Twelve

 

The Foot and Ankle

 

 

 

 

Ankle and Hindfoot

Anterior Approach to the Ankle

Anterior and Posterior Approaches to the Medial Malleolus Approach to the Medial Side of the Ankle

Posteromedial Approach to the Ankle Posterolateral Approach to the Ankle Lateral Approach to the Lateral Malleolus

Anterolateral Approach to the Ankle and Hindpart of the Foot Lateral Approach to the Hindpart of the Foot

Lateral Approach to the Posterior Talocalcaneal Joint Lateral Approach to the Calcaneus

Applied Surgical Anatomy of the Approaches to the Ankle

Applied Surgical Anatomy of the Approaches to the Hindpart of the Foot

Midfoot

Dorsal Approaches to the Middle Part of the Foot

 

Forefoot

Dorsal Approaches to the Metatarsophalangeal Joint of the Great Toe

Dorsomedial Approaches to the Metatarsophalangeal Joint of the Great Toe

Dorsolateral Approach for Bunion Surgery

Dorsal Approach to the Metatarsophalangeal Joints of the Second, Third, Fourth, and Fifth Toes

Dorsal Approach for Morton Neuroma

 

Applied Surgical Anatomy of the Foot

 

Approaches to the structures of the ankle and foot usually are straightforward; the bones and joints that are explored commonly are superficial, if not subcutaneous. Apart from technical problems associated with the surgery itself, the most common complication in foot and ankle surgery is poor wound healing. For this reason, it is important to evaluate both the circulation and the sensation of the foot. Ischemic or neuropathic feet heal poorly and are a frequent contraindication to elective surgery. In patients with diabetes, ischemia and neuropathy may coexist; all feet of such patients must be evaluated carefully before any foot surgery is undertaken. Smoking is also a relative contraindication to surgery, especially in cases of open reduction and internal fixation of fractures of the calcaneus.

Wound healing also is affected by the thickness of the skin flaps that are cut; it is important to cut these flaps as thickly as possible and to avoid forceful retraction. Longer incisions require less forceful retraction to achieve identical exposure. As a result, they often are safer than are short incisions. (Remember that skin incisions heal from side to side and not from end to end.)

This chapter is divided into three sections. The first describes approaches to the ankle and the hindpart of the foot, because most provide access to both areas. The anterior approach to the ankle is used for arthrodesis; it offers excellent exposure of the anterior compartment of the

ankle joint. The approach to the medial malleolus is a commonly used incision, providing access to the distal tibia in cases of fracture. A more extensive approach to the medial side of the ankle joint also exposes the distal tibia, but involves an osteotomy. The posteromedial approach to the ankle exposes the soft tissues of the area. It is used frequently for soft tissue operations, including the surgical correction of clubfoot. The posterolateral approach to the ankle joint provides limited access to the back of the joint and the posterior facet of the subtalar joint. The lateral approach to the ankle and hindpart of the foot exposes the ankle and the joints of the hindfoot. The lateral approach to the hindpart of the foot and the posterolateral approach to the talocalcaneal joint are used for surgery on the joints of the posterior part of the foot. The lateral approach to the calcaneus exposes the lateral aspect of the calcaneus, the calcaneocuboid, and subtalar joints. It is mainly used for open reduction and internal fixation of the os calcis.

The second section of this chapter describes approaches to the midportion of the foot, the tarsometatarsal and midtarsal joints and those muscles that attach to them. Surgery in this area is relatively uncommon in general orthopedic practice; it usually is associated with specific operative procedures designed for single pathologic states. Because these structures are very superficial, the approaches are dealt with mainly pictorially.

The final section contains three of the most common approaches in surgery of the forepart of the foot. The dorsal and dorsomedial approaches to the metatarsophalangeal joint of the great toe are used in surgery for hallux valgus; the dorsal approach to the metatarsophalangeal joints of the second, third, fourth, and fifth toes provides safe access to these joints; and the approach to the dorsal web spaces can be used for the treatment of several conditions, including Morton neuroma. The latter approach also can be used to reach the metatarsophalangeal joint. The dorsolateral approach to the metatarsophalangeal joint of the great toe is nearly always used in conjunction with other approaches in the treatment of hallux valgus.

The applied anatomy of the foot appears in two sections after this group of approaches. The first section deals with the applied anatomy of the approaches, that is, the applied anatomy of the dorsum of the foot. The second section, an account of the anatomy of the sole of the foot, should provide an understanding of those structures that may be damaged in severe foot trauma or infection.

Anterior Approach to the Ankle ‌‌

The anterior approach provides excellent exposure of the ankle joint for arthrodesis.1 The decision to use this approach rather than the lateral transfibular approach, the medial transmalleolar approach, or the posterior approach depends on the condition of the skin and the surgical technique to be used. Its other uses include the following:

1. Drainage of infections in the ankle joint

2. Removal of loose bodies

3. Open reduction and internal fixation of comminuted distal tibial fractures (pilon fractures)

 

Position of the Patient

 

Place the patient supine on the operating table. Partially exsanguinate the foot either by elevating it for 3 to 5 minutes or by applying a soft rubber bandage loosely to the foot and binding it firmly to the calf. Then, inflate a thigh tourniquet. Partial exsanguination allows the neurovascular bundle to be identified, because the venous structures will appear blue. Some continuous vascular oozing must be expected, however (Fig. 12-1).

 

 

 

Figure 12-1 Position for the anterior approach to the ankle.

 

Landmarks and Incision

Landmarks

The medial malleolus is the bulbous, subcutaneous, distal end of the medial surface of the tibia. The lateral malleolus is the subcutaneous distal end of the fibula.

Incision

Make a 15-cm longitudinal incision over the anterior aspect of the ankle joint. Begin about 10 cm proximal to the joint, and extend the incision so that it crosses the joint about midway between the malleoli, ending on the dorsum of the foot. Take great care to cut only the skin; the anterior neurovascular bundle and branches of the superficial peroneal nerve cross the ankle joint very close to the line of the skin incision (Fig. 12-2A). Alternatively, make a 15-cm longitudinal incision with its center overlying the anterior aspect of the medial malleolus (see Fig. 12-2).

 

Internervous Plane

 

Although the approach uses no true internervous plane, the extensor hallucis longus and extensor digitorum longus muscles define a clear intermuscular plane. Both muscles are supplied by the deep peroneal nerve, but the plane may be used because both receive their nerve supplies well proximal to the level of the dissection. The plane must be used with great caution, however, because it contains the neurovascular bundle distal to the ankle (see Figs. 12-58 and 12-59).

 

Superficial Surgical Dissection

 

Incise the deep fascia of the leg in line with the skin incision, cutting through the extensor retinaculum (see Fig. 12-2B). Find the plane between the extensor hallucis longus and extensor digitorum longus muscles a few centimeters above the ankle joint, and identify the neurovascular bundle (the anterior tibial artery and the deep peroneal nerve) just medial to the tendon of the extensor hallucis longus (see Fig. 12-2C). Trace the bundle distally until it crosses the front of the ankle joint behind the tendon of the extensor hallucis longus. Retract the tendon of the extensor hallucis longus medially, together with the neurovascular bundle. Retract the tendon of the extensor digitorum longus laterally. The tendons become mobile after the

retinaculum has been cut, but the neurovascular bundle adheres to the underlying tissues and requires mobilization (Fig. 12-3A).

Alternatively, in pilon fractures, incise the deep fascia to the medial side of the tibialis anterior tendon (Fig. 12-4), and expose the underlying surface of the tibia together with the anteromedial ankle joint capsule.

 

Deep Surgical Dissection

 

For arthrodesis surgery, incise the remaining soft tissues longitudinally to expose the anterior surface of the distal tibia. Continue incising down to the ankle joint, then cut through its anterior capsule. Expose the full width of the ankle joint by detaching the anterior ankle capsule from the tibia or the talus by sharp dissection (see Fig. 12-3). Some periosteal stripping of the distal tibia may be required. Although the periosteal layer usually is thick and easy to define, the plane may be obliterated in cases of infection; the periosteum then must be detached piecemeal by sharp dissection.

 

 

 

Figure 12-2 A: Make a longitudinal incision over the anterior aspect of the ankle joint. B: Identify and protect the superficial peroneal nerve. Incise the extensor retinaculum in line with the skin incision. C: Identify the plane between the extensor hallucis longus and the extensor digitorum longus, and note the neurovascular bundle between them.

 

 

Figure 12-3 A: Retract the tendon of the extensor hallucis longus medially with the neurovascular bundle. Retract the tendon of the extensor digitorum longus laterally. Incise the joint capsule longitudinally. B: Retract the joint capsule to expose the ankle joint.

 

If the approach is used in fracture surgery, take great care to preserve as much soft tissue attachments to bone as possible. Meticulous preoperative planning will allow smaller, precise incisions with consequent reduction in soft tissue damage.

 

 

Dang

 

 

Nerves

Cutaneous branches of the superficial peroneal nerve run close to the line of the skin incision just under the skin. Take care not to cut them during incision of the skin (see Fig. 12-2A).

The deep peroneal nerve and anterior tibial artery (the anterior neurovascular bundle) must be identified and preserved during superficial surgical dissection. They are in greatest danger during the skin incision, because they are superficial and run close to the incision itself (see Figs. 12-58 and 12-59). Above the ankle joint, the neurovascular bundle lies

between the tendons of the extensor hallucis longus and tibialis anterior muscles at the joint; the tendon of the extensor hallucis longus crosses the bundle. The plane between the tibialis anterior and the extensor hallucis longus can be used as long as the neurovascular bundle is identified and mobilized so as to preserve it (see Fig. 12-59).

 

How to Enlarge the Approach

Extensile Measures

Although this approach does not descend through an internervous plane, on occasion it can be extended proximally to expose the structures in the anterior compartment. To expose the proximal tibia, use the plane between the tibia and the tibialis anterior muscle (see Fig. 12-4). Distal extension to the dorsum of the foot is possible, but rarely, if ever, required (see Fig. 12-59).

 

 

 

Figure 12-4 A: Alternately, incise the extensor retinaculum on the medial side of the tibialis anterior tendon. B: Retract the tibialis anterior laterally to expose the anterior surface of the ankle joint.

Anterior and Posterior Approaches to the Medial Malleolus‌

 

 

The anterior and posterior approaches are used mainly for open reduction and internal fixation of fractures of the medial malleolus.2 The approaches provide excellent visualization of the malleolus.

 

Position of the Patient

 

Place the patient supine on the operating table. The natural position of the leg (slight external rotation) exposes the medial malleolus well. Exsanguinate the limb by elevating it for 3 to 5 minutes, then inflate a tourniquet. Standing or sitting at the foot of the table makes it easier to angle drills correctly (Fig. 12-5).

 

Incisions

 

Two skin incisions are available.

1. The anterior incision offers an excellent view of medial malleolar fractures. It also permits inspection of the anteromedial ankle joint and the anteromedial part of the dome of the talus.

   Make a 10-cm longitudinal curved incision on the medial aspect of the ankle, with its midpoint just anterior to the tip of the medial malleolus. Begin proximally, 5 cm above the malleolus and over the middle of the subcutaneous surface of the tibia. Then, cross the anterior third of the medial malleolus, and curve the incision forward to end some 5 cm anterior and distal to the malleolus. The incision should not cross the most prominent portion of the malleolus (Fig. 12-6).

