MORTON’S NEUROMA

MORTON'S NEUROMA

The presence of an Morton’s neuroma between two of the lesser toes must be considered in the evaluation of metatarsalgia. The incidence is highest among middle-aged females, usually presenting unilaterally (85 percent) and occurring in the 3 to 4 interspace (45 percent) more frequently than the 2 to 3 interspace (37 percent). The incidence of simultaneous neuroma in the same foot is rare (less than 4 percent).

Morton's neuroma

ETIOLOGY

Ill-fitting high heeled shoes provoking increased intermetatarsophalangeal pressures place women at higher risk for the development of a “neuroma” or entrapment of the third branch of the medial plantar nerve (third web space). Chronic irritation of the sole of the foot on business is a serious risk factor for Morton’s neuroma.

SYMPTOMS

The most common presenting symptom is burning plantar foot pain in the involved intermetatarsal forefoot region exacerbated by weight bearing. The pain may extend to the toes.

CLINICAL EXAMINATION

Examination should attempt to differentiate metatarsophalangeal and metatarsal head symptomatology from those symptoms originating from the intermetatarsal spaces just proximal to the metatarsal heads. Gentle compression of the foot across the forefoot, simulating a “tight shoe”, is used to elicit a Mulder’s sign, which tends to reproduce the patients pain dramatically in the involved web space.

Mulder's sign: Indirect pressure of the metatarsal head elicit pain

Direct pressure to the neuroma produced pain

MRI and ultrasonography have been shown to document the location of a neuroma. Weight bearing x-rays are obtained to help exclude other causes of metatarsalgia.

Foot MRI: Morton's Neuroma in the 3rd intermetatarsal space

CONSERVATIVE TREATMENT

THERAPY:

CONSERVATIVE TREATMENT

Conservative treatment should include appropriate accommodative footwear that provides an adequate intermetatarsal girth and a relatively rigid sole in an attempt to limit metatarsophalangeal hyperextension on weight bearing.

Additionally a metatarsal bar provided by a soft insert or orthotic is typically used to relieve pressure in the symptomatic intermetatarsal region.

Intermetatarsal bursal injection of steroids (cortisone), has not proved to be clinically efficacious, noting only a 30% “cure” rate at 2 years after a series of injections. Inadvertent steroid injections into the adjacent metatarsophalangeal capsular region may provoke attenuation and rupture of collateral supporting structures of the metatarsophalangeal joint, resulting in toe divergence and metatarsalgia as well as plantar fatpad atrophy.

NSAID drugs relieves the symptoms temporarily.

OPERATIVE TREATMENT

THERAPY:

SURGICAL TREATMENT

The dorsal longitudinal approach for primary microsurgical excision of neuroma have been advocated and consider the final and permanent solution of the problem.

The duration of the microsurgical procedure is 30 min and the patient can walk immediately post op wearing a special orthotic shoe for 15 days. Hospital stay is not necessary.

Morton's neuroma in the 3rd intermetatarsal space

Morton's neuroma

CASE REPORT 1

Female 45 years old with chronic pain at the front foot, with worsening over time.
The profession is particularly challenging because the patient is walking daily several hours.