Editorial Commentary: Anterolateral Hinge Position Decreases the Slope in Opening-Wedge High Tibial Osteotomy: A Key Point in Treating an Anterior Cruciate Ligament-Deficient, Varus Knee

The orthopaedic surgeon who performs opening-wedge high tibial osteotomy (HTO) has to be aware of the behavior of the tibial slope depending on variations in the location of the hinge and in the inclination of the osteotomy. The most important point is that changing both the inclination and the rotation axis of the osteotomy cut affects the tibial slope. There is a natural trend to unintentionally increase the tibial slope when performing an opening-wedge HTO. However, an increased tibial slope has been established as a risk factor for both primary and recurrent anterior cruciate ligament (ACL) injuries, whereas slope-reducing osteotomies decrease anterior tibial translation and protect the ACL graft. To reduce tibial slope in opening-wedge HTO, it seems more practical to internally rotate the osteotomy, establishing an anterolateral hinge, than to change the inclination of the cut, given that it seems more predictable and technically easier to perform internal rotation during surgery. Trying to achieve both internal rotation and extension increases the complexity of the osteotomy. Not every osteotomy needs to have an anterolateral hinge; in fact, decreasing the tibial slope would be a disadvantage in the posterior cruciate ligament-deficient knee. However, for the ACL-deficient knee with varus malalignment, aiming to decrease the tibial slope using an anterolateral hinge could be considered during preoperative planning.