2. The posterior incision allows reduction and fixation of medial malleolar fractures and visualization of the posterior margin of the tibia.

Make a 10-cm incision on the medial side of the ankle. Begin 5 cm above the ankle on the posterior border of the tibia, and curve the incision downward, following the posterior border of the medial malleolus. Curve the incision forward below the medial malleolus to end 5 cm distal to the malleolus (see Fig. 12-10).

 

 

Figure 12-5 Position for the approach to the medial malleolus. The leg falls naturally into a few degrees of external rotation to expose the malleolus.

 

 

Figure 12-6 Keep the incision just anterior to the tip of the medial malleolus.

 

Internervous Plane

 

No true internervous plane exists in this approach, but the approach is safe because the incision cuts down onto subcutaneous bone.

 

Superficial Surgical Dissection

Anterior Incision

Gently mobilize the skin flaps, taking care to identify and preserve the long saphenous vein, which lies just anterior to the medial malleolus. Accurately locating the skin incision will make it unnecessary to mobilize the skin flaps extensively. Next to the vein runs the saphenous nerve, two branches of which are bound to the vein. Take care not to damage the

nerve; damage leads to the formation of a neuroma. Because the nerve is small and not easily identified, the best way to preserve it is to preserve the long saphenous vein, a structure that on its own is of little functional significance (Fig. 12-7). Posterior incision mobilize the skin flaps. The saphenous nerve is not in danger (see Fig. 12-11).

 

Deep Surgical Dissection

 

In cases of fracture, the periosteum already is breached. Protect as many soft tissue attachments to the bone fragment as possible to preserve its blood supply.

Anterior Incision

Incise the remaining coverings of the medial malleolus longitudinally to expose the fracture site. Make a small incision in the anterior capsule of the ankle joint so that the joint surfaces can be seen after the fracture is reduced (Fig. 12-8). This is especially important in vertical fractures of the medial malleolus where impaction at the joint surface frequently occurs. The superficial fibers of the deltoid ligament run anteriorly and distally downward from the medial malleolus; split them so that wires or screws used in internal fixation can be anchored solidly on bone, with the heads of the screws covered by soft tissue (Fig. 12-9; see Fig. 12-56).

Posterior Incision

Incise the retinaculum behind the medial malleolus longitudinally so that it can be repaired (Figs. 12-10 and 12-11). Take care not to cut the tendon of the tibialis posterior muscle, which runs immediately behind the medial malleolus; the incision into the retinaculum permits anterior retraction of the tibialis posterior tendon. Continue the dissection around the back of the malleolus, retracting the other structures that pass behind the medial malleolus posteriorly to reach the posterior margin (or posterior malleolus) of the tibia. The exposure allows reduction in some fractures of that part of the bone.

 

 

Figure 12-7 Widen the skin flaps. Identify the long saphenous vein and the accompanying saphenous nerve.

 

 

Figure 12-8 Make a small incision in the anterior capsule of the ankle joint to see the articulating surface.

 

 

Figure 12-9 Split fibers of the deltoid ligament to allow for internal fixation of the fractured malleolus.

 

 

Figure 12-10 The posterior incision for the approach to the medial malleolus follows the posterior border of the medial malleolus.

 

 

Figure 12-11 Retract the skin flaps and begin to incise the retinaculum behind the medial malleolus.

 

Note that, although this approach will allow visualization of most fractures using appropriate reduction forceps, the angle of the approach is such that the displaced fragments cannot be fixed internally from this approach. Separate anterior approaches are required to lag any posterior fragments back. It always is advisable to obtain an intraoperative radiograph showing the displaced fragment fixed temporarily with a Kirschner wire (K-wire) before definitive fixation is inserted. Reduction in these fragments is difficult because of limited exposure, and inaccurate reduction may occur. To improve the view of the posterior malleolus, externally rotate the leg still further (Fig. 12-12; see Figs. 12-55 and 12-56).

Dangers of the Anterior Incision

 

 

Nerves

The saphenous nerve, if cut, forms a neuroma and may cause numbness over the medial side of the dorsum of the foot. Preserve the nerve by preserving the long saphenous vein.

Vessels

The long saphenous vein is at risk when the anterior skin flaps are mobilized. Preserve it if possible, so that it can be used as a vascular graft in the future (see Fig. 12-54).

 

 

Dangers of the Posterior Incision

 

 

All the structures that run behind the medial malleolus (the tibialis posterior muscle, the flexor digitorum longus muscle, the posterior tibial artery and vein, the tibial nerve, and the flexor hallucis longus tendon) are in danger if the deep surgical dissection is not carried out close to bone (see Figs. 12-54 to 12-56).

Leave as much soft tissue attached to fractured malleolar fragments as possible; complete stripping renders fragments avascular.

 

How to Enlarge the Approach

Extensile Measures

To enlarge both approaches proximally, continue the incision along the subcutaneous surface of the tibia. Subperiosteal dissection exposes the subcutaneous and lateral surfaces of the tibia along its entire length. The exposure can be extended distally to expose the deltoid ligaments and the talocalcaneonavicular joint.

 

 

Figure 12-12 Anteriorly retract the tibialis posterior. Free up and retract the remaining structures around the back of the malleolus posteriorly to expose the posterior aspect of the medial malleolus.

 

Approach to the Medial Side of the Ankle ‌

The medial approach exposes the medial side of the ankle joint.3 Its uses include the following:

1. Arthrodesis of the ankle

2. Excision or fixation of osteochondral fragments from the medial side of the talus

3. Removal of loose bodies from the ankle joint

 

Position of the Patient

 

Place the patient supine on the operating table. Exsanguinate the limb

either by elevating it for 5 minutes or by applying a soft rubber bandage firmly; then inflate a tourniquet. The natural external rotation of the leg exposes the medial malleolus. The pelvis ordinarily does not have to be tilted to improve the exposure (see Fig. 12-5).

 

Landmark and Incision

Landmark

The medial malleolus is the palpable distal end of the tibia.

Incision

Make a 10-cm longitudinal incision on the medial aspect of the ankle joint, centering it on the tip of the medial malleolus. Begin the incision over the medial surface of the tibia. Below the malleolus, curve it forward onto the medial side of the middle part of the foot (Fig. 12-13).

 

Internervous Plane

 

The approach uses no internervous plane. Nevertheless, the surgery is safe because the tibia is subcutaneous and all dissection stays on bone.

 

 

Figure 12-13 Make a 10-cm longitudinal incision on the medial aspect of the ankle joint, with its center over the tip of the medial malleolus. Distally, curve the incision forward onto the medial side of the middle part of the foot.

 

Superficial Surgical Dissection

 

Mobilize the skin flaps, taking care not to damage the long saphenous vein and the saphenous nerve, which run together along the anterior border of the medial malleolus (Fig. 12-14).

 

Deep Surgical Dissection

 

To uncover the point at which the medial malleolus joins the shaft of the tibia, make a small longitudinal incision in the anterior part of the joint capsule.

Divide the flexor retinaculum and identify the tendon of the tibialis posterior muscle, which runs immediately behind the medial malleolus, grooving the bone (see Fig. 12-14). Retract the tendon posteriorly to expose the posterior surface of the malleolus (Fig.12-15A).

Score the bone longitudinally to ensure correct alignment of the malleolus during closure. Then, drill and tap the medial malleolus so that it can be reattached (see Fig. 12-15B).

Using an osteotome or oscillating saw, cut through the medial malleolus obliquely from top to bottom; cut laterally at its junction with the shaft of the tibia, checking the position of the cut through the incision in the anterior joint capsule (see Fig. 12-15).

Retract the medial malleolus (with its attached deltoid ligaments) downward and forcibly evert the foot, bringing the dome of the talus and the articulating surface of the tibia into view (Figs. 12-16 and 12-17). Eversion is limited because of the intact fibula.

 

 

Dang

 

 

The saphenous nerve and the long saphenous vein should be preserved as a unit, largely to prevent damage to the saphenous nerve and subsequent neuroma formation.

The tendon of the tibialis posterior muscle is in particular danger during this approach, because it lies immediately posterior to the medial malleolus. Preserve the tendon by releasing and retracting it while performing osteotomy of the malleolus (see Figs. 12-14 and 12-15A). The tendons of the flexor hallucis longus and flexor digitorum longus muscle, together with the posterior neurovascular bundle, lie more posteriorly and laterally. They are in no danger as long as the osteotomy is performed carefully (see Figs. 12-55 and 12-57).

 

 

 

Figure 12-14 Carefully retract the skin flaps to protect the long saphenous vein and the accompanying saphenous nerve. Incise the flexor retinaculum, and make a small incision into the anterior joint capsule.

 

 

Figure 12-15 A: Retract the tibialis tendon posteriorly. Drill and tap the medial malleolus, and score the potential osteotomy site for future alignment. B: The line of the osteotomy and the score marks for the reattachment of the medial malleolus.

 

 

Figure 12-16 Retract the osteotomized medial malleolus downward.

 

 

Figure 12-17 Forcefully evert the foot to bring the dome of the talus and the anterior surface of the tibia into view.

 

Special Surgical Points

 

In cases of fracture, the interdigitation of the broken ends of bone prevents rotation between the two fragments when a screw is inserted and tightened. No such interdigitation exists in an osteotomy. Therefore, two K-wires should be used in addition to a screw to prevent rotation when the screw is tightened. After the osteotomy has been stabilized with the screw, the two K-wires can be removed. Tension band fixation also may be used. In any case, align the bones correctly by aligning the score marks made on the bone before the osteotomy.

 

How to Enlarge the Approach

 

The approach usually is not enlarged either distally or proximally.

 

Posteromedial Approach to the Ankle ‌

The posteromedial approach to the ankle joint is routinely used for exploring the soft tissues that run around the back of the medial malleolus. This approach is used for the release of soft tissue around the medial malleolus in the treatment of clubfoot.4

The approach can also be used to allow access to the posterior malleolus of the ankle joint, but gives limited exposure of the fracture site and is technically demanding. For this reason, reduction and fixation of posterior malleolar fractures is usually achieved by indirect techniques.

 

Position of the Patient

 

Either of two positions is available for this approach. First, place the patient supine on the operating table. Flex the hip and knee, and place the lateral side of the affected ankle on the anterior surface of the opposite knee. This position will achieve full external rotation of the hip, permitting better exposure of the medial structures of the ankle (Fig. 12-18). Alternatively, place the patient in the lateral position with the affected leg nearest the table. Flex the knee of the opposite limb to get its ankle out of the way.

 

 

 

Figure 12-18 Place the patient supine on the operating table with the knee and the hip flexed to expose the medial structures of the ankle.

Exsanguinate the limb by elevating it for 3 to 5 minutes or applying a soft rubber bandage; then inflate a tourniquet.

 

Landmarks and Incision

Landmarks

The medial malleolus is the bulbous, distal, subcutaneous end of the tibia.

Palpate the Achilles tendon just above the calcaneus.

Incision

Make an 8- to 10-cm longitudinal incision roughly midway between the medial malleolus and the Achilles tendon (Fig. 12-19).

