Editorial Commentary: Nonanatomic Lateral Extra-Articular Procedures Performed at the Time of Anterior Cruciate Ligament Reconstruction Risk Overconstraint: Anatomic Anterolateral Ligament Reconstruction Does Not.

Abstract

Isolated anterior cruciate ligament reconstruction is associated with a risk of graft rupture that is more than 5-fold higher than that of combined anterior cruciate ligament-anterolateral ligament (ALL) reconstruction at a mean follow-up of greater than 100 months. However, biomechanical and clinical studies report that overconstraint is a concern with nonanatomic lateral-sided reconstruction. In fact, the normal biomechanics of the native ALL are anisometric. The ligament is tight in extension (providing rotational control) and slack in flexion (allowing physiological internal rotation). The ALL femoral attachment is proximal and posterior to the lateral epicondyle. The tibial tunnel or tunnels are located anterior to the fibular head and posterior to the Gerdy tubercle. An ALL graft must lie deep to the iliotibial band and superficial to the lateral collateral ligament. Fixation is performed in extension and neutral rotation. A single- or double-strand technique may be used. Surgeons performing lateral extra-articular procedures must understand the technical pitfalls that can lead to overconstraint and must seek to avoid them. Overconstraint can occur for a number of reasons, including the use of nonanatomic reconstruction and technical errors in tensioning, fixation angle, and tunnel positioning.