Orthopedics - Oleksa A.P. 2006

Pain syndromes of the limbs
Foot neuromas

Forefoot pain can be caused, particularly when walking, by Morton's intermetatarsal neuroma.

A neuroma is a thickening of the intermetatarsal nerve characterized by nerve fiber demyelination and Connective Tissue hypertrophy. Morton's neuroma is considered an entrapment neuropathy that most commonly occurs in the third intermetatarsal space, where the medial and lateral plantar nerves form a common branch supplying the toes.

Constant pressure of the distal FOOT against a hard surface can injure the nerve as it is overstretched over the deep transverse metatarsal ligament. The nerve becomes taut and damaged due to excessive foot pronation during walking or specific occupational activities.

Patients complain of pain in the arch of the foot that radiates into the toes during walking and diminishes or disappears once the shoes are removed and the foot is massaged. This pain should be distinguished from neuralgia, which is characterized by typical "shooting" burning pain, paresthesia, tingling, and numbness.

Neuroma must also be differentiated from pain along the II or III metatarsal bone, which occurs in periostitis or stress fractures of these bones ("march fracture"). In stress fractures, pain is characteristic upon Palpation of the diaphysis of the affected metatarsal bone, and diaphyseal involvement is confirmed radiologically.

Pain arising during joint movement in the toe indicates arthrosis or Arthritis (most commonly associated with Hallux Valgus, Gout, etc.).

If pain occurs upon palpation over the metatarsal HEAD, it is likely caused by bursitis.

If examination reveals pain in the interspace between the third and fourth toes precisely posterior to the web space, a neuroma is most likely. Pain does not occur directly beneath the metatarsal head. "Mulder's click" may be elicited when the swollen neuroma becomes entrapped between the metatarsal heads.

From the data presented, it is evident that the Diagnosis of neuroma can in most cases be established clinically and confirmed by Magnetic Resonance imaging.

Treatment for foot neuroma can be either conservative or surgical. Conservative management includes fitting the patient with wide shoe inserts to reduce pressure on the neuroma site or recommending orthopedic footwear, along with nerve blocks using novocain, Kenalog-40, and Antibiotics, which provide analgesic and anti-inflammatory effects. If conservative treatment fails and the diagnosis of neuroma is firmly established, surgery—excision of the neuroma—is required.

Foot pain may also occur in association with hallux valgus, Deutschlander's disease, gout, and Other types of arthritis, as described in separate sections.