The Chevron-type medial malleolar osteotomy has been described several times previously [19, 21]. The medial malleolus is exposed using a standard curvilinear medial incision, and a K-wire is then used to establish the apex of the Chevron cut. Under fluoroscopic guidance, the K-wire is advanced to the subchondral plate at the malleolar colliculous (Fig. 8.1). Proper angulation of the guidewire is necessary for exposing the OCL, and angulation can be adjusted based on the location of the lesion but should be around 30° in relation to the long axis of the tibia. Two parallel fixation holes are then drilled in the malleolus for later reduction of the fragment. An oscillating saw is then used to create the osteotomy, with a baby Bennett retractor in place to protect the posterior tibial tendon. Sawing is halted before reaching the articular surface and the osteotomy completed using an osteotome (Fig. 8.2). The procedure is concluded with reduction of the osteotomy fragment. This is achieved by securing predrilled fixation holes using 4.0 mm cannulated screws. A transverse screw is also placed in the malleolus to prevent superior migration (Fig. 8.3). A series of 62 patients undergoing Chevron-type osteotomy demonstrated satisfactory healing and fixation at a median time of 6 weeks. Fibrocartilaginous infill was evident in the superficial half of repair tissue at the osteotomy interface, and MRI indicated restored normal tissue in the deep half [21]. In a separate series, 4 of 19 patients had a slight (<2 mm) displacement at the osteotomy site, but this was attributed to technical error [9].

An oblique osteotomy provides adequate visualization of the talus and good congruity when executed properly [21, 37]. Some case series have shown no postoperative complications [27, 31], while others have reported osteoarthritis [17], reduction in plantar flexion [4], reduction in range of motion [4], loss of stability [21, 37], and potential for fragment migration when fixation screws are not applied perpendicular to the osteotomy cut [37]. Failure of the osteotomy to heal in an anatomic position may place higher load on the ankle, potentially leading to arthrosis [25]. Deciding which osteotomy is most appropriate to treat, medial OCLs should be based on the size and location of the lesion and most importantly on the surgeon’s experience with the technique.