Common foot problems

A. Achilles tendinitis is a common condition of the Achilles tendon that presents with pain either at or just proximal to its insertion into the calcaneal tuberosity. It is frequently caused by overuse related to athletic participation. Degenerative changes within the tendon itself may be the cause in older persons. Occasionally, inflammatory disorders such as gout or Reiter's syndrome may precipitate such a condition.

1. Physical examination. The tendon itself may be thickened approximately 2 to 3 cm proximal to the insertion. Local tenderness is frequently present. A palpable bony prominence may be noted at the calcaneal insertion. An overlying adventitial bursa may be present as well. Active ankle plantar flexion may reveal subtle weakness in comparison with the contralateral extremity. The Thompson test (squeezing the calf) causes ankle plantar flexion, thereby ruling out a rupture of the tendon.

2. Radiography may demonstrate a soft-tissue thickening at the level of the tendinopathy. Alternatively, a degenerative spur may be seen "growing" up into the tendon at its insertion.

3. The treatment of an acute tendinitis revolves around reducing the associated inflammation. A brief period of rest in a walking boot or cast may result in significant resolution of symptoms. Antiinflammatory medications, judicious use of cryotherapy, and gentle physiotherapy on the resumption of athletic activity are valuable adjuncts. Steroid injection can lead to tendon rupture. Particular attention should be paid to gastrocnemius equinus contracture, which is frequently present in recalcitrant cases. Chronic tendinitis unresponsive to conservative measures frequently will benefit from surgical debridement of the diseased tendon with excision of a bony spur, if present. Should considerable weakness exist in the degenerative condition or if insufficient tendon remains after debridement, augmentation with the flexor hallucis longus tendon is particularly useful.

B. Plantar heel pain is one of the most common disorders seen by physicians who manage foot and ankle problems. Plantar fasciitis, an irritation of the plantar fascia at its origin on the posteromedial tubercle of the calcaneus, is the most common cause of plantar heel pain. Atrophy of the normal plantar fat pad may result in difficulty walking because of plantar heel pain. Entrapment of branches of the posterior tibial nerve as they cross in close proximity to the heel may also result in plantar heel pain. Inflammatory arthropathies (psoriatic arthritis and Reiter's syndrome » RA) frequently present with plantar heel pain, often before the systemic nature of these diseases is appreciated.

1. Physical examination may reveal tenderness at the origin of the plantar fascia. Dorsiflexion of the MTP joints may exacerbate the tenderness because this stretches the fascia. "Start-up" pain during the first step in the morning or after prolonged sitting is common. Gastrocnemius equinus contracture (continuous with the plantar fascia) is frequently present.

2. Radiographic findings are frequently normal. An incidental traction spur at the origin of the flexor digitorum brevis muscle may be present. This is rarely, however, the source of the discomfort.

3. Treatment should be directed at unloading the heel with soft cushioning in the shoe, vigorous stretching of the plantar fascia-gastrocnemius complex, and administering nonsteroidal antiinflammatory medications. Occasional night splinting is helpful in the persistent case. Patients should be counseled about the often-prolonged nature of the disorder. In more than 95% of cases, symptoms will resolve within 12 months. In the presence of significant tendoachilles or gastrocnemius contracture, tendon release and lengthening are often curative.

C. Pes planus deformity and posterior tibial tendon insufficiency have received considerable attention recently. A flat foot, in and of itself, is not pathologic. However, when associated with progressive pain and deformity, it warrants intervention. Static factors contributing to the integrity of the medial longitudinal arch include the plantar fascia, the spring ligament, and the capsular and ligamentous structures associated with the bones of the medial column of the foot. The dynamic factor most commonly associated with the maintenance of the medial arch is the posterior tibial muscle and its tendon. When overloaded (e.g., by a gastrocnemius equinus contracture), the posterior tibial tendon fails. The hindfoot remains in valgus. Eventually, the static supports of the longitudinal arch fail and a sag is noted in the midfoot. The foot assumes a pronated posture and exacerbates the hindfoot valgus, which increases the gastrocnemius contracture. Eventually, degenerative changes occur in the midfoot and hindfoot joints if the problem is left untreated.

