. Therefore, long-term follow-up studies should focus on the advantages and disadvantages of different surgical procedures, whether it is the graft material or the tunnel positioning, so that dynamic knee function is restored and future pathology of the knee joint is prevented.