Slope Increasing Medial Opening Wedge Proximal Tibial Osteotomy for Preventive Offloading of the Posterior Cruciate Ligament and to Correct Varus Malalignment in the Setting of a Failed Posterior Cruciate Ligament Reconstruction.

Abstract

The primary role of the posterior cruciate ligament (PCL) is to prevent posterior tibial translation (PTT). PCL graft forces increase as the posterior tibial slope decreases. Therefore, in the setting of a failed PCL reconstruction, the posterior tibial slope should be evaluated as a potential factor to offload the PCL graft. Patients with a failed PCL reconstruction or chronic PCL instability have an additional risk of meniscal tear and osteoarthritis (OA) development. PCL reconstruction failures may be associated with a decreased tibial slope and varus malalignment, which further increases the risk of subsequent meniscal and cartilage injuries. A slope increasing medial opening-wedge proximal tibial osteotomy (MOWPTO) has been shown to slow progression of medial knee OA, decrease the amount of PTT in the PCL-deficient knee, protect PCL reconstructions, and postpone the need for a total knee arthroplasty. A revision second-stage PCL reconstruction may be indicated to address ligament instability after the slope increasing MOWPTO heals, if the patient has symptomatic residual PTT. This Technical Note outlines the technique for a slope increasing MOWPTO to offload the PCL and to correct varus malalignment that may accelerate degenerative effects on the medial compartment in the setting of a failed PCL reconstruction and medial compartment OA.