Anatomy

The ankle is a hinge joint composed of the articular surfaces of the lower portion of the tibia, talus, and medial and lateral malleoli (Fig. 12-1). The stability of this joint or “mortise” is maintained by the malleoli and their ligaments, which grasp the talus and prevent medial and lateral displacement. The talus and socket are both broader in front, an arrangement that provides maximum stability when the ankle is in dorsiflexion or neutral, and this prevents posterior displacement. Only movements of dorsiflexion and plantar flexion occur at the ankle.

Fig. 12-1 Bones of the ankle and heel. A, The talus is held in position in the mortise by the malleoli and ankle ligaments. B, The articular surface of the talus is wider anteriorly than posteriorly. The ankle is therefore more stable in neutral or slight dorsiflexion when the wider anterior portion of the talus fits in the mortise. It is unstable in plantar flexion. Wearing high-heeled shoes may therefore lead to chronic ankle and calf pain. Eversion and inversion movements take place in the subtalar (talocalcaneal) joint.

The foot is composed of 26 bones, 12 of which are components of the medial and lateral longitudinal arches (Fig. 12-2). Strong fascial supports maintain these arches and prevent collapse (Fig. 12-3). Eversion and inversion movements of the foot take place in the hindfoot at the subtalar joint. Injury or disease that affects this joint will cause pain in the region of the heel when walking on uneven or irregular surfaces. Abduction and adduction movements occur in the midfoot or midtarsal joints.

Fig. 12-2 Roentgenogram of the foot. N, Navicular; T, talus; CA, calcaneus; CU, cuboid; CN, cuneiforms, medial, intermediate, and lateral. The foot is divided into the forefoot (phalanges and metatarsals), midfoot (tarsals), and hindfoot (talus and calcaneus).

Fig. 12-3 The plantar fascia. It may be affected by Dupuytren’s contracture in a similar manner to the hand. It may also become inflamed, especially at the medial attachment to the calcaneus (plantar fasciitis).

During normal walking, when the heel strikes, the calcaneus everts to cushion impact. At the toe-off position, the heel then rolls into varus to provide power.

Flatfoot

Flatfoot is a common disorder that is defined as a depression or loss of the medial longitudinal arch of the foot. It is usually combined with valgus or eversion of the heel and abduction of the forefoot. An apparent flatfoot (“fat foot”) is present in many children up to the age of 2 years because of the presence of a fat pad in the area of the longitudinal arch. As the fat pad atrophies with weight bearing, the normal arch usually becomes visible. Flatfoot is usually one of two types: flexible or rigid. It occurs in conjunction with an accessory navicular bone in the foot, and it also results when a rupture of the posterior tibial tendon has occurred. It is also seen in the late stages of Charcot arthropathy, when collapse and reversal of the longitudinal arch can develop.

ClINICAL FEATURES

Symptoms are rare but may consist of pain, burning, and easy fatigability. With weight bearing, the heels are everted, and the forefoot appears pronated and abducted (Fig. 12-4). The child often “breaks down” the medial counter of the shoe. When it is not bearing weight, the foot often looks normal. Absence of the medial arch is apparent, and the foot is mobile without any fixed deformity. The child with flatfoot can usually form a good arch when asked to stand on tiptoe. The heel rolls into its usual varus position, and normal strength is apparent. A mild genu valgum (knock-knee) or internal tibial torsion may be present. With the heel inverted, passive dorsiflexion of the ankle will be limited if the heel cord is tight.

Fig. 12-4 Flatfoot deformity with eversion (valgus) of the heels and loss of the normal longitudinal arch.

A lateral roentgenogram taken with the foot bearing weight may reveal a loss of the normal arch and plantar flexion of the talus (Fig. 12-5). Some secondary bony changes may be present in the adult.

Fig. 12-5 Lateral weight-bearing roentgenogram revealing plantar flexion of the talus.

TREATMENT

The treatment of flexible flatfoot in the child is controversial. The disorder is considered a normal variant in most cases, and only reassurance is needed. The natural history is spontaneous correction in the majority of cases with maturity. Symptoms are rare during childhood and uncommon even in the adult with moderately severe deformity. Actually, most foot pain in young adults is caused by an abnormally high rather than an abnormally low arch. Shoe corrections and orthotics used for this condition are of uncertain benefit. An arch cannot be “created” by supporting it. Exercises are of doubtful value, except for those that stretch the tight heel cords (Fig. 12-6). These exercises cure many cases associated with heel cord contractures. A soft arch support may be tried if symptoms are present. Surgery is reserved for symptomatic cases but is rarely necessary. No treatment is needed in most cases.

Fig. 12-6 Heel cord stretching exercises. The legs are internally rotated; the forefeet are placed on a 2.5-cm board, and the patient leans forward.

Clubfoot

Congenital clubfoot, or talipes equinovarus, is a fixed deformity that is present at birth. It is frequently bilateral, and a hereditary factor is often present. The cause is unknown.

CLINICAL FEATURES

The deformity consists of three major components, none of which is passively correctable. This lack of correctability distinguishes clubfoot from other common foot deformities (which may be caused by intrauterine molding and usually resolve without treatment). The three components are equinus of the ankle and forefoot, varus of the heel, and adduction of the forefoot (Fig. 12-10). The medial border of the foot is concave, and the lateral border is convex.

Fig. 12-10 Bilateral clubfeet (talipes equinovarus).

TREATMENT

Early referral to an orthopedic specialist is needed, because treatment needs to begin within the first few days of life. The initial management consists of manipulation of the foot to stretch the contracted soft tissues, followed by the application of a corrective cast. The cast is changed at weekly intervals, and the foot is further manipulated until complete correction is obtained. This method of treatment frequently succeeds if it is begun immediately. Surgery is required when casting fails. The procedures range from simple heel cord lengthening to wide soft tissue releases.

Calcaneovalgus

Talipes calcaneovalgus is the most common neonatal foot disorder. It is characterized by excessive eversion and dorsiflexion of the foot. The cause is unknown, but positional compression in utero is likely. In contrast to clubfoot, the deformity is not fixed and may be easily overcorrected.

CLINICAL FEATURES

The deformity is easily diagnosed shortly after birth. Marked laxity of the ligaments of the foot and ankle is obvious, and the foot can often be dorsiflexed so that the toes touch the anterior aspect of the tibia (Fig. 12-11). The heel cord may appear to be severely stretched.

