Instability following ACL rupture: What do we need to restore during reconstruction

ACL injury involves sagittal plane and rotatory instability; with its reconstruction aimed at restoring this instability. There remains room for improvement in long-term clinical outcomes and preventing recurrent instability. Therefore, it is important to understand the biomechanical parameters that require attention during reconstruction to optimize patient outcomes. In the setting of ACL injury, the armamentarium of the orthopaedic surgeon includes multiple physical examination maneuvers, quantitative measures of knee instability, and advanced imaging to determine the pattern of instability and inform surgical planning. The pivot shift phenomenon, as a measure of rotatory instability, is one of the key biomechanical parameters which must be restored after reconstruction and which is not fully restored by non-anatomic ACL reconstruction. Anatomic ACL reconstruction represents the “gold-standard”, as it has demonstrated enhanced ability to restore rotatory instability, reduce anterior tibial translation, and improve patient reported outcomes compared to non-anatomic techniques. Repair of concurrent ligamentous and meniscal injuries, as well as possible extra-articular procedures, may enhance the restoration of rotatory stability. Lateral extra-articular tenodesis may be indicated in patients with high pivot shift, who play sports with aggressive rotatory motion, or who have generalized laxity. This article details the approach to knee instability following ACL rupture and the optimal techniques to restore the rotatory stability post-reconstruction.

Duke Scholars

Author Robert Theodore Tisherman Orthopaedic Surgery