Management of medial collateral ligament laxity.

Assessment of axial alignment with 3-foot radiographs and valgus-varus stress radiographs is important when managing symptomatic MCL instability. Realignment of the anatomical axis to 0 degrees to reduce the stress on the MCL reduces the symptomatic laxity. The assessment of MCL laxity is important when considering valgus HTO for medial compartment arthritis. A combined opening and closing wedge osteotomy reduces the size of the fragment needed and tensions the MCL at the same time. Interposition proximal tibial allografts may be used to retention combined MCL/LCL laxity as well as to correct associated deformities. As one would expect, defunctioning of the MCL in patients with valgus is best achieved using a varus distal femoral osteotomy.