Fig. 12-11 Talipes calcaneovalgus.

Kohler’s Disease (Osteonecrosis of the Tarsal Navicular)

The tarsal navicular may undergo avascular necrosis similar to what occurs in other bones. The cause of all of these disorders is not completely understood, but interference with the circulation to the bone is thought to be the usual cause of the ischemia. The onset of this disorder is about the age of 5 years. A painful limp is the usual initial complaint. Local pain, tenderness, and swelling over the navicular bone are frequently present.

The roentgenographic appearance is usually characteristic. Flattening, sclerosis, and irregularity of the navicular are usually present (Fig. 12-12).

Fig. 12-12 Kohler’s disease (arrow).

Protection from excessive trauma, sometimes by the use of a short walking cast for 7 to 8 weeks, is sufficient treatment in most cases. Spontaneous recovery is the rule, and complete reossification of the navicular usually occurs within 2 to 3 years.

Ankle Sprains

The sprain is the most common of all ankle injuries and may be the most common injury in sports. Most of these (85%) involve the lateral ligament complex as a result of excessive inversion. Medial sprains involving the deltoid ligament are rare. The anterior talofibular (ATF) ligament is usually injured first in the typical lateral sprain (Fig. 12-13). More severe injuries involve the calcaneofibular (CF) ligament. Only rarely is the posterior talofibular ligament involved. The injuries are often graded I, II, and III, with I being mild and II being moderate. Grade III injuries are more severe, with instability resulting from rupture of the ATF and CF ligaments. Inversion (varus) sprains may also cause marked hemorrhage of the peroneal muscles and even peroneal nerve damage. The subtalar joint may also be injured.

Fig. 12-13 The lateral ankle ligaments, anterior and posterior talofibular (PTF) and calcaneofibular (CF). Also shown are the anterior inferior tibiofibular (AITF) ligament and the beginning of the interosseous membrane (IM).

Other ligamentous ankle injuries are much less common, but the anterior inferior tibiofibular (AITF) ligament, deltoid ligament, and interosseous membrane may be involved in eversion and rotational injuries. Damage to the tibiofibular syndesmosis is sometimes called a “high sprain” because of pain above the ankle from injury to the interosseous membrane. On rare occasions, the fibula may even be separated from the tibia.

CLINICAL FEATURES

The symptoms will depend on the severity of the injury. There is often a history of a “pop” at the time of injury. Mild sprains may cause only slight loss of function, but with more severe injuries, swelling and pain are significant and prohibit further use of the limb. Syndesmotic sprains often appear more benign because of minimal swelling. However, the pain and disability are greater than the clinical appearance would suggest, and the patient may be unable to bear weight.

Physical examination is important. Hemorrhage and local tenderness are present at the site of injury. Careful palpation can localize the site of damage. Tendon function should be assessed, and any bony tenderness should be noted. The clinical evaluation of stability is sometimes helpful since it may determine the course of treatment, although this part of the examination may need to be deferred because of pain. Stability of lateral injuries can be assessed by the anterior drawer and talar tilt tests (Fig. 12-14). The anterior drawer is the most reliable test and least painful in the acute stage. Positive test results indicate complete rupture of the ATF and CF ligaments and a grade III injury. Motor function should always be evaluated.

Fig. 12-14 Tests for ankle instability. A, Inversion stress test. B, Anterior drawer test with the foot slightly plantar flexed.

In syndesmotic injuries, the area of tenderness is more anterior and proximal. Dorsiflexion of the foot and compressing the ankle mortise (the “squeeze” test) may provoke pain, and the ankle may feel spongy.

Roentgenographic evaluation is always performed, and because the mechanism of injury that causes a lateral sprain is the same as that which causes an avulsion fracture of the base of the fifth toe, the film should include the fifth metatarsal base to rule out fracture of the small toe. If the injury is in a child or adolescent with open growth plates, tenderness over the fibular malleolus (even with normal roentgenographic findings) implies the more likely growth plate fracture rather than a lateral sprain, and a cast is usually necessary. Opinions vary on the usefulness of arthrograms, tenograms, and stress films (Fig. 12-15). A good clinical examination is usually sufficient to determine stability.

Fig. 12-15 A, Stress roentgenography of the ankle revealing severe lateral instability, with tilting of the talus. B, The anterior drawer test.

TREATMENT

Regardless of the severity, almost all sprains are treated nonoperatively. At first, all injuries are elevated, and a soft compression dressing is applied for comfort and to help control swelling. Ice (1 hour on, 1 hour off) is applied, and crutches are used for ambulation. Rest, ice, compression, and elevation (RICE) are continued for 1 to 2 days. Anti-inflammatory medication has been recommended in the past for these injuries because it was thought that suppressing the local inflammation could allow faster recovery from sprains and other similar soft tissue injuries. The use of these drugs under these circumstances has been the source of considerable debate, mainly because prostaglandins play important roles in the healing process and these medications block their production. The effects of NSAIDs on soft tissue healing are not clear, and any apparent benefits may only be because of their analgesic effects. Whether these drugs are helpful or harmful in these cases has not been determined. Crutches are frequently needed for 2 to 3 days. Heat is never used.

The next phase of treatment is rehabilitation, which includes early active range-of-motion exercises (circumduction) and weight bearing as tolerated (Fig. 12-16). “Alphabet” exercises (writing the alphabet in capital letters with the great toe) are begun, and in 4 to 5 days, exercise against resistance is added. Wrapping or bracing with a stabilizing orthosis may also be helpful. Static bicycling may be added after 1 week, along with fast walking.

Fig. 12-16 Ankle exercises. A-C, Range of motion (dorsiflexion, plantar flexion, circumduction, and writing the alphabet with the great toe). D-G, Strengthening exercises using a rubber strap (invertors, evertors, plantar flexors, and dorsiflexors). H, Static one-leg standing with eyes closed. I, Toe raises. J, Heel cord stretches. Each exercise is performed 10 to 15 times. Ice is applied for a few minutes before and after each exercise period, and the exercises are performed 3 times each day.

If the pain is particularly severe or the patient requires independence, a short leg walking cast may be applied for 2 to 4 weeks. A removable fracture cast boot is also a good option to control excessive pain.

Casting is used less frequently now because of concern over the temporary loss of motion and atrophy that occur, which require some time for restoration of function following cast removal. However, cast treatment has many advocates and should still be considered, especially in those patients who might require independent walking. Other options for painful sprains include various short leg orthoses that immobilize the ankle and foot, such as the ankle–foot orthosis (AFO). These are usually weight-bearing appliances that can be removed for exercise. They are worn for about 4 weeks. A compression stocking can help control swelling.