 

Superficial Surgical Dissection

 

Deepen the incision in line with the skin incision to enter the fat that lies between the Achilles tendon and those structures that pass around the back of the medial malleolus. If the Achilles tendon must be lengthened, identify it in the posterior flap of the wound and perform the lengthening now. Identify a fascial plane in the anterior flap that covers the remaining flexor tendons. Incise the fascia longitudinally, well away from the back of the medial malleolus (Figs. 12-20 and 12-21).

 

Deep Surgical Dissection

 

There are three different ways to approach the back of the ankle joint.

First, identify the flexor hallucis longus, the only muscle that still has muscle fibers at this level (see Fig. 12-21).

At its lateral border, develop a plane between it and the peroneal tendons, which lie just lateral to it (Fig. 12-22). Deepen this plane to expose the posterior aspect of the ankle joint by retracting the flexor hallucis longus medially (Fig. 12-23).

Second, identify the flexor hallucis longus and continue the dissection anteriorly toward the back of the medial malleolus. Preserve the neurovascular bundle by mobilizing it gently and retracting it and the flexor hallucis longus laterally to develop a plane between the bundle and the tendon of the flexor digitorum longus. This approach brings one onto the posterior aspect of the ankle joint rather more medially than does the first approach.

 

 

Figure 12-19 Make an 8- to 10-cm longitudinal incision roughly between the medial malleolus and the Achilles tendon.

 

Third, when all the tendons that run around the back of the medial malleolus (the tibialis posterior, flexor digitorum longus, and flexor hallucis longus) must be lengthened, the back of the ankle can be approached directly, because the posterior coverings of the tendons must be divided during the lengthening procedure.

For all three methods, complete the approach by incising the joint capsule either longitudinally or transversely.

Dang

 

 

The posterior tibial artery and the tibial nerve (the posterior neurovascular bundle) are vulnerable during the approach. Take care not to apply forceful retraction to the nerve, as this may lead to a neurapraxia. Note that the tibial nerve is surprisingly large in young children and that the tendon of the flexor digitorum longus muscle is extremely small. Take care to identify positively all structures in the area before dividing any muscle tendons (see Figs. 12-54 and 12-55).

 

How to Enlarge the Approach

Extensile Measures

Extend the incision distally by curving it across the medial border of the ankle, ending over the talonavicular joint. This extension exposes both the talonavicular joint and the master knot of Henry. As is true for all long, curved incisions around the ankle, skin necrosis can result if the skin flaps are not cut thickly or if forcible retraction is applied.

 

 

Figure 12-20 Incise the deep fascia in line with the skin incision.

 

 

Figure 12-21 Retract the Achilles tendon and the retrotendinous fat laterally, exposing the fascia of the deeper flexor compartment. Open the compartment, and identify the muscle fibers of the flexor hallucis longus.

 

 

Figure 12-22 Identify the posterior tibial artery and tibial nerve. Then, incise the fibro-osseous tunnel over the flexor hallucis longus tendon and the other medial tendons so that the structures can be mobilized and retracted medially.

 

 

Figure 12-23 Retract the posterior structures medially, exposing the posterior portion of the ankle joint.

 

Posterolateral Approach to the Ankle ‌

The posterolateral approach is used to treat conditions of the posterior aspect of the distal tibia and ankle joint. It is well suited for open reduction and internal fixation of posterior malleolar fractures. Because the patient is prone, however, it is not the approach of choice if the fibula and medial malleolus have to be fixed at the same time. In such cases, it is better to use either a posteromedial approach or a lateral approach to the fibula, and to approach the posterolateral corner of the tibia through the site of the fractured fibula. Neither of these approaches provides such good

visualization of the bone as does the posterolateral approach to the ankle, but both allow other surgical procedures to be carried out without changing the position of the patient on the table halfway through the operation. Its other uses include the following:

1. Excision of sequestra

2. Removal of benign tumors

3. Arthrodesis of the posterior facet of the subtalar joint

4. Posterior capsulotomy and syndesmotomy of the ankle

5. Elongation of tendons

 

Position of the Patient

 

Place the patient prone on the operating table. As always, when the prone position is being used, longitudinal pads should be placed under the pelvis and chest so that the center portion of the chest and abdomen are free to move with respiration. A sandbag should be placed under the ankle so that it can be extended during the operation. Next, exsanguinate the limb by elevating it for 3 to 5 minutes or applying a soft rubber bandage; then inflate a tourniquet (Fig. 12-24).

 

Landmarks and Incision

Landmarks

The lateral malleolus is the subcutaneous distal end of the fibula. The Achilles tendon is easily palpable as it approaches its insertion into the calcaneus.

Incision

Make a 10-cm longitudinal incision halfway between the posterior border of the lateral malleolus and the lateral border of the Achilles tendon. Begin the incision at the level of the tip of the fibula and extend it proximally (Fig. 12-25).

 

Internervous Plane

 

The internervous plane lies between the peroneus brevis muscle (which is supplied by the superficial peroneal nerve) and the flexor hallucis longus muscle (which is supplied by the tibial nerve; Fig. 12-26).

 

 

Figure 12-24 Position of the patient for the posterolateral approach to the ankle joint.

 

Superficial Surgical Dissection

 

Mobilize the skin flaps. The short saphenous vein and sural nerves run just behind the lateral malleolus; they should be well anterior to the incision. Incise the deep fascia of the leg in line with the skin incision, and identify the two peroneal tendons as they pass down the leg and around the back of the lateral malleolus (Fig. 12-27). The tendon of the peroneus brevis muscle is anterior to that of the peroneus longus muscle at the level of the ankle joint and, therefore, is closer to the lateral malleolus. Note that the peroneus brevis is muscular almost down to the ankle, whereas the peroneus longus is tendinous in the distal third of the leg (see Figs. 12-64 and 12-65).

Incise the peroneal retinaculum to release the tendons, and retract the muscles laterally and anteriorly to expose the flexor hallucis longus muscle (Fig. 12-28). The flexor hallucis longus is the most lateral of the deep

flexor muscles of the calf. It is the only one that is still muscular at this level (see Fig. 12-65).

 

Deep Surgical Dissection

 

To enhance the exposure, make a longitudinal incision through the lateral fibers of the flexor hallucis longus muscle as they arise from the fibula (Fig. 12-29). Retract the flexor hallucis longus medially to reveal the periosteum over the posterior aspect of the tibia (Fig. 12-30). If the distal tibia must be reached, develop an epiperiosteal plane between the periosteum covering the tibia and the overlying soft tissues. To enter the ankle joint, follow the posterior aspect of the tibia down to the posterior ankle joint capsule and incise it transversely.

 

 

 

Figure 12-25 Make a 10-cm longitudinal incision halfway between the posterior

border of the lateral malleolus and the lateral border of the Achilles tendon.

 

 

 

Figure 12-26 The internervous plane lies between the peroneus brevis (which is supplied by the superficial peroneal nerve) and the flexor hallucis longus (which is supplied by the tibial nerve).

 

 

Figure 12-27 Mobilize the skin flaps. Incise the deep fascia of the leg in line with the skin incision. Identify the two peroneal tendons as they pass around the ankle.

 

 

Dang

 

 

The short saphenous vein and the sural nerve run close together. They should be preserved as a unit, largely to prevent the formation of a painful neuroma (see Fig. 12-64).

 

How to Enlarge the Approach

Extensile Measures

To enlarge the approach proximally, extend the skin incision superiorly and identify the plane between the lateral head of the gastrocnemius muscle and the peroneus muscles. Develop this plane down to the soleus

muscle; retract it medially with the gastrocnemius. Next, reflect the flexor hallucis longus muscle medially, detaching it from its origin on the fibula. Continue the dissection medially across the interosseous membrane to the posterior aspect of the tibia.

 

 

 

Figure 12-28 Incise the peroneal retinaculum to release the tendons. Retract them laterally and anteriorly. Incise the fascia over the flexor hallucis longus to expose its muscle fibers.

 

 

Figure 12-29 Make a longitudinal incision through the lateral fibers of the flexor hallucis longus as they arise from the fibula.

 

 

Figure 12-30 Retract the flexor hallucis longus medially to reveal the periosteum covering the posterior aspect of the tibia.

 

Lateral Approach to the Lateral Malleolus‌

The approach to the lateral malleolus is used primarily for open reduction and internal fixation of lateral malleolar fractures. It also offers access to the posterolateral aspect of the tibia.

 

Position of the Patient

 

Place the patient supine on the operating table with a sandbag under the buttock of the affected limb. The sandbag causes the limb to rotate medially, bringing the lateral malleolus forward and making it easier to

reach (Fig. 12-31). Tilt the table away from you to further increase the internal rotation of the limb. Operating with the patient on his or her side also provides excellent access to the distal fibula, but the medial malleolus cannot be reached unless the patient’s position is changed, something that is necessary in the fixation of bimalleolar fractures (Fig. 12-32). Exsanguinate the limb by elevating it for 3 to 5 minutes, then inflate a tourniquet.

 

Landmarks and Incision

Landmarks

Palpate the subcutaneous surface of the fibula and the lateral malleolus, which lies at its distal end. The short saphenous vein can be seen running along the posterior border of the lateral malleolus before the limb is exsanguinated.

Incision

Make a 10- to 15-cm longitudinal incision along the posterior margin of the fibula all the way to its distal end and continuing for a further 2 cm (Fig. 12-33A). In fracture surgery, center the incision at the level of the fracture.

 

Internervous Plane

 

There is no internervous plane, because the dissection is being performed down to a subcutaneous bone. For higher fractures of the fibula, the internervous plane lies between the peroneus tertius muscle (which is supplied by the deep peroneal nerve) and the peroneus brevis muscle (which is supplied by the superficial peroneal nerve).

 

Superficial Surgical Dissection

 

Elevate the skin flaps, taking care not to damage the short saphenous vein, which lies posterior to the lateral malleolus. The sural nerve, which runs with the short saphenous vein, also should be preserved.

 

Deep Surgical Dissection

 

Incise the periosteum of the subcutaneous surface of the fibula longitudinally, and strip off just enough of it at the fracture site to expose the fracture adequately. Take care to keep all dissection strictly

subperiosteal, because the terminal branches of the peroneal artery, which lie close to the lateral malleolus, may be damaged. Only strip off as much periosteum as is necessary for accurate reduction; periosteal stripping markedly reduces the blood supply of the bone in cases of fracture (Fig. 12-33B,C; see Fig. 12-64).

 

 

 

Figure 12-31 Position of the patient for exposure of the lateral malleolus.

 

 

 

Figure 12-32 An alternate position for exposure of the lateral malleolus. Place the patient prone or on his or her side, with a sandbag under the pelvis of the affected side.

 

 

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. Preserve it if possible (see Fig. 12-61).

Vessels

The terminal branches of the peroneal artery lie immediately deep to the medial surface of the distal fibula. They can be damaged if dissection is extensive. The damage may not be noticed during surgery because of the tourniquet, but a hematoma may form after the tourniquet is taken off. That is why it is best to deflate the tourniquet before closure to ensure hemostasis; then, the wound can be drained with a suction drain (see Fig. 12-64).

