The traditional sinus tarsi approach extends approximately 7–8 cm starting from the tip of the fibula to the base of the fourth metatarsal. This is extended through the skin and subcutaneous tissue down to the extensor digitorum brevis (EDB) fascia distally and sinus tarsi proximally. Care should be taken to observe and protect sensory branches of the superficial peroneal nerve dorsally and the sural nerve plantarly. The sinus tarsi fat may then be excised sharply or elevated superiorly to expose the anterior aspect of the subtalar posterior facet. The EDB muscle may be either split or dissected off the calcaneus and reflected anteriorly and superiorly. Inferiorly are the peroneal tendons, which should be protected throughout the procedure. In severe valgus deformity, these tendons may be contracted and require either lengthening or release. At this point, there should be excellent visualization of the subtalar and calcaneocuboid joints. If the joints are tight, then the use of a Cobb elevator will help to mobilize the joints and free up adhesions or capsular contractures. Following this, the use of a smooth tip lamina spreader will help to open up the subtalar joint from the lateral aspect. Once adequate mobility is achieved, a toothed lamina spreader may be placed more anterior in the sinus tarsi to allow easier access to the entire posterior facet for debridement with curettes and rongeurs down to the subchondral bone (Fig. 5.2). The calcaneocuboid joint is easily accessed by the use of a pin spreader with pins placed in the calcaneus and cuboid (Fig. 5.3). Because of the fairly flat configuration of the calcaneocuboid joint, a sharp osteotome is helpful to debride the remaining cartilage on both sides of the joint.

The most common approach to the talonavicular joint is a dorsomedial incision between the anterior and posterior tibial tendons. This is a safe approach, although one should take care to avoid injury to the saphenous vein and nerve. However, many prefer a more dorsal approach between the anterior tibial tendon and extensor hallucis longus tendons, which has been shown to provide easier, more complete access to the entire joint. Higgs et al. showed in a cadaveric study that the direct dorsal approach provided access to 92% of the talonavicular joint as opposed to 71% as provided by the traditional dorsomedial approach [8]. In most cases , the authors utilize the dorsomedial approach.

With the dorsomedial approach to the talonavicular joint, the incision extends from the medial malleolus toward the medial cuneiform. The subcutaneous tissues are bluntly divided in order to identify any crossing veins, which are commonly present and often sizable. Dissection can then be carried sharply over the dorsomedial aspect of the joint capsule, which can then be elevated dorsolateral and plantarmedial to expose the joint. If needed, this incision is extensile to the navicular-cuneiform joint and medial cuneiform; however, this access is limited by the anterior tibial tendon crossing over the medial cuneiform. A pin spreader is useful to distract the joint. The pin in the navicular should be aimed somewhat distal to avoid penetrating the joint which will inhibit access (Fig. 5.4). As noted previously, a Cobb elevator can be helpful to release the capsule laterally and allow better mobility of the joint. The joint can then be debrided with curettes and rongeurs. Take care to preserve the shape of the talar head as the underlying bone is often soft and it can be easy to over-resect.

The direct dorsal approach to the talonavicular joint exploits the interval between the anterior tibial and extensor hallucis longus tendons. Care should be taken to identify and mark the neurovascular bundle prior to exsanguination to avoid inadvertent injury. The incision is carried sharply through the skin, and attention should be paid to identifying a branch of the superficial peroneal nerve, which may cross directly over the talonavicular joint. Sharp dissection can then be carried down to the bone and capsule elevated medial and laterally. The use of a pin distractor provides excellent access to the joint. One additional benefit of this approach is that it is relatively easy to place a dorsal to plantar screw for the subtalar arthrodesis fixation .

A single incision, all medial technique, was described and popularized by Myerson and others for patients with severe pes planovalgus deformity. The purpose of this approach is to avoid the lateral incision and potential soft tissue compromise due to tension on surgical incision after correcting the deformity [9, 10]. When utilized for correction of a severe planovalgus deformity, this approach begins with a percutaneous release of the contracted peroneal tendons 10 cm above the tip of lateral malleolus. A medial-based incision is then performed beginning from the undersurface of medial malleolus, extending to the medial cuneiform, centered over the talonavicular joint. Dissection is carried through the skin and subcutaneous tissue with care taken to avoid injury to the deltoid ligament proximally, saphenous vein, and tibialis anterior tendon insertion distally. The talonavicular joint capsule is then incised sharply and dissected dorsally and plantarly providing access to the joint. Releasing the remnant of the posterior tibial tendon from the navicular will improve access. The subtalar joint is accessed by opening the posterior tibial tendon sheath and resecting the posterior tibial tendon. Opening the floor of the tendon sheath will give one access to the posterior facet of the subtalar joint. Placing a lamina spreader on the talar neck and medial calcaneus will allow access to the subtalar joint, which can be prepared with curettes and osteotomes. The talonavicular joint can then be accessed similar to the dorsomedial approach with utilization of a pin distractor and a Cobb elevator to develop capsular flaps dorsally and plantarly. As dissection is carried inferiorly, it is necessary to retract the flexor hallucis longus, flexor digitorum longus, and neurovascular bundle inferiorly in order to gain access to the calcaneocuboid joint. Preparation of the calcaneocuboid joint is the most challenging aspect of the single incision medial approach. This requires sharp release of the joint capsule and bifurcate ligament by feel after isolating the joint fluoroscopically. Distraction with a pin spreader or lamina spreader in the talonavicular joint allows access to calcaneocuboid joint . Preparation can then be carried out in standard fashion.