The treatment of severe sprains with instability remains somewhat controversial, but they are usually treated in the same manner as other sprains with a functional rehabilitation program. Although the results of surgical repair of unstable acute sprains are excellent, surgery is usually reserved for chronic instability in the high-level professional athlete or those with significant syndesmotic separations.

NOTE: Lateral sprains of any severity may also cause lingering symptoms for weeks and months. Some syndesmotic sprains take even longer to heal (55 days vs 35 days for lateral sprains), and heterotopic ossification may even develop in the interosseous membrane. (Unless symptoms occur, long-term results are not usually affected by such ossification.) If healing seems delayed, the following conditions should be considered: (1) talar dome fracture, (2) reflex sympathetic dystrophy, (3) chronic tendinitis, (4) peroneal tendon subluxation, (5) another occult fracture—such as that involving the anterior superior process of the calcaneus or the lateral process of the talus, (6) poor rehabilitation, and (7) the high sprain. Evaluation at this point should start by another clinical examination and simply repeating the plain roentgenograms (Fig. 12-17). CT, bone scan, or MRI may be indicated at a later time.

Fig. 12-17 Fracture of the anterior superior process of the calcaneus (arrow). This injury may not unite and cause chronic pain.

Ankles that are chronically unstable because of lateral ligamentous laxity may benefit from the application of a 0.3-cm lateral heel and sole wedge to prevent inversion. Taping or bracing during vigorous activities is also helpful, as are strengthening exercises. Continuing symptoms may require surgical reconstruction of the lateral ligaments to relieve symptoms of instability, although late traumatic arthritis or chronic instability is rare regardless of treatment.

NOTE: Evidence-based studies suggest the following: (1) there are no significant differences in outcomes between surgical and nonsurgical treatment of acute lateral ligament injuries of the ankle; and (2) ultrasound therapy appears to be of no benefit in the treatment of acute ankle sprains.

Tarsal Tunnel Syndrome

Nerve entrapment rarely may occur in the foot by compression of the posterior tibial nerve beneath the flexor retinaculum at the ankle. This retinaculum arises from the medial malleolus and inserts into the medial aspect of the calcaneus (Fig. 12-18). Space-occupying lesions, local tendinitis, traction injuries, fibrosis secondary to fractures, or deformities of the heel and foot can all compromise the tunnel and cause pressure on the posterior tibial nerve. The disorder is controversial, and there are many unanswered questions regarding its diagnosis and incidence.

Fig. 12-18 The tarsal tunnel. The posterior tibial nerve runs beneath the flexor retinaculum.

Subluxation of Peroneal Tendons

Sudden, forceful dorsiflexion of the foot accompanied by contraction of the peroneal muscles may cause a tear in the retinaculum that holds these tendons in their groove behind the lateral malleolus. This may allow the tendons to acutely or chronically sublux over the lateral malleolus (Fig. 12-19). The condition can also follow a severe lateral ankle sprain.

Fig. 12-19 Subluxing peroneal tendons.

Osteochondritis Dissecans of the Talus (Talar Dome Fracture)

This condition is characterized by the formation of a small area of necrotic bone on the articular surface of the talus. The cause is usually traumatic, and the medial aspect of the talus is the area most commonly involved. It is often the lesion causing persistent symptoms after a “sprain” that does not heal. The necrotic fragment may even become detached from its base, becoming a loose body.

CLINICAL FEATURES

The onset is gradual, and a history of injury may be absent. The disorder usually occurs during adolescence or early adulthood. A painful limp and chronic swelling in the ankle with activity are common complaints. Examination of the ankle with the foot in plantar flexion may reveal an area of point tenderess over the articular surface of the talus. Ankle motion is frequently restricted. Occasionally, if the fragment is detached, intermittent locking may occur, but this is rare because the loose body usually settles into a joint recess and attaches to the soft tissue.

Roentgenographic examination usually reveals the characteristic lesion. MRI and CT are helpful in questionable cases (Fig. 12-20). They are also useful in determining the status of the lesion.

Fig. 12-20 A, Radiographic image and (B and C) CT scans showing osteochondritis dissecans of the talus. The arrow indicates the talar dome fracture.

TREATMENT

The undisplaced fragment is treated by prolonged abstinence from weight bearing until the lesion heals. Cast immobilization is frequently indicated. Persistent symptoms or detachment of the fragment may require surgical intervention.

Disorders of the Hindfoot

PLANTAR FASCIITIS (“PAINFUL HEEL SYNDROME”)

The plantar fascia extends from the calcaneus to the proximal phalanges of each toe and plays an important role in gait. It is a common site of pain that frequently develops near its attachment at the medial tubercle of the calcaneus and along the medial longitudinal arch. The etiology is probably overuse with the development of degeneration and microtears. The role of inflammation is unclear. Both heels are frequently affected. This bilateral involvement may be an early symptom of other inflammatory disorders, such as rheumatoid arthritis, gouty arthritis, or ankylosing spondylitis (when it is often referred to as enthesitis or enthesopathy). Risk factors include tight heel cords (reduced ankle dorsiflexion) and obesity. Men and women are affected equally, and runners are more often affected.

CLINICAL FEATURES

The pain is usually felt directly beneath the calcaneus but may be present in the area of the medial arch. The discomfort is characteristically worse with the first steps in the morning or after periods of prolonged sitting and later in the day after weight-bearing activities. Morning pain usually lessens as the foot “warms up.” Examination reveals local point tenderness in the area of involvement, usually the medial tubercle of the calcaneous. The pain may be aggravated by direct pressure or by maneuvers that place the fascia under a strain, such as dorsiflexing the toes and ankle. Some patients have a tight heel cord.

Roentgenographic findings are usually normal but may reveal a traction spur on the os calcis that is directed distally (Fig. 12-21). The significance of this osteophyte in the etiology of symptoms is unknown. It may be a response to muscle tension and is frequently found in the asymptomatic foot. It is not considered the cause of pain. A stress fracture or other bony disorder may need to be ruled out in some cases (Fig. 12-22).

Fig. 12-21 Roentgenography of the os calcis shows the distally directed traction osteophyte on its inferior aspect (arrow). The patient should be reassured that even though a “spur” may be present, it is not sharp as the name might suggest, but rather it is round and smooth, and the relationship between heel pain and heel spurs has never been established.