 

How to Enlarge the Approach

Extensile Measures

 

Proximal Extension. Extend the incision along the posterior border of the fibula, incising the deep fascia in line with the skin incision. Develop a new plane between the peroneal muscles (which are supplied by the superficial peroneal nerve) and the flexor muscles (which are supplied by the tibial nerve). The upper third of the fibula can be exposed if the common peroneal nerve can be identified near the knee and traced down toward the ankle. (For details of this approach, see Approach to the Fibula in Chapter 11, page 617.)

 

Distal Extension. To extend the approach distally, curve the incision down the lateral side of the foot. Identify the peroneal tendons and incise the peroneal retinacula. Detach the fat pad in the sinus tarsi and the origin of the extensor digitorum brevis muscle to expose the calcaneocuboid joint on the lateral side of the tarsus (see Figs. 12-61 and 12-62).

 

 

Figure 12-33 A: Make a 10- to 15-cm incision along the posterior margin of the fibula all the way to its distal end. From there, curve the incision forward, below the tip of the lateral malleolus. B: Incise the periosteum on the subcutaneous surface of the fibula longitudinally. C: Expose the distal fibula subperiosteally.

Anterolateral Approach to the Ankle and Hindpart of the Foot‌

 

 

The full extent of the anterolateral approach to the ankle and hindpart of the foot allows exposure not only of the ankle joint but also of the talonavicular, calcaneocuboid, and talocalcaneal joints. The approach is used commonly for ankle fusions, but also can be used for triple arthrodesis and even pantalar arthrodesis. In addition, it is possible to excise the entire talus through this approach, or to reduce it in cases of talar dislocation.

 

Position of the Patient

 

Place the patient supine on the operating table; place a large sandbag underneath the affected buttock to rotate the leg internally and bring the lateral malleolus forward. 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

Palpate the lateral malleolus at the distal subcutaneous end of the fibula.

Palpate the base of the fifth metatarsal, a prominent bony mass on the lateral aspect of the foot.

Incision

Make a 15-cm slightly curved incision on the anterolateral aspect of the ankle. Begin some 5 cm proximal to the ankle joint, 2 cm anterior to the anterior border of the fibula. Curve the incision down, crossing the ankle joint 2 cm medial to the tip of the lateral malleolus, and continue onto the foot, ending some 2 cm medial to the fifth metatarsal base, over the base of the fourth metatarsal (Fig. 12-34).

 

Internervous Plane

 

The internervous plane lies between the peroneal muscles (which are supplied by the superficial peroneal nerve) and the extensor muscles (which are supplied by the deep peroneal nerve; see Figs. 12-58 and 12-

61).

 

Superficial Surgical Dissection

 

Incise the fascia in line with the skin incision, cutting through the superior and inferior extensor retinacula. Do not develop skin flaps. Take care to identify and preserve any dorsal cutaneous branches of the superficial peroneal nerve that may cross the field of dissection (Fig. 12-35). Identify the peroneus tertius and extensor digitorum longus muscles, and, in the upper half of the wound, incise down to bone just lateral to these muscles (Fig. 12-36).

 

Deep Surgical Dissection

 

Retract the extensor musculature medially to expose the anterior aspect of the distal tibia and the anterior ankle joint capsule. Distally, identify the extensor digitorum brevis muscle at its origin from the calcaneus (Fig. 12-37) and detach it by sharp dissection. During dissection, branches of the lateral tarsal artery will be cut; cauterize (diathermy) these to prevent the formation of a postoperative hematoma. Reflect the detached extensor digitorum brevis muscle distally and medially, lifting the muscle fascia and the subcutaneous fat and skin as one flap. Identify the dorsal capsules of the calcaneocuboid and talonavicular joints, which lie next to each other across the foot, forming the clinical midtarsal joint (see Fig. 12-60). Next, identify the fat in the sinus tarsi and clear it away to expose the talocalcaneal joint, either by mobilizing the fat pad and turning it downward or by excising it. Preserving the fat pad prevents the development of a cosmetically ugly dimple postoperatively. Preserving the pad also helps the wound to heal (Fig. 12-38).

Finally, incise any or all the capsules that have been exposed. To open the joints, forcefully flex and invert the foot in a plantar direction (see Fig. 12-38).

 

 

Dang

 

 

The deep peroneal nerve and anterior tibial artery cross the front of the ankle joint. They are vulnerable if dissection is not carried out as close to the bone as possible (see Fig. 12-58).

How to Enlarge the Approach

Extensile Measures

The approach can be extended proximally to explore structures in the anterior compartment of the leg. Continue the incision over the compartment, and incise the thick deep fascia in line with the skin incision. The approach also can be extended distally to expose the tarsometatarsal joint on the lateral half of the foot. Continue the incision over the fourth metatarsal, and expose the subcutaneous tarsometatarsal

joints.

 

 

 

Figure 12-34 Incision for the anterolateral approach to the ankle. Make a 15-cm

slightly curved incision on the anterolateral aspect of the ankle. Begin approximately 5 cm proximal to the ankle joint and 2 cm anterior to the anterior border of the fibula. Curve the incision downward to cross the ankle joint 2 cm medial to the tip of the lateral malleolus, and continue onto the foot, ending about 2 cm medial to the fifth metatarsal.

 

 

 

Figure 12-35 Incise the deep fascia and the superior and inferior retinacula in line with the incision. Take care to preserve the superficial peroneal nerve.

 

 

Figure 12-36 Identify the peroneus tertius and the extensor digitorum longus muscles, and incise down to bone lateral to them in the upper half of the wound.

 

 

Figure 12-37 Retract the extensor musculature medially to expose the anterior aspect of the distal tibia and ankle joint. Identify the origin of the extensor digitorum brevis.

 

 

 

Figure 12-38 The extensor digitorum brevis has been detached from its origin and reflected distally. The fat pad covering the sinus tarsi has been detached and reflected downward. Incise the joint capsules that have been exposed.

 

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.

 

 

Figure 12-44 Incise the joint capsules of the respective joints.

 

 

Figure 12-45 Reflect the peroneal tendons anteriorly. Incise the joint capsule of 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.

 

 

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.

 

 

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.

 

 

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.

 

 

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.

 

 

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:

1. Open reduction and internal fixation of displaced calcaneal fractures

2. 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.

 

 

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.

 

 

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

 

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 (Fig. 12-52).

 

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).

 

 

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.

 

Applied Surgical Anatomy of the‌

 

Approaches to the Ankle

 

Overview

 

The key structures that cross the ankle joint fall into specific groups.

 

Tendons

 

Three sets of tendons cross the ankle joint in addition to the Achilles and plantaris tendons, which lie posteriorly in the midline.

1. The flexor tendons—the tibialis posterior, flexor digitorum longus, and flexor hallucis longus (which are supplied by the tibial nerve)—pass behind the medial malleolus.

2. The extensor tendons—the tibialis anterior, extensor digitorum longus, extensor hallucis longus, and peroneus tertius (which are supplied by the deep peroneal nerve)—pass in front of the ankle joint.

3. The evertor tendons—the peroneus longus and peroneus brevis (which are supplied by the superficial peroneal nerve)—pass behind the lateral malleolus.

The tendons are all prevented from bowstringing around the ankle by thickened areas in the deep fascia of the leg, called retinacula.

The different nerve supplies of the groups offer three potential internervous planes through which the ankle can be approached: Medially, between flexors (tibialis posterior) and extensors (tibialis anterior); posterolaterally, between flexors (flexor hallucis longus) and evertors (peroneus brevis); and laterally, between extensors (peroneus tertius) and evertors (peroneus brevis).

 

Neurovascular Bundles

 

Two major neurovascular bundles cross the ankle joint and supply the foot. They present the major surgical concerns for all approaches around the ankle.

1. The anterior neurovascular bundle crosses the front of the ankle roughly halfway between the malleoli. It lies between the tibialis anterior and extensor hallucis longus muscles proximal to the joint (see Fig. 12-59) and between the tendons of the extensor hallucis longus and extensor digitorum longus muscles distal to the joint. The tendon of the

   extensor hallucis longus crosses the bundle in a lateral to medial direction at the level of the ankle joint (see Fig. 12-58).

   The anterior tibial artery, which crosses the front of the ankle joint before becoming the dorsalis pedis artery, is palpable on the dorsum of the foot. It also communicates with the medial plantar artery through the first metatarsal space. Fractures through the base of the metatarsal bones and dislocations at the tarsometatarsal joint (Lisfranc fracture/dislocation∗) can damage both elements of this anastomosis and cause ischemia to the medial side of the distal portion of the foot.

   The deep peroneal nerve accompanies the anterior tibial artery. It supplies two small muscles on the dorsum of the foot: The extensor digitorum brevis and the extensor hallucis brevis. It also supplies a sensory branch to the first web space. Anesthesia in this web space is one of the first clinical signs of anterior compartment compression.

   Ischemia of the deep peroneal nerve occurs before ischemic muscle damage (see Figs. 12-58 and 12-59).

2. The posterior neurovascular bundle runs behind the medial malleolus, between the tendons of the flexor digitorum longus and flexor hallucis longus muscles (Figs. 12-54 and 12-55).

The posterior tibial artery passes behind the flexor digitorum longus before entering the sole of the foot, where it divides into medial and lateral plantar arteries (see Fig. 12-55).

The tibial nerve passes behind the medial malleolus with the posterior tibial artery. It gives off a calcaneal branch to the skin of the heel. After entering the sole of the foot, it divides into the medial and lateral plantar nerves, which supply motor power to the small muscles of the foot and sensation to the sole (see Fig. 12-55).

 

 

Figure 12-54 The superficial structures of the medial aspect of the foot and ankle. Fibers of the flexor retinaculum cross the neurovascular bundle, binding it to the medial side of the foot.

 

Superficial Sensory Nerves

 

Three major sensory nerves cross the ankle joint superficially, all supplying the dorsum of the foot. Knowledge of their course is vital in planning skin incisions. The sensory supply to the sole and heel comes from the lateral and medial plantar nerves, which are branches of the tibial nerve that lies deep at the level of the ankle.

1. The saphenous nerve is the terminal branch of the femoral nerve. It runs with the long saphenous vein in front of the medial malleolus, where it usually divides into two branches that lie on either side of the vein and bind closely to it. It supplies the medial, non–weight-bearing side of the middle part and the hindpart of the foot (see Fig. 12-54).

2. The superficial peroneal nerve is a terminal branch of the common peroneal nerve. It crosses the ankle joint roughly along the anterior midline, where it usually divides into several branches. It supplies non–weight-bearing skin on the dorsum of the foot. The nerve is quite superficial at the level of the ankle joint; great care must be taken with

   skin incision in its area (Fig. 12-58; see Fig. 12-82).

3. The sural nerve, a terminal branch of the tibial nerve, runs with the short saphenous vein just behind the lateral malleolus. Similar to the saphenous nerve, the sural nerve binds very closely to its vein; preserving the vein is the key to preserving the nerve during surgery. The sural nerve supplies an area of non–weight-bearing skin on the lateral side of the foot (see Fig. 12-61).

