The patient is placed in a supine position at the immediate edge of the operating table. A sandbag is placed under the ipsilateral hip to internally rotate the leg and improve exposure of the lateral aspect of the foot and ankle. The limb is prepared and draped appropriately to ensure adequate exposure. The foot and ankle are exsanguinated with an Esmarch elastic wrap, and a tourniquet is inflated on the upper third of the thigh. The surgeon operates from the foot of the table.

VIDEO 88.1 Tibiotalar Arthrodesis. Siddhant K. Mehta, MD; Nicholas A. Abidi, MD; Sheldon S. Lin, MD (6 min)

The following instruments and equipment should be on hand: microsagittal saw and/or osteotomes, curets/osteotomes, 7.3-mm cannulated screws, 4.0- or 4.5-mm cannulated screws, and plating systems (optional).

Numerous approaches and techniques exist to achieve a stable ankle arthrodesis.⁷ This section will focus on open ankle arthrodesis using a two-incision transfibular exposure and a transarticular cross-screw fixation technique supplemented with fibular-onlay strut grafting and anterior plating. The complete procedure can be seen in the video supplement.

Open ankle arthrodesis can be used for any patient but is particularly useful for patients with severe ankle joint deformity because it provides better visualization of the joint and improved access for bone resection, correction of deformity, and screw placement. It is performed through a two-incision transfibular exposure. The first incision is marked and made directly over the fibula, beginning approximately 10 cm proximal to the tip of the fibula and extending distally along the fibular shaft toward the base of the fourth metatarsal (Figure 2, A). This incision uses the internervous plane that lies between the peroneal muscles (superficial peroneal nerve) and extensors (deep
peroneal nerve) as the dissection is being performed down to subcutaneous bone. After the distal 10 cm of the fibula has been exposed, the superior peroneal retinaculum is incised posteriorly and the peroneal tendons are mobilized while the sural and superficial peroneal nerves are protected. The exposure is performed carefully to maintain full-thickness flaps and to identify and protect tendons and neurovascular structures.

The periosteum is stripped from the fibula anteriorly and minimally posteriorly using an osteotome or curet (Figure 2, B). The deep incision is then extended across medially to expose the distal tibia and the tibiotalar articulation and distally to expose the posterior facet of the subtalar joint and the sinus tarsi area. The soft tissue from the distal end of the tibia and the talar neck to the medial malleolus is stripped with a periosteal elevator.

An oscillating saw is used to create a fibular osteotomy approximately 4 to 6 cm proximal to the tip of the lateral malleolus while the soft-tissue attachments at the posterolateral aspect and distal end of the fibula are preserved (Figure 3, A). The syndesmosis is then débrided of intervening cartilage, soft tissues, and cortical bone, after which exposure of the tibiotalar joint can be enhanced. A sagittal cut of the fibula is made to resect the medial fibular fragment to be morcellized and used for autologous bone grafting (Figure 3, B). The remaining fibula is then turned down and away from the arthrodesis site to provide adequate exposure to the posteromedial aspect of the tibia (Figure 3, C). The blood supply to this lateral fibular fragment is maintained; because of the preserved ligamentous attachments, this fragment is later used as a fibular-onlay strut graft to serve as a lateral buttress.

Sharp dissection is used through the lateral incision to elevate the scarred ankle capsule and strip soft-tissue attachments from the joint both anteriorly and posteriorly. Retractors are placed as needed to expose the ankle mortise and protect soft tissues while bone cuts are made. The tibiotalar joint is then manually denuded of cartilage and subchondral cortical bone with curets and/or osteotomes. Following joint preparation, tibiotalar fusion alignment should be inspected directly and via fluoroscopic image intensification. Additional correction can be achieved using osteotomes or, if needed, autologous bone block placement.

One option (which we prefer not to perform because of its potential to “burn the bone”) is to create two flat surfaces. Using a broad osteotome or an oscillating saw, a cut perpendicular to the long axis of the tibia is made at the level of the apex of the dome of the articular surface, allowing removal of the tibial plafond. The cut should cross the ankle joint but stop just where the medial malleolus begins. The medial malleolus serves to provide an area of solid fixation for the lateral-to-medial screw and preserve the medial blood supply to the talus through the deltoid ligament.

Next, the foot is placed in proper alignment for arthrodesis. The talus is positioned so that the forefoot is in 5° to 10° of external rotation and the hindfoot is in 5° of valgus, with zero degrees of dorsiflexion and displacement so that the posterior margins of the talus and tibia are flush. A cut through the dome of the talus is then made parallel to the distal tibial cut, resecting approximately 3 to 5 mm of bone. The joint surfaces are brought together, and alignment is assessed. To correct for malalignment, further bony resection from the distal tibial end is performed.

The second incision is made after distal tibial and talar bony resection. Exposure of the medial malleolus is achieved through a longitudinal 6-cm anteromedial incision made along the anterior third of the medial malleolus, dissecting through subcutaneous tissue and fat while full-thickness flaps are maintained (Figure 4). The ankle capsule and periosteum are carefully removed. The remaining joint surfaces are inspected carefully for residual cartilage and sclerotic bone. All joint surfaces are drilled or curetted until bleeding bone is noted. The tibiotalar joint surfaces are apposed, and satisfactory alignment is obtained.