Fig. 12-22 Stress fracture of the calcaneus.

TREATMENT

Taping, relief pads, heel cups, cushions, and various orthoses have all been used with only modest success. Over-the-counter pads and cups are as effective as more expensive orthoses. No treatment designed to cushion the heel seems to help, probably because heel strike may not be the cause of the problem. Exercises that stretch the heel cord and plantar fascia may help, but they should not be performed in the acutely painful foot. Only a gentle pulling sensation should be felt. Cold or ice as counterirritants may promote temporary relief. A heel lift or high-heeled shoe may relieve pain in some cases. Oral anti-inflammatory medication is used as necessary. Many patients will benefit from local infiltration of the tender area with a steroid/lidocaine mixture (Fig. 12-23). The injection may be repeated three to four times. (Avoid injecting the superficial tissue, which could cause fat pad necrosis.) Application of a short leg walking cast or removable cast-boot for 6 weeks is often very beneficial. Custom-fitted tension night splints that hold the foot in slight dorsiflexion are used in some resistant cases. Physical therapy is not usually recommended. Extracorporeal shock wave therapy has even been tried, but the results are inconclusive.

Fig. 12-23 Injection site for plantar fasciitis. Injection should be through the sole into the area of maximum tenderness. A 25- or 27-gauge needle should be used and the medication injected slowly as some pain may occur. The total volume should be no greater than 1.5 mL.

The prognosis is usually good, although resolution of symptoms may be slow (up to 1 to 2 years in some cases). Medical treatment is effective in 95%of cases. Rupture of the fascia may occur but probably cures the pain and does not seem to cause any significant loss of function. When conservative treatment fails, release of the plantar fascia at its attachment to the os calcis and excision of the bony prominence are indicated but not before 6 to 12 months of medical management.

PLANTAR FIBROMATOSIS

This disorder is a fibrous tissue proliferation of the plantar fascia similar to Dupuytren’s contracture in the palm. Clinically, the plantar lesion usually involves the medial half of the middle of the plantar fascia but rarely causes a contracture, in contrast to Dupuytren’s disease of the hand. The lesion generally begins as a painless subcutaneous nodule that slowly enlarges and eventually becomes tender (Fig. 12-24). Treatment with a molded orthotic may allow transfer of the weight away from the nodule. Surgery is often indicated when weight bearing becomes painful. Recurrence after excision is common.

Fig. 12-24 Plantar fibroma. Commonly, satellite lesions are present.

BURSITIS

Two bursae are consistently present near the insertion of the Achilles tendon (Fig. 12-25). The superficial bursa may be irritated by the constant rubbing of the counter of the shoe. The retrocalcaneal bursa may be irritated by a prominent posterosuperior angle of the calcaneus (Haglund’s disease). The treatment of both conditions is similar. Relief pads, heat, and elevation of the heel of the shoe with a soft cushion are usually sufficient. Deep bursitis may respond to steroid injection, avoiding the tendon. Occasionally, the bursa and any underlying bony prominence may have to be resected.

Fig. 12-25 Bursae of the heel. S, Superficial calcaneal bursa; R, retrocalcaneal bursa; T, Achilles tendon; P, plantar fascia.

CALCANEAL APOPHYSITIS

A low-grade inflammatory reaction at the insertion of the Achilles tendon is frequently seen in boys between the ages of 8 and 14 years in association with irregular ossification and sclerosis of the calcaneal apophysis (Fig. 12-26). This disorder, sometimes referred to as Sever’s disease, is similar in nature to Osgood–Schlatter disease of the knee. The condition is often bilateral. Local pain, tenderness, and swelling that are aggravated by activity are common. Passive stretching of the heel cord may reproduce the pain.

Fig. 12-26 Roentgenogram of the heel in Sever’s disease. Sclerosis of the apophysis is a normal finding.

Radiographs of the heel may reveal sclerosis of the apophysis, This finding was previously thought to be pathologic, but it is now recognized that it is probably not related to the presence of pain in the heel because these same findings are found in the normal, asymptomatic foot.

Treatment includes NSAIDs, local heat, and the avoidance of activity. A 1.25-cm heel lift may diminish the stress on the heel cord. Stretching exercises may help. A short leg walking cast applied with the foot in slight equinus may be necessary in the rare resistant case. The disease is always self-limited.

ACHILLES TENDON RUPTURE

Spontaneous rupture of the heel cord is a disorder that usually results from gradual degeneration of the tendon. (A normal tendon is very difficult to pull apart.) There is also a greater incidence in patients taking quinolones. The rupture usually occurs 2.5 to 5 cm from the insertion of the tendon into the os calcis. The injury is missed by the initial treating physician up to 25% of the time, probably because bleeding may obscure the clinical findings.

CLINICAL FEATURES

Rupture frequently occurs during an activity that puts stress on the tendon, such as jumping or pushing off with the weight on the forefoot. The acute injury is often associated with a “pop,” and the patient often describes the feeling that the heel was shot or kicked by someone. After the injury, the patient walks flatfooted and is unable to stand on the ball of the foot. Tenderness and hemorrhage are present, and a sulcus is usually palpable at the site of the rupture. However, this sulcus may be obscured by an organizing clot if the examination is delayed (a fact that may explain the difficulty in early diagnosis). Although active plantar flexion is usually lost, some flexion occasionally remains because of the activity of the other posterior compartment muscles. Thompson’s squeeze test is usually abnormal (Fig. 12-27). Excessive passive dorsiflexion of the ankle will also be present and with the feet hanging, the injured side may also rest in more dorsiflexion.

Fig. 12-27 Thompson’s test. The normal foot will automatically plantar flex when the calf is squeezed (A). This movement is absent when the heel cord is ruptured (B).

TREATMENT

Referral is indicated as soon as the diagnosis is made. Delay in treatment more than a week could compromise the outcome. The best results of treatment are obtained by immediate surgical repair. Nonoperative treatment by applying a short leg cast with the foot in equinus also allows healing in many cases. Recurrence of the rupture is not uncommon regardless of treatment, and protection from excessive activity must be maintained for up to 1 year. Competitive athletes are often unable to perform as well as before the injury. Neglected ruptures usually require reconstruction.

Incomplete or partial rupture may present with tender swelling in the same area that complete rupture occurs. MRI is useful in confirming the diagnosis. Treatment is by protection until healing has occurred followed by careful rehabilitation.