 

Landmarks

Bony Structures of the Ankle

The dome of the talus and the inferior articular surface of the tibia form the articulation that bears weight in the ankle. The joint itself is stabilized by the medial and lateral malleoli, the bony landmarks of the area. The medial malleolus is both shorter and more anterior. It remains in contact with the medial side of the talus throughout the range of motion (see Fig. 12-57).

The configuration of the malleoli causes the ankle mortise to point 15 degrees laterally. During dorsiflexion, the widest portion of the talus (the anterior portion) is the ankle mortise, forcing the mortise itself to widen. The mortise narrows to accommodate the narrower part of the talus during plantar flexion. Hence, if an ankle must be immobilized, it must be put in the functional position, that is, dorsiflexion (Fig. 12-63; see Figs. 12-57, 12-60, and 12-66). Note also that, if a screw is inserted between the fibula and the tibia (as in the reconstruction of a diastasis), then that screw should be inserted with the ankle placed in maximal dorsiflexion.

 

 

Figure 12-55 The extensor retinaculum and part of the flexor retinaculum have been removed to reveal the deeper tendons and the neurovascular bundle. The abductor hallucis has been detached from its origin to reveal the knot of Henry and the medial and lateral plantar arteries and nerves.

 

Medial Approaches to the Ankle

 

Two groups of flexors lie on the medial side of the ankle:

1. Three plantar flexors of the ankle and foot insert into the plantar surface of the foot and are supplied by the tibial nerve. Their positions behind the medial malleolus are remembered best in the form of the mnemonic “Tom, Dick, and Harry.” The tibialis posterior is closest to the medial malleolus; the flexor digitorum longus is behind it; and the flexor hallucis longus is the most posterior and lateral of the three. A second mnemonic, “Timothy Doth Vex Nervous Housemaids,” is older; it points out that the posterior tibial vessels and tibial nerve lie between the flexor digitorum longus and flexor hallucis longus muscles (see Figs.

   12-54 and 12-55).

2. The three muscles that insert into the posterosuperior part of the os calcis (the gastrocnemius, soleus, and plantaris) do so via their common

Achilles tendon. Supplied by the tibial nerve, they are the most powerful plantar flexors of the ankle. Since they insert more to the medial side of the posterior surface of the calcaneus than to the lateral side, they also invert the heel.

The Achilles tendon inserts into the middle third of the posterior surface of the calcaneus. The collagen fibers that comprise the tendon rotate about 90 degrees around its longitudinal axis, between its origin and its insertion onto bone. Viewed from behind, the rotation is in a medial to lateral direction. Thus, fibers that begin on the medial side of the tendon lie posteriorly, and those that begin on the lateral side lie anteriorly at the level of the insertion. This anatomic fact makes it possible to lengthen the Achilles tendon by dividing its anterior two-thirds near the insertion and its medial two-thirds 5 cm more proximally. Dorsiflexion of the foot lengthens the tendon, and no suture is required. The operation can be done either as an open or as a subcutaneous procedure.5 This arrangement of the fibers can be remembered by thinking of this tendon lengthening as the “DAMP operation,” which stands for distal anterior medial proximal.

A fat pad lies between the Achilles tendon and the bone, with a bursa that may become inflamed. A second bursa exists between the insertion of the tendon into the os calcis and the skin (see Fig. 12-54).

The flexor retinaculum is a thickening of the fascia that stretches from the medial malleolus to the back of the calcaneus. It covers the three flexor tendons that pass around the back of the tibial malleolus, as well as the neurovascular bundle.

 

 

Figure 12-56 The flexor and extensor tendons have been resected to expose the deltoid ligament of the ankle joint.

 

 

 

Figure 12-57 Osteology of the medial side of the foot and ankle.

 

 

Figure 12-58 The anatomy of the superficial structures of the anterior portion of the ankle and the dorsum of the foot. At the level of the ankle joint, the neurovascular bundle lies immediately lateral to the extensor hallucis longus tendon.

 

The tibial nerve may be trapped by this retinaculum, producing pain and paresthesia in the distribution of the medial and lateral plantar nerves and their calcaneal branches. The syndrome is known as the tarsal tunnel syndrome (see Fig. 12-54).

Anterior Approach to the Ankle

Extensor Muscles

Four muscles cross the anterior aspect of the ankle joint. All are extensors of the ankle and are supplied by the deep peroneal nerve. The muscles, from medial to lateral, are the tibialis anterior, extensor hallucis longus, extensor digitorum longus, and peroneus tertius. The neurovascular bundle crosses the front of the ankle virtually under the tendon of the extensor hallucis longus (see Fig. 12-58).

Extensor Retinacula

The superior extensor retinaculum is a thickening of the deep fascia above the ankle. It runs between the tibia and the fibula, and is split by the tendon of the tibialis anterior muscle, which lies in a synovial sheath just above the ankle (see Fig. 12-58).

 

 

Figure 12-59 The extensor tendons have been resected to reveal the ligaments of the anterior portion of the ankle joint and the joints of the middle part of the foot.

 

The inferior extensor retinaculum, on the dorsum of the foot, is attached to the lateral side of the upper surface of the os calcis. The retinaculum is split medially; the upper part attaches to the medial malleolus, whereas the lower part travels across the foot, where it sometimes joins the plantar aponeurosis in the sole. The two retinacula prevent the anterior tendons from bowstringing; they should be repaired after any approach that cuts them (see Fig. 12-58).

 

Lateral Approaches to the Ankle

The tendons of the peroneal muscles pass behind the lateral malleolus to reach the foot. Both evert the foot and are supplied by the superficial peroneal nerve (see Fig. 12-61).

The peroneus brevis tendon, which lies immediately behind the lateral malleolus. The peroneus brevis is recognizable both by its position immediately behind the lateral malleolus and by its muscularity almost down to the level of the ankle joint.

The superior peroneal retinaculum is a thickening of the deep fascia extending from the tip of the lateral malleolus to the calcaneus (see Fig. 12-61).

The inferior peroneal retinaculum runs from the peroneal tubercle to the lateral side of the calcaneus (see Fig. 12-61).

The peroneal tendons are enclosed in a synovial sheath as they pass around the back of the lateral malleolus. The sheath encloses both tendons down to the peroneal tubercle. At this point, each tendon gains its own separate sheath. This also is the site of peroneal tendinitis, which commonly occurs in joggers.

 

 

 

Figure 12-60 Osteology of the anterior part of the ankle joint and middle part of the foot.

 

 

Figure 12-61 The superficial anatomy of the lateral and dorsolateral aspects of the foot and ankle. The peroneal tendons are held in place by their superior and inferior retinacula.

 

Figure 12-62 The peroneal and extensor tendons have been resected to reveal the ligaments of the lateral and anterolateral ankle joints. Note the peroneal tubercle and the resected portion of the inferior peroneal retinaculum, which forms separate fibro-osseous tunnels for the peroneal tendons. The calcaneofibular ligament is visible deep to the superior peroneal retinaculum.

 

 

 

Figure 12-63 Osteology of the lateral side of the foot and ankle.

 

Applied Surgical Anatomy of the Approaches to the Hindpart of the Foot‌

 

 

Surgery performed on the hindpart of the foot is confined almost exclusively to three joints: The posterior part of the subtalar joint, the talocalcaneonavicular joint, and the calcaneocuboid joint. The anatomy of the approaches is the anatomy of the joints themselves, because they all are superficial structures (see Figs. 12-63 and 12-66).

The key to the anatomy is the tarsal canal, which runs obliquely across the foot, between the talus and the calcaneus. The canal is formed by two grooves, one on the inferior surface of the talus and the other on the superior surface of the calcaneus. The canal separates the talocalcaneonavicular joint from the talocalcaneal joint and acts as a landmark for surgical access to the two joints. At its lateral end, the canal widens considerably into the sinus tarsi.

The sinus tarsi contains a tough ligament, the ligamentum cervicis tali, and a large fat pad; the ligament must be divided and the fat pad mobilized for access to the sinus and joints. The extensor digitorum brevis muscle originates from the top of the anterior wall of the sinus. It must be detached for access to the calcaneocuboid joint.

Behind the tarsal canal lies the posterior part of the subtalar joint, which consists of a convex superior facet of the talus and a concave facet of the talus. The joint line is oblique when viewed from the lateral (operative) side. To see it better, the peroneal tendons that overlie it partially must be mobilized and retracted anteriorly.

 

 

Figure 12-64 Superficial anatomy of the posterolateral aspect of the foot and ankle. Note that the muscle fibers of the peroneus brevis run all the way to the ankle joint and lie immediately posterior to the lateral malleolus.

 

 

Figure 12-65 The Achilles tendon and the peroneus muscles have been resected to reveal the posterolateral aspect of the ankle joint and the deep flexor tendons of the foot. The flexor hallucis longus is immediately medial to the peroneus brevis. The fascia investing these muscles is deep to the deep fascia; it separates them into peroneal and deep flexor compartments. The flexor hallucis longus remains muscular down to the ankle joint.

 

Distal to the tarsal canal lies the anterior part of the subtalar joint and the talocalcaneonavicular joint. This complex joint consists of a ball (the head of the talus) articulating with a socket (the concave posterior aspect of the navicular, the concave anterior end of the superior surface of the calcaneus, and the spring ligament—short plantar calcaneonavicular ligament—that connects the two bony elements of the socket). From the lateral side, the talonavicular part of the joint appears nearly vertical. From a dorsal point of view, the joint runs transversely across the foot, in line with the calcaneocuboid joint.

Distal to the sinus tarsi lies the calcaneocuboid joint, formed by the

anterior end of the calcaneus and the posterior aspect of the cuboid. From the lateral side, the joint looks vertical. A more dorsal view shows that it runs transversely across the foot in line with the talonavicular joint.

Once the sinus tarsi has been defined, all these joints become accessible if surgery remains on bone and the surgeon is aware of the different planes of the joints.

 

 

 

Figure 12-66 Osteology of the posterolateral aspect of the foot and ankle.

 

Dorsal Approaches to the Middle Part of the Foot‌

 

 

The middle part of the foot extends from the calcaneocuboid and talonavicular joints to the tarsometatarsal Lisfranc joints. All these bones and joints are superficial and can be approached directly by dorsal, medial,

lateral, and plantar approaches. Operations in this area (which are performed rarely) usually involve surgery on the insertions of the four powerful muscles that, together, are responsible for controlling inversion and eversion of the foot. These muscles are the tibialis anterior, which inserts into the medial surface and undersurface of the medial cuneiform bone, and into the adjoining part of the base of the first metatarsal bone; the peroneus longus, which inserts into the lateral side of the medial cuneiform bone; the peroneus brevis, which inserts into the base of the lateral side of the fifth metatarsal bone; and the tibialis posterior, which inserts into the tuberosity of the navicular bone, the inferior surface of the medial cuneiform bone, the intermediate cuneiform bone, and the bases of the second, third, and fourth metatarsal bones (see Figs. 12-55, 12-58, and 12-62).

The middle part of the foot is the target of various specialized procedures for the treatment of muscle imbalance, mobile flatfoot, and an accessory navicular bone. It is also approached for open reduction and internal fixation of fractures in and around Lisfranc joint, and for local tarsal fusion. Only the general surgical approaches are considered here, because the details of operative technique and indications are beyond the scope of this book.