1. Physical examination demonstrates a complex deformity with varying degrees of hindfoot valgus and midfoot pronation and abduction. Early on in the disorder, tenderness is noted along the posterior tibial tendon below the medial malleolus. However, in the advanced case, pain along the posterolateral hindfoot predominates because of calcaneofibular impingement. The "too many toes" sign may be viewed from behind with excessive hindfoot valgus. The inability to perform a single-limb heel-rise or invert the heel may be noted. Claw toes and a hallux valgus deformity may develop secondarily.

2. Radiography should always be performed during weight bearing. The lateral radiograph will often demonstrate a sag in the longitudinal arch of the foot and an increase in the talocalcaneal angle. The anteroposterior radiograph will similarly demonstrate an increase in the talocalcaneal angle as well as loss of coverage of the talar head by the navicular. In long-standing cases, degenerative arthrosis may be noted in the hindfoot, particularly the subtalar joint.

3. Treatment depends on the stage of the disease.

a. Stage 1 disease, marked by posterior tibial tendinitis (without deformity), is treated by immobilization of the foot to allow the posterior tibial tendinitis to resolve, followed by use of a supportive insole orthosis. Lengthening of a contracted tendoachilles complex, when present, is particularly helpful in arresting progression.

b. Stage 2 disease, marked by tendon insufficiency and flexible pes planus deformity, is best treated surgically with tendoachilles lengthening, posterior tibial tendon augmentation, and medial column stabilization via arthrodesis of the nonessential joints of the midfoot.

c. Stage 3 disease is characterized by either fixed pes planus deformity or degenerative arthrodesis of one or more of the essential hindfoot joints (i.e., the subtalar joint). However, the significant limitation of normal gait mechanics that results warrants early, aggressive intervention when the deformity is flexible and hindfoot arthrodesis can be avoided.

D. Metatarsalgia represents a condition characterized by pain under the weight-bearing surfaces of the metatarsal heads. Its many causes include hypermobility of the first ray with compensatory overload of the lesser metatarsals, claw toes (in which the plantar fat pad is drawn distally to expose the plantar metatarsal heads), and a rigid cavovarus foot and tendoachilles-gastrocnemius equinus contracture. It may be prominent in RA.

1. On palpation of the plantar forefoot, prominence of the metatarsal heads may be noted. The plantar metatarsal fat pad may be displaced distally in the presence of hammer toe or claw toe deformities. A hypermobile first ray with overload of the lesser toes will present with plantar keratoses beneath the second (and third) metatarsal heads. Gastrocnemius equinus contracture and claw toes routinely coexist in this syndrome.

2. Radiography. Claw toe deformities may be demonstrated on weight-bearing lateral radiographs. A forefoot cavus posture may be evident as well. The anteroposterior radiograph will demonstrate a long, hypertrophied second metatarsal in the hypermobile first-ray syndrome.

3. Treatment is directed at unloading the excessive plantar pressure beneath the metatarsal heads. Various nonoperative measures that are particularly helpful include placing a metatarsal pad just proximal to the metatarsal heads. Accommodative inserts can also provide unloading of the metatarsal heads. Surgical correction of lesser claw toe deformities can replace the plantar fat pad beneath the metatarsal heads. Stabilization of the hypermobile first ray can redistribute plantar weight-bearing forces. Gastrocnemius equinus contracture can be relieved through tendoachilles or gastrocnemius tendon lengthening.

E. (Morton's) neuroma is the presence of pain in the web space between the third and fourth toes caused by irritation of the common plantar interdigital nerve at this location. Many etiologies are thought to contribute to this disorder, including constrictive shoes with a narrow toe box, forefoot overload with metatarsalgia, and gastrocnemius equinus contracture. Patients typically complain of a numbness or burning sensation radiating into the toes that is promptly relieved by removing the shoes and rubbing the feet.

1. Symptoms may be reproduced during compression of the metatarsal heads by the examiner. A palpable mass may be appreciated in the appropriate web space.

2. Radiographic findings are routinely normal. MRI can be helpful when the diagnosis is uncertain.

3. Treatment includes wearing appropriate shoes to accommodate the natural width of the forefoot. A metatarsal pad may serve to splay the metatarsal heads and provide symptom relief. In recalcitrant cases, local steroid injection or surgical excision is warranted.