Disorders of the Forefoot

MORTON’S NEUROMA

A common cause of pain in the forefoot is the interdigital neuroma. This lesion results from perineural fibrosis of the plantar nerve where the medial and lateral plantar branches communicate (Fig. 12-28). It may represent an entrapment neuropathy similar to carpal tunnel syndrome. The condition is probably secondary to repetitive trauma, and the fibrosis results in a painful fusiform swelling of the nerve. Females are more commonly affected. Tight shoe wear may be a cause.

Fig. 12-28 Morton’s neuroma.

CLINICAL FEATURES

The clinical picture is one of severe burning pain, accentuated by activity, most often in the region of the third web space (rarely, the second). The pain may radiate into the third and fourth toes. Tight shoes aggravate the discomfort, and the pain is often relieved by removing the shoe and massaging the foot. Numbness may be present in the affected toes.

The examination is usually unremarkable, except for exquisite tenderness on digital pressure between the third and fourth metatarsal heads. Compression of the forefoot transversely may also reproduce the pain. Sometimes, while applying compression, a “click” may be felt in the web when bursa or neuroma is caught between the metatarsal heads. Some decrease in sensation may be present on the opposing surfaces of the two affected toes. Roentgen and electrical studies are not helpful. The diagnosis is usually clinical.

TREATMENT

A pad that separates the heads of the third and fourth metatarsals may be helpful. NSAIDs may be tried, and a local injection of a steroid/lidocaine mixture into the tender web area from a dorsal approach may give some relief (Fig. 12-29). The patient should avoid tight-fitting shoes. Surgical removal of the neuroma is often necessary.

Fig. 12-29 Third web space injection for Morton’s neuroma. For injection, 1 mL of steroid mixed with 2 mL of lidocaine is used.

Hallux Valgus

Hallux valgus is a lateral deviation of the great toe at the MTP joint. This is usually associated with bony and soft tissue enlargement over the medial aspect of the first metatarsal head that is referred to as the bunion. Females are affected 10 times as often as males. The cause is unknown, but heredity and the wearing of tight shoes play major roles.

CLINICAL FEATURES

Pain and deformity are the main initial symptoms. The soft tissue over the prominence may become inflamed and tender. Sometimes the bunion bump even ulcerates and drains. Painful calluses frequently develop on the second toe, which is forced into hyperextension by the deviated great toe.

Roentgenographic findings include lateral displacement of the proximal phalanx and the presence of a medial exostosis (Fig. 12-33). Degenerative changes may also be present in the MTP joint.

Fig. 12-33 Hallux valgus with bunion exostosis.

Hallux Rigidus

Hallux rigidus is a painful condition affecting the MTP joint of the great toe and is characterized by restriction of motion. It is usually secondary to traumatic osteoarthritis. The condition may develop at any age but is most common in the third and fourth decades. Because it affects the MTP joint of the great toe, it is sometimes confused with gout.

CLINICAL FEATURES

Gradually increasing pain and stiffness are typical. They are often precipitated by a minor injury. The pain occurs with ambulation, especially when the patient’s toe is dorsiflexed late in the stance phase of walking. The patient may compensate by shifting the weight onto the lateral border of the foot. Examination reveals swelling, tenderness, and restricted motion of the MTP joint. Attempts at passive motion, especially dorsiflexion, are painful. Osteophytic buildup is easily palpable on the dorsum of the joint. The toe is held in a protective position of slight flexion, and as the patient walks, more weight is borne on the outer metatarsal heads and lateral border because of the lack of ability to extend the great toe.

The roentgenogram usually reveals typical findings of degenerative arthritis with joint narrowing and spur formation (Fig. 12-34).

Fig. 12-34 Hallux rigidus. Narrowing and sclerosis are present at the MTP joint of the great toe.

TREATMENT

Symptomatic relief can be obtained by rest, moist heat, and anti-inflammatory medication. An intraarticular injection of steroid may provide additional relief (Fig. 12-35). A shoe with sufficient room in the forefoot is worn, and an anterior metatarsal bar is applied to the shoe. A rockerbottom shoe may also be tried. It allows the foot to roll over without dorsiflexion of the toes, but it is awkward in appearance. Arthroplasty or arthrodesis of the MTP joint is indicated in resistant cases.

Fig. 12-35 Injecting the MTP joint of the great toe. Palpate the joint line, and apply distal traction to distract the space. A 25-gauge needle is used from a dorsal approach, and 1 to 2 mL of fluid is injected.

Hallux Varus

Hallux varus is a deformity, usually seen in children, in which medial angulation of the great toe occurs at the MTP joint. It is usually congenital and associated with other foot deformities, but it may be seen in adults following surgical overcorrection of a hallux valgus deformity. Mild cases in children may respond to passive stretching exercises and proper shoe wear. More severe cases in both adults and children usually require surgical correction.

Congenital Overlapping Fifth Toe

This is a common familial deformity, frequently bilateral, in which the small toe is dorsiflexed and may come to lie on the top of the fourth toe (Fig. 12-36). The capsule and extensor tendon on the dorsum of the metatarsophalangeal joint are shortened and do not allow passive correction of the deformity. Calluses may develop on the dorsum of the toe secondary to chronic irritation by the shoe. Passive stretching of mild deformities is indicated but usually does not completely correct the problem. Surgical realignment or even amputation may be necessary in symptomatic cases.

Fig. 12-36 Congenital overlapping fifth toe.

Hammertoe

A hammertoe is one in which a flexion deformity develops at the proximal interphalangeal joint and causes the tip of the toe to be depressed downward (Fig. 12-37). A mild hyperextension deformity at the MTP joint may be present. Painful calluses develop over the tip of the toe, over the dorsum of the proximal interphalangeal joint, and under the metatarsal heads. The second toe is most commonly affected, and the disorder is frequently seen in association with a hallux valgus deformity of the great toe. The cause is often improperly fitted, tight shoes that crowd the toes.

Fig. 12-37 Hammered second toe with a dorsal callus. Also shown are the soft corn (S), bunionette (B), and hard corn (H).

Mild flexible deformities may be corrected by stretching exercises and “over-and-under” taping to adjacent toes (Fig. 12-38). Toe caps or pads may also be helpful. Properly fitted or shoes are a must. Extra-depth shoes may be needed. Resistant cases usually require surgical correction.