 

Position of the Patient

 

Place the patient supine on the operating table. Dorsomedial approaches and medial approaches are carried out with the leg in its natural position of slight external rotation, whereas dorsolateral approaches require internal rotation of the limb, which is achieved by placing a sandbag under the buttock. For all procedures, 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 Incisions

Landmarks

To palpate the first metatarsal cuneiform joint, feel along the medial border of the foot in a distal to proximal direction. The first metatarsal flares slightly at its base to meet the first cuneiform.

Continue moving proximally along the medial border of the foot to reach the tubercle of the navicular. The medial side of the talar head is immediately proximal to the navicular. It can be located by inverting and

everting the forepart of the foot. The motion that occurs between the talus and the navicular is palpable (Fig. 12-67).

Palpate the base of the fifth metatarsal by feeling along the lateral side of its shaft in a distal to proximal direction until its flared base is reached; this is the styloid process, into which the peroneus brevis muscle inserts (Fig. 12-69).

Incisions

Make a longitudinal incision directly over the area to be exposed. Use a dorsomedial incision to expose the talonavicular joint, the navicular-medial cuneiform joint, and the first metatarsocuneiform joint, and to reveal the insertions of the tendons of the tibialis anterior and tibialis posterior muscles (see Fig. 12-67). Use a dorsolateral incision to expose the calcaneocuboid joint and the base of the fifth metatarsal (see Figs. 12-63 and 12-69).

If access to both the medial and lateral sides of the tarsus is required, it is better to make two separate longitudinal incisions centered over the structures to be explored. Separate incisions nearly always are required for the open reduction in fractures of Lisfranc joint.

Transverse incisions are used best for wedge tarsectomy.

 

Internervous Plane

 

There are no internervous planes in these approaches. Longitudinal incisions avoid damaging cutaneous nerves. Certain major reconstructive operations, such as wedge tarsectomy, necessarily cut cutaneous nerves, leaving portions of the dorsum of the foot partially anesthetic.

 

Surgical Dissection

 

Cut down directly onto the structures that are to be exposed, taking care to avoid any cutaneous nerves that can be identified. Try to make sure that skin flaps are as thick as possible; minimize retraction as much as possible. The structures of the dorsum of the foot nearly all are subcutaneous. Take care to avoid damaging the insertions of the four powerful invertors and evertors of the foot (Figs. 12-68 and 12-70).

 

 

Figure 12-67 Incision for exposure of the middle part of the foot. Make a longitudinal incision directly over the area to be exposed. A dorsomedial incision exposes the talonavicular joint, the navicular-medial cuneiform joint, and the first metatarsocuneiform joint.

 

 

Figure 12-68 Develop the skin flaps. Note the insertions of the tibialis anterior and posterior muscles. Incise the joint capsules of the talonavicular joint, the navicular-medial cuneiform joint, and the first metatarsocuneiform joint according to the demands of the surgery.

 

 

Figure 12-69 A dorsolateral incision exposes the calcaneocuboid joint and the base of the fifth metatarsal.

 

 

Figure 12-70 Develop the skin flaps on the lateral side of the middle part of the foot. Note the tendon of the peroneus brevis as it inserts into the base of the fifth metatarsal. The joint capsule of the calcaneocuboid joint can be incised, if necessary.

 

How to Enlarge the Approach

 

These approaches can be extended proximally. On the lateral side, extend the incision posteriorly and then up behind the posterior border of the lateral malleolus; this exposes not only the lateral side of the ankle joint but also the posterior part of the subtalar joint and the calcaneocuboid joint (see sections describing the posterolateral approach to the ankle and lateral approach to the hindpart of the foot).

On the medial side, extend the incision up behind the medial malleolus, curving it to a point midway between the medial malleolus and the Achilles tendon. This extension exposes those structures that pass around the back of the medial malleolus. It is used commonly in the treatment of clubfoot, but its safety is controversial; the neurovascular

bundle must be protected (see the section regarding the posteromedial approach to the ankle).

 

Dorsal Approaches to the Metatarsophalangeal Joint of the Great Toe‌

 

 

The dorsal approach can be employed for most of the surgeries to the metatarsophalangeal joint of the great toe for the treatment of bunions or hallux rigidus.

Its use includes the following:

1. Excision of metatarsal exostosis (bunionectomy)

2. Distal metatarsal osteotomy

3. Excision of the proximal part of the proximal phalanx

4. Soft tissue correction of hallux valgus, including reefing procedures, tenotomies, and muscle reattachments

5. Arthrodesis of the metatarsophalangeal joint

6. Insertion of total joint replacements

7. Dorsal wedge osteotomy of the proximal phalanx in cases of hallux rigidus

The skin overlying a bunion may be red, thin, and inflamed. In extreme cases, frank ulceration with associated infection may occur. A careful assessment of the skin and vascular state of the foot is mandatory as part of the preoperative workup.

 

Position of the Patient

 

Place the patient supine on the operating table. After exsanguination, use a tourniquet placed midthigh. Alternatively, used a soft rubber bandage to exsanguinate the foot, then wrap the leg tightly just above the ankle (see Fig. 12-1).

 

Landmarks and Incision

 

Palpate the head of the first metatarsal bone and the metatarsophalangeal joint, which are on the ball of the foot and its medial border. In cases of

bunion, the metatarsal head is prominent medially.

Palpate the extensor hallucis longus tendon on the dorsum of the foot. When it is tight, it stands out when the great toe is passively flexed in the plantar direction. In most cases of hallux valgus, it is displaced laterally.

Begin the dorsal incision just proximal to the interphalangeal joint and just medial to the tendon of the extensor hallucis longus muscle. Extend the incision proximally, parallel, and just medial to the tendon of the extensor hallucis longus. Finish about 2 to 3 cm proximal to the metatarsophalangeal joint. Note that the final incision is straight (Fig. 12-71).

The dorsal incision avoids cutting through the thin, frequently atrophic skin overlying the medial aspect of the first metatarsal osteophyte. The disadvantage of the incision is that more soft tissue dissection is required to carry out procedures on the medial capsule. Terminal cutaneous branches of the deep peroneal nerve and saphenous nerve are also more at risk.

 

Internervous Plane

 

There is no true internervous plane. The bone is subcutaneous; the two tendons that lie close to the dissection—the extensor hallucis longus and the adductor hallucis—receive their nerve supply proximal to this approach and cannot be denervated by it.

 

Superficial Surgical Dissection

 

Divide the deep fascia in line with the incision, and retract the tendon of the extensor hallucis longus muscle laterally. To enter the joint, incise the dorsal aspect of the joint capsule. The type and position of the capsulotomy depends on the procedure to be performed (Figs. 12-72 and 12-73).

 

Deep Surgical Dissection

 

Incise the periosteum of the proximal phalanx on the first metatarsal bone longitudinally. Using both sharp and blunt dissections; strip the coverings of the bone, taking care not to damage the tendon of the flexor hallucis longus muscle, which lies in a fibro-osseous tunnel on the plantar surface at the proximal phalanx, between the sesamoid bones. The extent of the deep dissection depends on the procedure to be carried out. Strip only a

minimum of periosteum of the bone. Do not strip all the soft tissue attachments off the first metatarsal if the distal osteotomy of that bone is to be performed, as the metatarsal head may be rendered avascular by stripping.

 

 

 

Figure 12-71 Dorsal incision for the approach to the metatarsophalangeal joint of the great toe. Note that the tendon of the extensor hallucis longus is displaced laterally and that the sensory nerve to the medial aspect of the great toe runs parallel to the incision. Note that the great toe is framed by branches of the saphenous nerve medially and the deep peroneal nerve laterally.

 

 

Figure 12-72 Develop the skin flaps. Divide the deep fascia in line with the skin incision, and retract the tendon of the extensor hallucis longus laterally.

 

 

Figure 12-73 Incise the joint capsule dorsally, and remove as much of the capsule as necessary depending on the procedure to be performed.

 

 

Dang

 

 

The tendon of the extensor hallucis longus muscle, which lies on the lateral edge of the wound, should not be cut during the approach. In most cases of bunion, the tendon bowstrings laterally across the metatarsophalangeal joint and is lateral to the incision. Protect the dorsal digital nerve if it can be seen along the line of the incision (see Figs. 12-71 and 12-74). The tendon of the flexor hallucis longus muscle is vulnerable at the base of the proximal phalanx. The tendon lies in a groove on the plantar surface of the proximal phalanx so close to the periosteum that, if care is not taken, it may be damaged during stripping. Note that this tendon is often displaced laterally in patients with hallux valgus (see Fig. 12-54).

How to Enlarge the Approach

 

Careful and systematic stripping of the bone provides an adequate view of the joint. The approach cannot be extended usefully to other joints in the foot, but may be extended proximally to access the shaft of the first metatarsal bone.

 

Dorsomedial Approaches to the Metatarsophalangeal Joint of the Great Toe‌

 

 

The dorsomedial approach makes possible most surgeries to the metatarsophalangeal joint of the great toe for the treatments of bunions or hallux rigidus.

The dorsomedial skin incision provides access to the exostosis on the metatarsal head without much skin retraction; it does have drawbacks, however. The bursa covering the exostosis may have become inflamed, complicating the surgery. As well, the skin on the medial aspect of the metatarsophalangeal joint is thinner than on the dorsum of the joint, and may not heal as well.

The major advantage of the skin incision is that it gives direct access to the exostosis and is anatomically farther away from the terminal branches of the saphenous nerve.

Its use includes the following:

1. Excision of exostosis of the first metatarsal (bunionectomy)

2. Excision of the proximal part of the proximal phalanx of the hallux (Keller procedure)

3. Procedures on the medial joint capsule, including reefing and V-Y plasties

4. Arthrodesis of the metatarsophalangeal joint

5. Insertion of total joint replacements

6. Dorsal wedge osteotomy of the proximal phalanx in cases of hallux rigidus

 

Position of the Patient

Place the patient supine on the operating table. After exsanguination, place a tourniquet on the middle of the thigh. Alternatively, use a soft rubber bandage to exsanguinate the foot, then wrap the leg tightly just above the ankle (see Fig. 12-1).

 

Landmarks and Incision

 

The head of the first metatarsal bone and the metatarsophalangeal joint are palpable on the ball of the foot and on its medial border. In cases of bunion, the metatarsal head is prominent medially.

Palpate the extensor hallucis longus tendon on the dorsum of the foot. When it is tight, it stands out upon passive flexion of the great toe in the plantar direction.

Begin the dorsomedial incision just proximal to the interphalangeal joint on the medial aspect of the great toe. Curve it over the medial aspect of the metatarsophalangeal joint, remaining medial to the tendon of the extensor hallucis longus muscle. Then, curve the incision back by cutting along the medial aspect to the shaft of the first metatarsal, finishing some 2 to 3 cm from the metatarsophalangeal joint (Fig. 12-74).

 

Internervous Plane

 

There is no true internervous plane. The bone is subcutaneous; the two tendons close to the dissection—the extensor hallucis longus and the abductor hallucis—receive their nerve supply proximal to this approach, thus cannot be denervated by it.

