Lateral Approach to the Hind part of the Foot

Lateral Approach to the Hindpart of the Foot ‌

The lateral approach provides excellent exposure of the talocalcaneonavicular, posterior talocalcaneal, and calcaneocuboid joints. It permits arthrodesis of any or all these joints (triple arthrodesis).

Position of the Patient

Position the patient supine on the operating table. Place a large sandbag beneath the affected buttock to rotate the leg internally, and bring the lateral portion of the ankle and hindpart of the foot forward. Further increase internal rotation by tilting the table away from you. Exsanguinate the limb either by elevating it for 5 minutes or by applying a soft rubber bandage, and then inflate a tourniquet (see Fig. 12-31).

Landmarks and Incision

Landmarks

The lateral malleolus is the palpable distal end of the fibula. The lateral wall of the calcaneus is subcutaneous. It is palpable below the lateral malleolus.

To palpate the sinus tarsi, stabilize the foot, holding the calcaneus with one hand, and place the thumb of the free hand in the soft tissue depression just anterior to the lateral malleolus. The depression lies directly over the sinus tarsi.

Incision

Make a curved incision starting just distal to the distal end of the lateral malleolus and slightly posterior to it. Continue distally along the lateral side of the hindpart of the foot and over the sinus tarsi. Then, curve medially, ending over the talocalcaneonavicular joint (Fig. 12-39).

Internervous Plane

The internervous plane lies between the peroneus tertius tendon (which is supplied by the deep peroneal nerve) and the peroneal tendons (which are supplied by the superficial peroneal nerve).

Superficial Surgical Dissection

Do not mobilize the skin flaps widely, because large skin flaps may necrose. Ligate any veins that cross the operative field. Open the deep fascia in line with the skin incision, taking care not to damage the tendons of the peroneus tertius and extensor digitorum longus muscles, which cross the distal end of the incision (Figs. 12-40 and 12-41). Retract these tendons medially to gain access to the dorsum of the foot. Do not retract the peroneal tendons, which run through the proximal end of the wound, at this stage (Fig. 12-42).

Deep Surgical Dissection

Partially detach the fat pad that lies in the sinus tarsi by sharp dissection, leaving it attached to the skin flap; under it lies the origin of the extensor digitorum brevis muscle. Detach its origin by sharp dissection, and reflect the muscle distally to expose the dorsal capsule of the talocalcaneonavicular joint in the distal end of the wound and the dorsal capsule of the calcaneocuboid joint more laterally (Fig. 12-43). Incise these capsules and open their respective joints by inverting the foot forcefully (Fig. 12-44). Next, incise the peroneal retinacula and reflect the peroneal tendons anteriorly. Identify and incise the capsule of the posterior talocalcaneal joint. Open it by inverting the heel (Fig. 12-45).

Figure 12-39 Make a curved incision starting just distal to the distal end of the

lateral malleolus and slightly posterior to it. Continue distally along the lateral side of the hindpart of the foot and over the sinus tarsi. Then, curve the incision medially toward the talocalcaneonavicular joint.

Figure 12-40 Incise and open the deep fascia in line with the skin incision.

Figure 12-41 Take care not to damage the tendons of the peroneus tertius and the extensor digitorum longus, which cross under the distal end of the incision.

Figure 12-42 Retract the extensor tendons medially.

The talocalcaneonavicular, posterior talocalcaneal, and calcaneocuboid joints now are exposed. Note that, in virtually all cases in which this approach is used, these joints are in abnormal position. The approach should remain safe as long as it stays on bone while the joints are being identified.

Dang

Skin Flaps

Exposures in this area are notorious for producing necrosis of skin flaps. Therefore, skin flaps should be cut as thickly as possible, stripping and retraction should be kept to a minimum, and sharp curves in the skin

incision should be avoided.

How to Enlarge the Approach

Local Measures

To open the calcaneocuboid, talocalcaneonavicular, and posterior subtalar joints, invert the foot. Note that both the talocalcaneonavicular joint and the posterior subtalar joint must be incised before inversion will open either one.

Extensile Measures

To enlarge the approach proximally, continue the incision, curving it along the posterior border of the fibula. By developing a plane between the peroneal muscles and the flexor muscles, the entire length of the fibula can be exposed. In practice, however, this extension is required rarely, if ever.

The incision also may be extended posteriorly and proximally to reach the subcutaneous Achilles tendon.

Figure 12-43 Retract the fat pad with the skin flap. Detach the origins of the extensor digitorum brevis, and retract the muscle distally to expose the dorsal capsule of the talocalcaneonavicular joint in the distal end of the wound and the more lateral dorsal capsule of the calcaneocuboid joint.