Fig. 12-38 Over-and-under taping for a hammered or clawed second toe. The second toe is most often clawed, frequently because it is too long. Before taping, stretching exercises are performed to improve the MTP extension and IP flexion contractures. The tape is applied to the proximal phalanx in most cases, holding the MTP joint in neutral position.

Corns and Calluses

Corns and calluses develop in response to abnormal pressures against the skin of the foot. External pressure from poorly fitted shoes combined with internal pressure from abnormal bony protuberances frequently leads to the production of thickened, painful, hard skin over the bony prominence. In areas where moisture and perspiration collect, the skin becomes macerated, and a soft corn (clavus mollis) develops that may even ulcerate.

Hard corns (clavus durus) are most commonly found on the dorsolateral aspect of the proximal interphalangeal joint of the fifth toe, whereas soft corns are most common in the fourth web space. The tailor’s bunion or bunionette occurs on the dorsolateral aspect of the MTP joint of the fifth toe. Calluses are common under the weight-bearing portion of the metatarsal heads or sesamoid bones of the great toe.

Removal of the external pressure is essential in the conservative management of all of these soft tissue lesions in the forefoot. A low-heeled shoe with adequate width in the forefoot is recommended. Donut relief pads and metatarsal bars are usually helpful. Warm soaks in soapy water followed by the application of a keratolytic medication, such as salicylic acid salve, will help eliminate the callus or corn. The normal skin should be avoided when applying the salve. The salve should remain in place for 3 to 5 days and be covered by adhesive tape. The patient should watch for skin maceration. After the tape is removed, the hard callus or corn may be shaved in layers. After warm soaks, a pumice stone may also be used to pare down the callus. This procedure is frequently helpful, but deep excision of any corn or callus should be avoided because an infected ulcer may result. Soft corns may be eliminated in 1 to 2 weeks, but hard calluses may take longer. A cotton pad or lamb’s wool may be placed between the toes if a soft corn is present, and a doughnut-shaped pad is always worn around a hard corn or callus to shift weight from the lesion to the adjacent normal skin. The toes should be kept as dry as possible at all times.

Surgical correction may be advised in resistant cases to eliminate the bony prominence.

Plantar warts also occur near the metatarsal heads but usually not directly on the weight-bearing surface. The wart is generally surrounded by a callus and may look exactly like a simple callus. Characteristic papillary tips are usually present. Paring or curettage of the wart and the use of a keratolytic agent such as salicylic acid salve frequently effects a cure. Relief pads are worn as necessary. The lesion has a high incidence of spontaneous disappearance in several months.

Disorders of the Toenail

A common condition that affects mainly the great toe is the ingrown nail. In this disorder, the nail does not actually grow into the soft tissue, but instead, the soft tissue overgrows and obliterates the nail sulcus (Fig. 12-39). The nail itself is usually normal, although some older patients have incurved nails. The causes are probably multiple, but incorrect nail trimming, cleaning the nail gutters with sharp tools that penetrate the skin, improperly fitted tight shoes and stockings, and bony deformities have all been implicated. A simple break in the skin can create a portal of entry for bacteria. Because of improper trimming, a small nail spike may even be formed that continues to grow and irritate the soft tissue (Fig. 12-40). A chronic infection is usually the end result. Unusual bony lesions such as subungual exostosis should be ruled out with routine radiographs.

Fig. 12-39 A typical ingrown great toenail.

Fig. 12-40 The ingrown toenail frequently results from improper trimming that produces a nail spike. The nail should always be trimmed transversely.

In most mild early cases, soaks, antibiotics, and proper shoes and stockings may be curative. The nail edge should be kept elevated with a soft cotton wad or metal shield until it grows out beyond the soft tissue reaction. Unfortunately, this can be a slow process, because the nail takes approximately 3 months to grow 1 cm. Patience is required. Proper transverse trimming of the nail should prevent recurrences.

Surgery may be necessary in resistant cases. Among the procedures used, removal of the central portion of the nail does not seem to allow the lateral margin of the nail to elevate away from the sulcus as theorized. Avulsing the whole nail is usually not effective either. When the nail regrows, it usually runs into the soft tissues again and causes the common recurrence in up to 70% of cases. The surgical procedures most commonly used involve removing (1) one or both nail margins, (2) the entire nail, or (3) the entire nail plus a tuft of the distal phalanx. Removing one or both nail margins is the most popular procedure. Removing the whole nail sometimes leaves an unsightly nail plate area, and amputating the distal tuft causes some shortening. Soft tissue procedures are rarely used because of a high recurrence rate.

Surgery for nail margin removal is as follows (Fig. 12-41):

Fig. 12-41 Ingrown toenail removal. A, A short, angled skin incision is made in the eponychium down to the nail. B, With heavy scissors, the portion of the nail to be excised (dotted line) is separated from the remaining nail. (The important area of soft tissue and nail growth matrix to be removed is crosshatched.) C, A curet is used to remove any granulation tissue and remaining soft tissue in the periosteal area of the phalanx, and the incision is closed. A small pack is left in the gutter. D, Approximate cross section of a toe showing the area to be removed under the skin. It is not necessary to remove tissue very far beyond the lunula, but be certain to remove all necessary growth matrix to prevent any spikes of nail from regrowing at the margin. (NOTE: The nail grows from a dorsal and deep matrix that envelops the base of the nail and extends just beyond the lunula. This area also extends proximally beneath the eponychium.) Both sides may be done if necessary. The “articulation” between the two is often confused with a fracture line.

Phenol cauterization and sodium hydroxide have also been used to eliminate the germinal matrix itself. The results are about the same as those obtained with surgical removal.

Surgery for an older, thickened incurved nail usually involves removing the entire nail because, as a rule, the whole nail is involved.

Two other common conditions, the hypertrophied nail and the ram’s-horn nail, may result from poor local hygiene. Both are most common in the elderly. A hypertrophied nail is usually caused by a low-grade fungus infection (onychomycosis). The affected nail is thickened, and a yellow, powdery substance is present beneath it. A ram’s-horn nail is characterized by massive overgrowth. The nail may even curl over to the plantar aspect of the toe. The ram’s-horn nail may respond to soaks and careful pedicures with paring and filing the nail to decrease volume. Removal of the entire nail is occasionally required.