 

Superficial Surgical Dissection

 

Incise the deep fascia in line with the incision. Then approach the dorsomedial aspect of the metatarsophalangeal joint using sharp dissection. The dorsal digital branch at the medial cutaneous nerve may be visible in the upper flap of the wound. Retract it laterally with the skin flap on the lateral edge of the wound. Next, make an incision into the joint capsule. The positioning of the incision depends on the surgical procedure to be carried out. A longitudinal incision or U-shaped incision is standard. Ensure that you leave the capsule attached to the proximal end of the proximal phalanx (Figs. 12-75 and 12-76).

 

 

Figure 12-74 Dorsomedial skin incision for the medial approach to the metatarsophalangeal joint of the great toe. Note the proximity of the dorsal digital nerve to the incision.

 

 

 

Figure 12-75 Incise the deep fascia. Develop a joint capsule flap. Protect the dorsal digital branch of the medial cutaneous nerve.

 

Deep Surgical Dissection

 

Incise the periosteum of the proximal phalanx and the first metatarsal bone longitudinally. Using sharp and blunt instruments, strip the coverings of the bone, taking care not to damage the tendon of the flexor hallucis

longus muscle, which lies in a fibro-osseous tunnel of the plantar surface of the proximal phalanx, between the sesamoid bones. The extent of deep dissection depends on the procedure. Strip only a minimum of periosteum of the bone. Take great care not to strip all the soft tissue attachments of the first metatarsal bone if the distal osteotomy of that bone is to be performed, because the metatarsal head may be rendered avascular by stripping.

 

 

Dang

 

 

The tendon of the extensor hallucis longus muscle, which lies on the lateral edge of the wound, should not be cut during the approach. Indeed, in cases of bunion, the tendon bowstrings laterally across the metatarsophalangeal joint and is considerably more lateral to the incision. Protect the dorsal digital nerve if it can be seen (see Figs. 12-71 and 12-74).

 

 

 

Figure 12-76 Make a U-shaped incision into the joint capsule, leaving the capsule attached to the proximal end of the proximal phalanx.

 

The tendon of the flexor hallucis longus muscle is vulnerable as you strip tissue from the base of the proximal phalanx. The tendon lies in a groove on the plantar surface of the proximal phalanx so close to the

periosteum that, if care is not taken, it may be damaged during stripping. Note: This tendon is usually displaced laterally in patients with hallux valgus (see Fig. 12-54).

 

How to Enlarge the Approach

 

Careful and systematic stripping of the structures of the bone provides an adequate view of the joint. The approach cannot be extended usefully to other joints in the foot, but may be extended proximally for access to the shaft of the first metatarsal.

 

Dorsolateral Approach for Bunion Surgery‌

 

 

The dorsolateral approach for bunion surgery allows access to those structures present on the lateral aspect of the metatarsophalangeal joint of the hallux. It is used almost exclusively for soft tissue corrective procedures in cases of hallux valgus.

Its uses include the following:

1. Tenotomy of the adductor hallucis tendon

2. Release of the lateral (fibular) sesamoid bone and, rarely, excision of that bone

3. Division of the transverse metatarsal ligament

Soft tissue procedures in hallux valgus are often accompanied by other surgical procedures: Classically, first metatarsal osteotomies. This surgical approach, therefore, is often combined with dorsomedial approaches to the metatarsophalangeal joint of the hallux.

Soft tissue procedures, in isolation, are contraindicated in advanced arthrosis of the metatarsophalangeal joint, spasticity of any type, and when the distal metatarsal proximal phalangeal angle is greater than 15 degrees. As with all procedures on the distal part of the foot, a preoperative assessment of the vascularity of the foot is mandatory.

 

Position of the Patient

 

Place the patient supine on the operating table. After exsanguination, use a tourniquet placed on the middle of the thigh. Alternatively, use a soft

rubber bandage to exsanguinate the foot, then wrap the leg tightly just around the ankle (see Fig. 12-1).

 

Landmarks and Incision

 

Palpate the head of the first metatarsal bone and the metatarsophalangeal joint on the ball of the foot and along its medial border. Palpate the extensor hallucis longus tendon on the dorsum of the foot. If you flex the toe passively in the plantar direction, the tendon stands out, making identification easier.

Make a 4- to 5-cm longitudinal incision on the dorsal aspect of the foot in the first web space. Center the incision between the first and second metatarsal heads. The incision should extend some 2 cm beyond the metatarsophalangeal joints of the hallux and second (index) toe (Fig. 12-77).

 

 

 

Figure 12-77 Make a 4- to 5-cm longitudinal incision on the dorsal aspect of the foot in the first web space. Center the incision between the first and second metatarsal heads.

 

Internervous Plane

 

There is no internervous plane. The only muscle involved in the approach

—adductor hallucis—receives its nerve supply well proximal to the surgical field, thus the muscle is not denervated by the approach. Terminal branches of the deep peroneal nerve supply skin in the region of the first web space. Care must be taken to preserve these nerves so as not to denervate the skin, creating an area of anesthesia postoperatively.

 

Superficial Surgical Dissection

 

Deepen the incision in the line of the skin incision through subcutaneous tissue and fat. Continue dissection to expose and then incise the adventitious bursa present between the first and second metatarsal heads (Fig.12-78).

 

Deep Surgical Dissection

 

Insert a self-retaining retractor between the first and second metatarsal heads. Identify the tendon of adductor hallucis as it inserts jointly into the lateral sesamoid bone and the lateral aspect of the proximal phalanx of the hallux (Fig. 12-79). Using a knife blade, develop a plane between the metatarsal head dorsally and the lateral (fibular) sesamoid bone plantarly (Fig. 12-80A). Develop this plane until the blade strikes the base of the proximal phalanx. Turn the blade laterally and plantarward to release the adductor tendon from the base of the proximal phalanx. Withdraw the blade in the same plane between the metatarsal head and the sesamoid, dividing the remainder of the capsule running between the sesamoid bone and the metatarsal. Identify the cut end of the adductor hallucis tendon and dissect it carefully, proximally, until the muscle fibers of the adductor hallucis are found. At this stage, you will be able to see the lateral (fibular) sesamoid clearly (Fig. 12-80B).

 

 

Figure 12-78 Deepen the incision in the line of the skin incision through subcutaneous tissue and fat. Continue dissection to expose and then incise the adventitious bursa present between the first and second metatarsal heads.

 

 

 

Figure 12-79 Insert a self-retaining retractor between the first and second metatarsal heads. Identify the tendon of adductor hallucis as it inserts jointly into the lateral sesamoid bone and the lateral aspect of the proximal phalanx of the hallux.

 

 

Figure 12-80 A: Using a knife blade, develop a plane between the metatarsal head dorsally and the lateral (fibular) sesamoid bone plantarly. B: Identify the cut end of the adductor hallucis tendon and dissect it carefully, proximally, until the muscle fibers of the adductor hallucis are found. At this stage, you will be able to see the lateral (fibular) sesamoid clearly.

 

Reinsert the self-retaining retractor deeply, spreading the first and second metatarsal heads apart. This places the transverse metatarsal ligament, which passes from the second metatarsal bone into the lateral (fibular) sesamoid, under tension. Carefully divide the ligament with sharp dissection, noting that the common digital nerve and the artery to the first web space are immediately underneath the structure.

 

 

Dang

 

Terminal branches of the deep peroneal nerve may be injured in superficial surgical dissection. Staying in the midline of the web space will reduce the risk of injuring these important cutaneous nerves. Careless incision of the transverse metatarsal ligament may injure the digital nerve that lies immediately underneath. This risk can be minimized if the structure is identified and stretched using the self-retaining retractor.

 

How to Enlarge the Approach

 

This approach cannot be usefully extended either proximally or distally. Its use is exclusively confined to soft tissue procedures on the lateral aspect of the metatarsophalangeal joint of the hallux.

 

Dorsal Approach to the Metatarsophalangeal Joints of the Second, Third, Fourth, and Fifth Toes‌

 

 

The dorsal approach, which exposes the metatarsophalangeal joints of the second, third, fourth, and fifth toes, avoids incision of the plantar skin of the foot. Most plantar approaches scar the weight-bearing skin, violating a basic surgical principle.

The uses for the approach include the following:

1. Excision of metatarsal heads

2. Distal metatarsal osteotomy

3. Partial proximal phalangectomy

4. Fusion of metatarsophalangeal joints (rare)

5. Capsulotomy of metatarsophalangeal joints

6. Muscle tenotomy

7. Neurectomy

 

Position of the Patient

 

Place the patient supine on the operating table. Position a bolster under the thigh to flex the knee and allow the foot to lie with its plantar surface on the table (Fig. 12-81).

Landmarks and Incision

Landmarks

To palpate each metatarsal head, place a thumb on the plantar surface and an index finger on the dorsal surface of the foot. Skin callosities under the heads indicate that the area concerned is bearing an unaccustomed amount of weight and indicating pathology in the weight distribution around the foot. Palpate the tendons of the extensor digitorum longus muscle on the dorsal aspect of the foot.

Incision

Make a 2- to 3-cm longitudinal incision over the dorsolateral aspect of the affected metatarsophalangeal joint. The incision should run parallel with, but just lateral to, the long extensor tendon (Fig. 12-82). If two adjacent joints need to be exposed, make the incision between them. Alternatively, a transverse dorsal incision may be made over the joints.

 

 

Figure 12-81 Position of the patient for approaches to the toes.

 

 

Figure 12-82 Make a 2- to 3-cm longitudinal incision over the dorsolateral aspect of the affected metatarsophalangeal joint.

 

Internervous Plane

 

There is no true internervous plane for any of these metatarsophalangeal approaches. The approaches are well dorsal to the plantar nerves and vessels, the key neurovascular structures in this area. Take care to avoid cutting the dorsal digital nerves, branches of which may cross the operative field.

 

Superficial Surgical Dissection

 

Incise the deep fascia in line with the incision, and retract the long extensor tendon to reveal the dorsal aspect of the metatarsophalangeal joint (Fig. 12-83). Often, an extensor tenotomy or lengthening is performed at the same time as the operation on the joint. In this case, divide the extensor

tendon in a “Z” fashion rather than retracting it. If two joints are being exposed, retract the tendon laterally to gain access to the adjacent joint.

 

Deep Surgical Dissection

 

Incise the dorsal capsule of the metatarsophalangeal joint longitudinally to enter the joint (Figs. 12-84 and 12-85).

 

 

Dang

 

 

The long extensor tendon should be protected during the procedure.

At the level of the metatarsophalangeal joints, the plantar nerves and vessel lie between the metatarsal heads, beneath the deep transverse metatarsal ligament. As long as the dissection remains on the dorsal aspect of the ligaments, the nerves are safe. Dissection around the metatarsal heads and proximal phalanges must be carried out so as to avoid damage to the nerves and vessel that supply the weight-bearing skin of the toes (see Fig. 12-58).

 

 

 

Figure 12-83 Incise the deep fascia in line with the incision on the medial side of the long extensor tendon.

 

 

Figure 12-84 Expose the dorsal capsule of the metatarsophalangeal joint. Make a longitudinal incision into the capsule.

 

 

 

Figure 12-85 Retract the joint capsule to expose the metatarsophalangeal joint.