F. Inversion ankle injuries (sprains) are among the most common musculoskeletal injuries seen by the physician. Recall that the talus is wider anteriorly than posteriorly, which renders it particularly susceptible to inversion injury in the plantar-flexed position. Approximately 20% of ankle sprains will progress to varying degrees of chronic ankle instability.

1. Physical examination shortly following an inversion ankle injury reveals swelling located over the anterolateral aspect of the ankle joint. Ecchymoses may be present. Tenderness over the anterior talofibular ligament will be noted on palpation. Involuntary guarding and apprehension to attempted inversion maneuvers will be evident. Depending on the severity of the injury, weight-bearing may not be possible. Additional findings on the medial portion of the ankle indicate a higher-energy injury. Manual stress testing with anterior drawer and talar tilt maneuvers, if tolerated, may reveal asymmetry in comparison with the uninjured extremity.

2. Radiographs should always be obtained to rule out a fracture of the fibula or medial malleolus. Small avulsion fractures of the distal fibula are frequently seen and require no specific treatment. As mentioned previously, anteroposterior and lateral stress radiographs comparing the injured and uninjured extremities may prove helpful in subtle cases.

3. Treatment initially is largely supportive. Immobilization, elevation, cryotherapy, and nonsteroidal antiinflammatory medications are instituted until the patient is comfortable. Organized physical therapy to restore normal muscle strength and proprioception is essential for a good outcome. Weight-bearing in a light-weight orthosis that controls inversion and eversion is particularly helpful. Normal activities can gradually be resumed when strength in the injured ankle is equal to that in the uninjured extremity. Chronic ankle instability is most often associated with premature return to athletic activities and early reinjury. Long-term use of a protective orthosis may provide symptomatic relief to those with chronic ankle instability. Surgical repair or reconstruction of elongated lateral ankle ligaments is helpful in those cases in which nonoperative therapy has failed.

G. Hallux valgus is a common condition whose cause is likely multifactorial. Tight and constrictive shoes, ligamentous laxity with muscle imbalance, and hereditary predisposition all contribute to a lateral deviation of the hallux on the first metatarsal. Hallux valgus may often be a part of a larger deformity—namely, the planovalgus foot with a pronated midfoot that gradually stretches the medial capsule of the hallux MTP joint into valgus.

1. Physical examination reveals a lateral deviation of the hallux phalanges, often with impingement of the lesser toes that causes an overlapping second-toe deformity (claw toes). Prominence of the medial aspect of the hallux metatarsal head may cause local paresthesias or ulceration of the overlying soft tissues. Bursal swelling can occur and can become infected. Gastrocnemius equinus contracture and a hypermobile first ray may often be present.

2. Radiography will demonstrate an increased hallux valgus angle and an increased intermetatarsal angle (metatarsus primus varus). Second metatarsal overload may be present. Lateral radiographs may reveal claw toe deformities of the lesser toes. Loss of medial column height (sag) may be noted as well.

3. Treatment should be based on the severity of the deformity and degree of functional limitation and should be directed at the cause of the deformity. Nonoperative measures include accommodative shoes with a wide toe box and insole orthoses to support a flexible pes planus deformity associated with hallux valgus. Operative intervention, when nonoperative measures are not successful, should be directed at the restoration of soft-tissue and osseous stability. Operative intervention is largely successful in appropriately selected patients.

H. Hallux rigidus is a painful condition characterized by a limitation of hallux dorsiflexion. It often coincides with degenerative arthrosis to varying degrees. Remote injuries to the hallux MTP joint may be recalled. Alternatively, an elevated first ray causes the hallux proximal phalanx to "jam" into the first metatarsal head rather than "glide" over it in a smooth arc.

1. Physical examination reveals restricted dorsiflexion at the hallux MTP joint. Prominent osteophytes may be readily palpable, especially over the dorsolateral aspect of the joint.

2. Radiography may reveal varying degrees of osteoarthrosis, from osteophyte formation to joint space narrowing. An elevated first ray may be noted on the lateral radiograph.

3. Treatment in which a steel rocker bar is used in the sole of a shoe to relieve motion at the MTP joint can be quite effective. Surgical intervention, including cheilectomy, is of limited short-term value. In intractable cases, arthrodesis of the MTP joint can be quite helpful.

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