Metatarsalgia

Metatarsalgia is a general term for pain in the area of the metatarsophalangeal joints (ball of the foot). Most common causes include interdigital neuralgia (often due to Morton's neuroma), metatarsophalangeal joint pain, and sesamoiditis.

Interdigital Nerve Pain

(Morton's Neuroma, Morton's Neural)

Interdigital nerve pain may be caused by nerve irritation (neuralgia) or persistent benign enlargement of the nerve (neuroma). Pain may be nonspecific, burning, or lancinating or may cause a foreign-body sensation. Diagnosis is usually by history and physical examination. Treatment may involve orthoses, local injection, or sometimes surgical excision.

Interdigital nerve pain along the distal innervation near the ball of the foot results primarily from ill-fitting or constrictive footwear or, less commonly, from nerve traction due to abnormal foot structure. Chronic repetitive trauma results in a thickening of the perineurium and thus a benign enlargement of the nerve (Morton's neuroma).

Symptoms and Signs

Symptoms are usually unilateral. Pain occurs around the metatarsal heads or the toes. Early symptoms often include an intermittent mild ache and discomfort in the ball of the foot, usually when a specific shoe is worn. As neuroma develops, pain worsens, often with a burning or lancinating quality or with paresthesias. In time, patients are unable to wear most shoes. While walking, patients often falsely sense a pebble in their shoes. The 3rd interspace is most often affected, followed by the 2nd.

Diagnosis

The symptoms are often specific, and the diagnosis is confirmed by localized tenderness with plantar palpation of the interdigital space. Although MRI does not usually confirm neuroma, it is sometimes used to rule out another interspace lesion or arthritis, which causes similar symptoms but is treated differently.

Treatment

Recent-onset neuralgia usually resolves quickly with correctly fitting shoes and insoles. Local anesthetic injection hastens improvement. In contrast, neuromas may require one or more perineural injections of long-acting corticosteroids with a local anesthetic. The needle, aimed distally, is inserted at a 45° angle to the foot's dorsal surface and into the metatarsophalangeal interspace. An appropriate orthosis often relieves symptoms. If conservative therapy is ineffective, excision often brings complete relief. However, another neuroma occasionally develops at the site of nerve excision (called amputation neuroma).

Metatarsophalangeal Joint Pain

Metatarsophalangeal joint pain usually results from misalignment of the joint surfaces caused by aberrant foot biomechanics. Pain occurs with walking and is accompanied by tenderness. Diagnosis is by history and physical examination. Treatment includes orthoses, sometimes local injection, and occasionally surgery.

Metatarsophalangeal joint pain is common among the elderly. Causes include hammer toe deformities, RA, and, less commonly, excess subtalar eversion and highly arched feet. Cushioning from the fat pad under the metatarsal heads is decreased. Interdigital neuralgia, Morton's neuroma, or osteoarthritic synovitis may result. Adventitial bursae may develop to compensate for the loss of cushioning.

Symptoms and Signs

Typically, the joint is generally achy, tender, or sore. Pain does not usually involve burning, numbness, tingling, or interspace pain, but these symptoms may develop if the joint is inflamed. Pain worsens during walking. Mild swelling with minimal heat occurs if osteoarthritic synovitis develops.

Diagnosis

Pain in the dorsal and plantar aspects of the joint with walking, with palpation, and during passive range of motion suggests the diagnosis.

Treatment

Orthoses redistribute and relieve pressure. Orthoses can also correct certain underlying abnormalities in foot biomechanics (eg, excessive subtalar eversion, highly arched feet). NSAIDs may relieve symptoms, but relief may be only temporary, depending on the disorder's severity. For osteoarthritic synovitis, local injection of a corticosteroid/anesthetic mixture may help. Surgery may be needed if conservative therapy is ineffective.

Sesamoiditis

Sesamoiditis is pain at the sesamoid bones under the 1st metatarsal head.

Sesamoiditis occurs in elderly people but is more common among active younger adults, particularly ballet dancers. It is also common among women who wear high-heeled shoes. The cause is usually repetitive pressure and flexion of the forefoot at the 1st metatarsophalangeal joint. Pain and tenderness occur at the sesamoid bones under the 1st metatarsal head; they become worse with weight bearing. Inflammation may be present and cause warmth, swelling, and redness. The diagnosis is highly likely if tenderness is localized to one sesamoid. Sesamoiditis should be differentiated from other disorders that cause metatarsal joint pain, which are more common among the elderly.

This topic was last updated May 2006.