Accessory Bones

Many accessory and sesamoid bones are present in the normal foot (Fig. 12-42). They are occasionally confused with fractures. Most are asymptomatic. However, an unusually large accessory navicular bone may cause pain from local pressure where the prominence protrudes against the shoe (Fig. 12-43). It is usually bilateral and is frequently associated with weakness in the longitudinal arch and a mild flatfoot deformity. Relief pads or shoe modifications may eliminate symptoms, but surgical excision of the bony prominence is sometimes necessary to completely relieve the pain.

Fig. 12-42 Accessory and sesamoid bones of the foot.

Fig. 12-43 Accessory navicular. The medial navicular is also enlarged.

Fractures of the Ankle

The ankle joint or “mortise” is an inverted U with the dome of the talus fitting between the medial and lateral malleoli. The posterior margin of the tibia is often called the third or posterior malleolus.

The talus is held in its position by bony and ligamentous structures and occupies a special position in the ankle joint. Any deviation from that position through injury could result in traumatic arthritis.

Most common ankle fractures are the result of eversion or lateral rotation forces on the talus (in contrast to common sprains, which are usually caused by inversion).

PHYSICAL FINDINGS

The amount of deformity usually depends on the extent of displacement. Pain, tenderness, and hemorrhage are usually present at the site of the injury. The ligamentous structures (especially the deltoid ligament) should be gently palpated to determine the extent of any associated soft tissue injury.

IMAGING STUDIES

Accurate roentgenographic assessment of ankle injuries requires standard anteroposterior and lateral views accompanied by an anteroposterior view taken 15 degrees internally rotated. The last view is taken to properly visualize the mortise.

TREATMENT

The two most important clinical and roentgenographic assessments that determine the treatment of ankle fractures are: (1) the position of the talus in the mortise and (2) the stability of the fracture. If the talus is already displaced, referral is indicated because reduction is required, sometimes by surgical means, to restore the ankle mortise (Fig. 12-44). Any deviation of the position of the talus in the joint could lead to traumatic arthritis.

Fig. 12-44 Fracture of the lateral malleolus with widening of the ankle mortise (arrow), sometimes called the medial clear space (MCS). Healing in this position could lead to traumatic arthritis.

If there is no widening of the ankle mortise (talar displacement), many injuries can safely be treated with simple casting without reduction or surgical intervention. There is, however, the potential for displacement if both sides of the joint are significantly injured (for example, the common oblique fracture of the lateral malleolus with rupture of the deltoid ligament on the medial side). It is important to determine by clinical examination (tenderness) if ligamentous injury might be present in addition to the fracture. If that is the case, the injury can still be treated with casting, but it is considered unstable and weight bearing is prohibited to prevent displacement in the cast. All ankle fractures should be routinely evaluated roentgenographically at 1 to 2 weeks to determine any sign of displacement of the talus. Some of the more common ankle fractures and their treatment are as follows:

1 Undisplaced or avulsion fractures of either malleolus below the ankle joint line. Stability of the joint is not compromised, and a short leg walking cast or walking cast boot would be sufficient (Fig. 12-45). Weight bearing is allowed as tolerated. Protection may be discontinued within 4 to 6 weeks.

2 Isolated undisplaced fractures of the medial, lateral, or posterior malleolus without ligamentous injury are usually stable and require only a short leg walking cast or fracture boot for 8 weeks. The fracture line of the lateral malleolus may persist roentgenographically for several months, but immobilization beyond 8 weeks is unnecessary. Undisplaced bimalleolar fractures are treated with a long leg cast flexed 30 degrees at the knee to prevent displacement of the fracture fragments. In 4 weeks, a short leg walking cast may be applied for an additional 4 weeks.

3 Isolated fractures of the lateral malleolus that are slightly displaced may be treated with casting if no medial (deltoid) ligament injury is present (Fig. 12-46). A cast boot or below-knee walking cast is applied with the ankle in neutral position, and weight bearing is allowed as tolerated. Immobilization for 8 weeks is sufficient, and radiographs are repeated at 2 weeks. If medial tenderness is present, suggesting deltoid ligament rupture, a carefully molded cast should suffice if weight bearing is not allowed, and the patient is followed closely with repeat radiographs to be certain that further displacement has not occurred, especially after swelling recedes. If any significant widening of the medial ankle mortise develops as a result of lateral displacement of the talus (increase in the “medial clear space”), referral is appropriate.

4 The undisplaced fracture of the distal fibular growth plate is diagnosed clinically. There is tenderness over the epiphyseal plate. Roentgenographic examination is usually negative. A short leg walking cast or fracture cast boot for 4 weeks is sufficient. Growth disturbance is rare.

5 Isolated displaced fractures of the posterior malleolus involving less than 25% of the articular surface can safely be treated with a fracture cast boot or short leg cast (Fig. 12-47). Patients with fractures involving greater than 25% should be referred.

6 Isolated, displaced fractures of the medial malleolus may require open reduction, and patients with these injuries should be referred (Fig. 12-48).

Fig. 12-45 The fracture “cast boot.” This device can be used for a variety of conditions, including chronic tendinitis, painful ankle sprains, and many ankle fractures. A model is available with a hinge (arrow) that allows the position to be adjusted if that is preferable (such as placing the ankle in slight plantarflexion in cases of Achilles tendinitis). Models that are not adjustable are fixed in the neutral position of 90 degrees. These are less expensive and are suitable for the majority of soft tissue and bony injuries involving the foot and ankle.

Fig. 12-46 Minimally displaced fracture of the lateral malleolus (arrow) with no widening of the ankle mortise.

Fig. 12-47 Minimally displaced fracture of the posterior malleolus (arrow).

Fig. 12-48 Fracture of the medial malleolus indicated by arrows.

Fractures with dislocation of the talus should be reduced as rapidly as possible (Fig. 12-49). If the dislocation is not promptly reduced, severe soft tissue injury with blistering and skin breakdown may result. Definitive surgical treatment of the fractures may also have to be delayed. The dislocation is reduced by traction and manipulation with the patient under local anesthesia. After reduction, the ankle is placed in a soft “Jones” bulky compression dressing reinforced with plaster splints. Any necessary surgery can then be performed on an elective basis.

Fig. 12-49 Fracture-dislocation of the ankle.

Fractures of the Foot

FRACTURES OF THE CALCANEUS

Fracture of the calcaneus usually results from a fall on the heel; 10% of such injuries are associated with a compression fracture of the lumbar spine. (The heel is usually so painful that the back pain may not be noticed until much later.) The os calcis is usually crushed, and the fragments are displaced in varying amounts (Fig. 12-50).

