Lateral Approach to the Posterior Talocalcaneal Joint
Lateral Approach to the Posterior Talocalcaneal Joint
The lateral approach to the posterior talocalcaneal joint exposes the posterior facet of the talocalcaneal joint more extensively than does the anterolateral approach. It is mainly used for arthrodesis of the posterior part of the talocalcaneal joint.
Position of the Patient
Place the patient supine on the operating table with a sandbag under the
buttock of the affected side to bring the lateral malleolus forward. Place a support on the opposite iliac crest, then tilt the table 20 to 30 degrees away from the surgeon to improve access still further. Exsanguinate the limb either by elevating it for 3 to 5 minutes or by applying a soft rubber bandage, then inflate a tourniquet (see Fig. 12-31).
Landmarks and Incision
Landmarks
The lateral malleolus is the subcutaneous distal end of the fibula. The peroneal tubercle is a small protuberance of bone on the lateral surface of the calcaneus that separates the tendons of the peroneus longus and brevis muscles. It lies distal and anterior to the lateral malleolus.
Incision
Make a curved incision 10 to 13 cm long on the lateral aspect of the ankle. Begin some 4 cm above the tip of the lateral malleolus on the posterior border of the fibula. Follow the posterior border of the fibula down to the tip of the lateral malleolus, and then curve the incision forward, passing over the peroneal tubercle parallel to the course of the peroneal tendons (Fig. 12-46).
Internervous Plane
No internervous plane exists in this approach. The peroneus muscles, whose tendons are mobilized and retracted anteriorly, share a nerve supply from the superficial peroneal nerve. The approach is safe because the muscles receive their supply at a point well proximal to it.
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Figure 12-46 Make a curved incision 10 to 13 cm long on the lateral aspect of the ankle.
Superficial Surgical Dissection
Mobilize the skin flaps minimally, taking care not to damage the sural nerve as it runs just behind the lateral malleolus with the short saphenous vein. Begin incising the deep fascia in line with the upper part of the skin incision to uncover the two peroneal tendons. The tendons of the peroneus longus and peroneus brevis muscles curve around the back of the lateral malleolus. The peroneus brevis tendon, which is closest to the lateral malleolus, is muscular almost down to the level of the malleolus itself (see Fig. 12-61).
Continue incising the deep fascia, following the tendons. The peroneus brevis is covered by the inferior peroneal retinaculum distal to the tip of
the fibula. Incise it in line with the tendon (Fig. 12-47). The peroneus longus is covered by a separate fibrous sheath of its own; incise that sheath in line with the tendon as well. These ligaments of the retinaculum must be repaired during closure to prevent tendon dislocation (Fig. 12-48). When both peroneal tendons have been mobilized, retract them anteriorly over the distal end of the fibula (Fig. 12-49).
Deep Surgical Dissection
Identify the calcaneofibular ligament as it runs from the lateral malleolus down and back to the lateral surface of the calcaneus. The ligament is bound closely to the capsule of the talocalcaneal joint. The joint itself is difficult to palpate and identify, and a small amount of subperiosteal dissection on the lateral aspect of the calcaneus usually is required before the joint can be located. Having identified the joint, incise the capsule transversely to open it up (Fig. 12-50; see Figs. 12-49, 12-62, and 12-63).
Dang
Nerves
The sural nerve is vulnerable when the skin flaps are mobilized. Cutting it may lead to the formation of a painful neuroma and numbness along the lateral skin of the foot, which, although it does not bear weight, does come in contact with the shoe. The nerve also is valuable as a nerve graft.
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Figure 12-47 Incise the deep fascia in line with the upper part of the skin incision. Continue the fascial incision distally, following the course of the tendons. Incise the inferior peroneal retinaculum, and expose the peroneal tendons.
How to Enlarge the Approach
Local Measures
To expose the bare lateral surface of the calcaneus, incise the periosteum over its lateral surface and strip it inferiorly by sharp dissection. To see the talus better, cut the calcaneofibular ligament and the capsule of the talocalcaneal joint superiorly to uncover its lateral border.
Exposure of the articular surfaces of the joint can be achieved only by inverting the foot. Forcible inversion does not open up the joint if the anterior part of the talocalcaneal (talocalcaneonavicular) joint remains intact.
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Figure 12-48 Incise the deep fascia in line with the upper part of the skin incision. Continue the fascial incision distally, following the course of the tendons. Incise the inferior peroneal retinaculum and expose the peroneal tendons.