 

Dorsal Approach for Morton Neuroma ‌

The dorsal approach to the web space allows pathology of web spaces to be explored. By far, the most common use of this approach is in the identification and excision of Morton neuromas. The approach is most commonly used for exploration of the cleft between the third and fourth toes, the most common site for Morton neuroma. Less common uses include drainage of web space infections, which are curiously much rarer in the foot than the hand.

 

Position of the Patient

 

Place the patient supine on the operating table. Apply a tourniquet either at the midpoint of the thigh or just above the ankle after the leg has been exsanguinated. Alternatively, use a soft rubber bandage to exsanguinate the foot, then use the bandage as a tourniquet at the ankle (see Fig. 12-81). Place a firm wedge or several pillows under the patient’s thigh to flex the knees, so that the foot lies flat on the operating table.

 

Landmarks and Incision

 

Palpate the metatarsophalangeal joint of the two adjacent toes by passively flexing and extending them. Separate the two toes of the affected web space. The easiest way to do this is to wrap a gauze swab around the adjacent toes and use it to pull the two toes apart. Make a dorsal longitudinal incision over the center of the web space starting at the distal end of the web and extending proximally some 2 to 3 cm beyond the level of the metatarsophalangeal joints (Fig. 12-86).

 

Internervous Plane

 

There is no internervous plane. No muscles or tendons are encountered in the approach.

 

Superficial Surgical Dissection

 

Incise the deep transverse metatarsal ligament in line with the skin incision initially with blunt dissection and then by opening a pair of scissors with the blades in the longitudinal plane. Division of the deep transverse metatarsal ligament will expose the neurovascular bundle (Figs. 12-87 and 12-88). The neuroma, if one is present, often bulges into the wound. To make it more prominent, apply digital pressure to the space between the

metatarsal heads, pushing your finger up on the plantar surface of the foot (see Fig. 12-88).

This surgical approach not only exposes the neuroma but also divides the deep transverse metatarsal ligament that many surgeons believe is the cause of the irritation in neuroma pathology.

 

 

 

Figure 12-86 Make a dorsal longitudinal incision over the center of the web space starting at the distal end of the web and extending proximally some 2 to 3 cm beyond the level of the metatarsophalangeal joints.

 

 

Figure 12-87 Incise the fascia in line with the skin incision.

 

 

Dang

 

 

The only danger in an approach to a single cleft is the digital nerve and vessel that are the target of the approach. Take care, however, to avoid cutting any dorsal cutaneous nerves that run under the incision.

The arterial supply to the toes runs closely with the nerves. If more than one cleft must be explored, take care to avoid disrupting the arterial supplies of the toes. Accidental incision of one digital artery does not render a toe ischemic, but if the second digital artery to the same toe is incised in the next web space, ischemia may result (see Fig. 12-58).

Excising a neuroma from a web space usually leaves the weight-bearing surface of the affected toes at least partially anesthetic, but trophic changes do not occur.

 

How to Enlarge the Approach

 

The approach is rarely enlarged and is used almost exclusively for specific web space pathology.

 

 

Figure 12-88 Incise the deep transverse metatarsal ligament in line with the skin and fascial incision to reveal the neurovascular bundle.

 

Applied Surgical Anatomy of the Foot ‌

 

Overview

 

Surgery of the foot often is undertaken to correct bony abnormalities. All the bones of the foot can be approached dorsally; dorsal approaches usually are better than plantar approaches for two major reasons:

1. The critical neurovascular structures in the forepart of the foot all are on the plantar side of the metatarsal bones, so they remain protected.

2. Dorsal incisions avoid cutting through the specialized weight-bearing skin of the sole of the foot.

In pathologic situations in which abnormal skin lies over bones that protrude (e.g., metatarsalgia), a plantar approach may have to be used and the abnormal skin excised.

Although the dorsal anatomy is the critical surgical anatomy of the foot, the plantar anatomy includes its key neurovascular structures. Knowledge of the latter allows the surgeon to explore wounds in the sole

of the foot, which do not mimic any described surgical approach. For these reasons, the anatomy of the sole of the foot also is described in the following section.

 

Anatomy of the Dorsum of the Foot

 

The skin of the dorsum of the foot is comparatively thin and loose. Distally, the lines of cleavage (also called relaxed skin tension lines, especially by plastic and aesthetic surgeons) run roughly transversely. The loose skin, which facilitates retraction, accounts for the enormous amount of dorsal swelling that can occur after foot trauma.

 

Nerve Supply

 

Branches of three cutaneous nerves run right under the skin of the dorsum of the foot: The medial side houses the branches of the saphenous nerve; most of the dorsum of the foot is supplied by the dorsal cutaneous branches of the superficial peroneal nerve; and the lateral side of the foot is supplied by the sural nerve. The first web space is supplied by branches of the deep peroneal nerve. Numbness in the first web space is the earliest sign of a deep peroneal nerve lesion in the anterior compartment of the leg (see Figs. 12-58, 12-74, 12-82, and 12-86).

 

Superficial Veins

 

The veins are arranged in a dorsal venous arch. The medial side drains into the long saphenous vein; the lateral side drains into the short saphenous vein. Superficial veins, of course, must be on the dorsum of the foot, because they would collapse under the force of ordinary weight bearing if they were on the sole.

 

Tendons

 

Two sets of tendons lie immediately deep to the cutaneous nerves: Those of the extensor digitorum longus and extensor digitorum brevis muscles and those of the extensor hallucis longus and extensor hallucis brevis muscles. The extensor digitorum tendons insert into the dorsal extensor expansion of the lateral four toes, an arrangement that is identical to that in the fingers. Frequently, these tendons cross-communicate in the forepart of the foot. The great toe, similar to the thumb, has no dorsal extensor

expansion (see Fig. 12-58).

 

Deep Artery

 

The artery of the dorsum of the foot, the dorsalis pedis artery, runs forward beneath the tendon of the extensor hallucis brevis muscle before disappearing into the first intermetatarsal space (see Fig. 12-59).

 

Sole of the Foot

Skin

The skin of the sole of the foot is highly specialized, tough, and resilient. It responds to abnormal stresses by hypertrophying in the keratinized layer, forming callosities. In cases of severe metatarsalgia, the skin over the protruding metatarsal heads becomes thin and attenuated. In Fowler procedure (a transverse incision), the lips of pathologic skin are removed, and the thicker, normal skin is sutured back into its correct position.6,7 The skin also may atrophy in patients with ischemic or neuropathic conditions.

 

Deep Fascia

 

The deep fascia of the sole is similar to the deep palmar fascia of the hand; it also may suffer Dupuytren contracture. The fascia is much thicker in its central parts and thinner where it covers the intrinsic muscles of the hallux and little toe. Its central part, the plantar aponeurosis, originates from the medial tubercle of the calcaneus and runs forward to attach to the proximal phalanges of each of the toes.

The attachment of the plantar aponeurosis to the medial tubercle of the calcaneus often is a site for the inflammatory degeneration that produces a painful heel. The point of maximal tenderness in this condition corresponds to the anatomic insertion of the plantar aponeurosis. On rare occasions, this condition, which is known as plantar fasciitis (“policeman’s heel”), may necessitate surgical detachment of the origin of the fascia.

Medial and lateral fibrous septa originate from the medial and lateral borders of the plantar fascia to attach to the first and fifth metatarsal bones. These septa divide the foot into three compartments, much as the septa do in the hand. The compartments may limit areas of infection within the foot.

 

First Layer of Muscles

The superficial layer consists of three muscles: The flexor digitorum brevis, abductor hallucis, and abductor digiti minimi.

The flexor digitorum brevis arises mainly from the plantar aponeurosis and partly from the medial calcaneal tubercle. It divides into four tendons that insert into the middle phalanx of the lateral four toes and flexes the toes independent of the position of the ankle.

The abductor hallucis takes origin from the medial tubercle of the calcaneus, inserts into the medial side of the proximal phalanx of the great toe, and abducts the great toe. It is the only muscle whose action tends to oppose the deformity of hallux valgus (see Fig. 12-54).

 

Superficial Nerves and Vessels

 

The medial and lateral plantar arteries and nerves lie between the first and second layers of muscle. They are relatively superficial, but, as in the hand, rarely are injured, because of the toughness of the overlying plantar fascia.

 

Second Layer of Muscles

 

The second layer of muscles consists of the long flexor tendons (the flexor hallucis longus, flexor digitorum longus, and flexor accessorius), which are critical in maintaining the longitudinal arch of the foot (see Figs. 12-55 and 12-56). Helping these muscles are the lumbricals, which arise from the tendons of the flexor digitorum longus. As they do in the hand, the lumbricals flex the metatarsophalangeal joints while they keep the interphalangeal joint extended. Weakness results in clawing of the toes, producing the equivalent in the foot of the intrinsic minus hand. A persistent extension deformity of the metatarsophalangeal joint eventually causes this joint to undergo subluxation, and the metatarsal head has to bear weight that no longer is distributed to the displaced toe during toe-off in walking. Pain (metatarsalgia) is the result.

 

Third Layer of Muscles

 

The third layer of muscles consists of the flexor hallucis brevis, adductor hallucis, and flexor digiti minimi brevis.

The flexor hallucis brevis inserts into the base of the proximal phalanx of the great toe via medial and lateral sesamoid bones. The medial sesamoid also receives slips from the abductor hallucis, and the lateral

sesamoid from the adductor hallucis. The sesamoid bones may be displaced in cases of hallux valgus, with the lateral sesamoid moving to a position between the first and second metatarsal bones. If that happens, the lateral sesamoid can block mechanically the realignment of the first ray. The joint between the sesamoid bones and the metatarsal head may degenerate and become painful.

The adductor hallucis, which inserts into the proximal phalanx via the lateral sesamoid bone, is the most important deforming force in hallux valgus. Many operations for this condition involve detaching the muscle from its insertion and reinserting it into the head of the metatarsal so that it can act as a dynamic corrector of metatarsus varus.

 

Fourth Layer of Muscles

 

The fourth and deepest layer of muscles consists of the interosseous muscles attached to the metatarsal bones, and two tendons, those of the peroneus longus and tibialis posterior muscles, which are major supports of the longitudinal arch of the foot.

 

REFERENCES

1. COLONNA PC, RALSTON EL: Operative approaches to the ankle joint.

   Am J Surg. 1951;82:44–54.

2. GATELLIER J, CHASTANG P: Access to the fractured malleolus with piece chipped off at back. J Chir (Paris). 1924;24:513.

3. KOENIG F, SCHAEFER P: Osteoplastic surgical exposure of the ankle joint: 41st report of progress in orthopaedic surgery. Chir. 1929;215:196–207.

4. RUEDI TP, MURPHY WM: AO Principles of Fracture Management. Munich: Thieme; 2001.

5. WHITE JW: Torsion of the Achilles tendon: its surgical significance.

   Arch Surg. 1943;46:784.

6. FOWLER AW: A method of forefoot reconstruction. J Bone Joint Surg Br. 1959;41:507–513.

7. KATES A, KESSEL L: Arthroplasty of the forefoot. J Bone Joint Surg Br.

1967;49:552–557.

 

 

∗Lisfranc, who was one of Napoleon’s surgeons, is remembered best for his description of an amputation for trauma through the tarsometatarsal joint. The joint

and injuries connected with it carry his name.