Fig. 12-50 Fracture of the calcaneus (arrows) with moderate displacement.

Fractures of the os calcis are painful injuries characterized by severe swelling. The swelling may be so intense that blistering and even skin necrosis may occur. To control the swelling and hemorrhage, all calcaneus fractures are treated initially with a bulky, soft compression dressing, ice, and elevation. A cast is never applied immediately after the injury. The pain from the fracture and swelling is only intensified if a constricting circular cast is present over the heel.

Minimally displaced fractures are treated by cast immobilization for 2 to 3 weeks or with crutches and the avoidance of bearing weight. The cast is removed as soon as possible to begin mobilization of the ankle and heel. Eversion and inversion movements are begun, but weight bearing is not allowed for 6 to 8 weeks until the fracture has healed. Displaced fractures may be treated in the same manner or by either closed or open reduction.

Regardless of treatment, prolonged immobilization is inadvisable. Temporary disability after this injury may persist for 1 to 2 years, and some permanent impairment is common. Early motion without weight bearing appears to be most beneficial. Some restriction of eversion and inversion is usually permanent, which makes walking on rough, irregular surfaces difficult. The heel is often widened permanently. Late surgery is often helpful if symptoms persist.

FRACTURES OF THE TALUS

Fractures of the talus are not common, other than talar dome injuries as previously discussed. Subtle fractures of the anterior and posterior talar processes that occur in conjunction with sprains may be missed. These injuries should always be considered whenever an ankle “sprain” does not recover within the expected time frame. Repeat radiographic evaluation should be performed, including CT or MRI in difficult cases.

Fractures of the neck of the talus can be more problematic (Fig. 12-51). Outcomes depend greatly on the amount of initial displacement. Undisplaced fractures have a favorable prognosis in most instances. Displacement carries a worse prognosis. Osteonecrosis, malunion, and nonunion are common complications, and operative treatment is often required to prevent them.

Fig. 12-51 Fracture of the neck of the talus (arrows).

FRACTURES OF THE METATARSALS

Fractures of the necks or shafts of the metatarsals usually result from compression injuries of the foot. Undisplaced fractures require little treatment other than a soft compression dressing and crutches for 4 to 6 weeks. A short leg walking cast, fracture boot, or hard-soled sandal may be preferable in a few days to allow the patient to discard the crutches.

Displaced fractures of the necks of the metatarsals may need reduction to prevent pain from developing under the metatarsal heads (Fig. 12-52). Manipulation is sometimes effective, but maintenance of the reduction is frequently difficult. Open reduction with internal fixation is sometimes necessary.

Fig. 12-52 Displaced fractures of the metatarsals.

Fractures of the base or styloid of the fifth metatarsal are common and result from an inversion injury to the foot (Fig. 12-53). They are usually undisplaced and require little treatment. A light compression dressing and hard-soled sandal are usually sufficient. Crutches may be necessary for 7 to 10 days, and healing is usually complete in 5 to 6 weeks. Nonunion is unusual, and even when it occurs it is rarely symptomatic.

Fig. 12-53 Fracture of the base of the fifth metatarsal.

Fractures of the shaft of the fifth metatarsal, especially proximal ones, heal slowly and may require a short leg walking cast for 6 to 8 weeks (Fig. 12-54). The cortex of the proximal diaphysis is normally thick and often relatively avascular, especially in long-distance runners, due to high stresses. The relatively poor circulation in this area may lead to delayed union and even nonunion. Surgical intervention may even be required.

Fig. 12-54 Fracture of the proximal shaft of the fifth metatarsal.

LISFRANC’S INJURY

The tarsometatarsal joint complex is often called Lisfranc’s joint. Injuries to this part of the foot may range from simple undisplaced joint fractures to more severe fracture-dislocations involving all of the tarsometatarsal articulations. Many of these injuries are missed.

The key articulation of the midfoot is the second TMT joint, which helps to stabilize the other joints. Here, the middle cuneiform is recessed from the first and third, creating a “mortise” into which fits the base of the second metatarsal.

The mechanism of injury is often a partially missed step. Physical signs include tenderness and swelling in the affected area. This pain can be reproduced by stabilizing the heel with one hand and twisting the forefoot with the other.

Radiographic findings in subtle injuries may be missed. An important key is the alignment of the second metatarsal with the middle cuneiform. A line drawn along the medial aspect of the metatarsal should be continuous with a line along the medial aspect of the cuneiform. Comparison views with the normal foot may be needed. A shift of the base of the second metatarsal may be noted, and a small avulsion fracture, sometimes called a fleck sign or Lisfranc’s fragment, may be seen (Fig. 12-55).

Fig. 12-55 Lisfranc injury showing the “fleck” sign (arrow).

Undisplaced fractures are treated with immobilization, but if there is any indication of displacement, orthopedic referral is needed to determine whether surgery may be indicated to avoid the late complication of posttraumatic arthritis.

FRACTURES OF THE PHALANGES

Fractures of the toes are common and usually require little treatment. Undisplaced fractures may be treated by taping the injured toe to the adjacent toe for 3 to 4 weeks (Fig. 12-56). Displaced fractures can usually be reduced without anesthesia. Open reduction is rarely necessary. However, fractures of the proximal phalanx of the great toe should be reduced accurately.

Fig. 12-56 “Buddy” taping of the toes. Gauze between the toes may help prevent skin maceration.

Foot Care

Most foot problems develop in the forefoot, and many have been previously discussed. For the treatment of painful conditions of the forefoot, the patient should avoid wearing high heels and keep the foot in a soft shoe with a wide toe box (the portion covering the forefoot). The simple addition of an anterior heel (anterior metatarsal bar) will improve many of the problems that develop under the metatarsal heads. The diabetic patient with or without vascular disease has the potential for far more serious problems, and special care must be taken to avoid them. The following general principles are helpful:

When ulcers do develop, they are most common on the weight-bearing surface of the foot or on the medial aspect of the great toe. These are often referred to as mal-perforans (Fig. 12-57). At this stage, vigorous local care, minor debridement, and control of infection are indicated. Excessive heat, which places a great demand on the soft tissue, should be avoided. The previously mentioned metatarsal bars and insoles are used to relieve the pressure on the ulcer. If the foot is warm and has pulses, amputation is usually not necessary, and healing of these ulcers commonly occurs with proper care.

Fig. 12-57 Healing mal-perforans ulcer of the great toe.