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Figure 12-49 Mobilize the peroneal tendons, and retract them anteriorly over the distal end of the fibula. Identify the calcaneofibular ligament. Incise it transversely to open the capsule of the posterior talocalcaneal joint.
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Figure 12-50 Open the joint capsule to expose the posterior talocalcaneal joint.
Lateral Approach to the Calcaneus
The lateral approach to the calcaneus is primarily used for open reduction and internal fixation of calcaneal fractures. Such fractures are always associated with significant soft tissue swelling; it is critical to allow this soft tissue swelling to subside before surgery is carried out to reduce the risk of skin necrosis. An accurate assessment of the vascular status of the patient is critical before undertaking surgery. Diabetes, especially with associated neuropathy and smoking, are relative contraindications to this surgery approach. The indications for the surgical approach include the following:
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Open reduction and internal fixation of displaced calcaneal fractures
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Treatment of other lesions of the posterior facet of the subtalar joint and lateral wall of the os calcis
Position of the Patient
Place the patient in the lateral position on the operating table. Ensure that the bony prominences are well padded. Place the leg that is to be operated on posteriorly with the under leg anterior. Exsanguinate the limb either by elevating it for 3 to 5 minutes or by applying a soft rubber bandage. Inflate a tourniquet.
Landmarks and Incision
Landmarks
Palpate the posterior border of the distal fibula and the lateral border of the Achilles tendon. Next, identify the styloid process at the base of the fifth metatarsal bone, which is easily felt along the lateral aspect of the foot.
Incision
The skin incision has two limbs. Begin the distal limb of the incision at the base of the fifth metatarsal and extend it posteriorly, following the junction between the smooth skin of the dorsum of the foot and the wrinkled skin of the sole. Make a second incision beginning approximately 6 to 8 cm above the skin of the heel, halfway between the posterior aspect of the fibula and the lateral aspect of the Achilles tendon. Extend this second incision distally to meet the first incision overlying the lateral aspect of the os calcis (Fig. 12-51).
Internervous Plane
No internervous planes are available for use. The dissection consists of a direct approach to the subcutaneous bone.
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Figure 12-51 Begin the distal limb of the incision at the base of the fifth metatarsal and extend it posteriorly, following the junction between the smooth skin of the dorsum of the foot and the wrinkled skin of the sole. Make a second incision beginning approximately 6 to 8 cm above the skin of the heel, halfway between the posterior aspect of the fibula and the lateral aspect of the Achilles tendon. Extend this second incision distally to meet the first incision overlying the lateral aspect of the os calcis.
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Figure 12-52 Deepen the skin incision through subcutaneous tissue, taking care not to elevate any flaps. Distally dissect straight down to the lateral surface of the calcaneus by sharp dissection. Next, elevate a thick flap consisting of periosteum subcutaneous tissues and skin. The peroneal tendons will be elevated in this flap. Do not attempt to dissect out layers in this flap.
Superficial Surgical Dissection
Deep Surgical Dissection
Incise the periosteum of the lateral wall of the calcaneus and develop a full-thickness flap consisting of periosteum and all the overlying tissues. Stick to bone and continue to retract the soft tissue flap proximally. The peroneal tendons will be carried forward with the flap. Divide the calcaneofibular ligament to expose the subtalar joint. Continue the dissection proximally to expose the body of the os calcis as well as the subtalar joint. Distally expose the calcaneocuboid joint by incising its capsule. If at all possible, try not to cut into the muscle belly of abductor digiti minimi (Fig. 12-53).
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Figure 12-53 Continue to develop the anterior flap. Divide the calcaneofibular ligament to expose the subtalar joint. Continue the dissection proximally to expose the body of the os calcis as well as the subtalar joint. Distally expose the calcaneocuboid joint by incising its capsule.
Dang
Nerves
The sural nerve is vulnerable if the skin flap is too far proximal.
The soft tissues are vulnerable during this approach. The risk of skin necrosis can be minimized if the flap is elevated as a full-thickness flap because the skin derives its blood supply from the underlying tissues. Dissecting the skin flaps in this area, which has always been severely traumatized, is associated with a significant incidence of wound breakdown. Accurate assessment of the patient’s preoperative vascular status is critical. Most surgery in this area has to be delayed for a significant period of time to allow soft tissue swelling to diminish before surgery commences.