Open Wedge High Tibial Osteotomy with Pes Anserinus Preservation and Insertion of Bone Substitutes

Biplanar open wedge high tibial osteotomy (OWHTO) has become common since the introduction of OWHTO-specific plates. However, the management of soft tissues, including skin, the pes anserinus, and the superficial medial collateral ligament (sMCL) release vary among surgeons. We introduce an OWHTO methodology that avoids pes incision and repair, uses bone substitute insertion into the opening gap and includes management of soft tissues to minimize complications. We adopted a reversed curved oblique incision to reduce the risk of saphenous nerve injury. We avoided pes incision, taking advantage of its posterior component force to allow it to function as a compressor of the ascending osteotomy site. The proximal component force of the pes provides compression between the bone substitute insertions and the proximal/distal cortices. This allows postoperative weight bearing to be distributed to the substitute, which may reduce the risk of implant failure. The sMCL is detached from the distal tibial attachment without cutting, enabling its return to its original position underneath the pes and to be repaired. This sMCL release with complete pes preservation may reduce the risk of deep infection or medial laxity during total knee arthroplasty conversion, and further reduce the risks of OWHTO.