MORTON’S NEUROMA

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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).

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.


LEFT FOOT MRI :   Morton's Neuroma between 4th and 5th metatarsal head-neck (red circle)


MRI LEFT FOOT:  Morton's Neuroma between 3rd and 4th metatarsal head neck in the same patient (red line)


Red spots reveals the Morton's neuromas in the left foot,  Surgical skin incision (black line on the 4th metararsal)


Morton's Neuroma between 3rd and 4th metatarsal (arrow).  Surgical excision


Morton neuroma woman 34 years old with severe forefoot pain


Morton neuroma 10X5mm

CASE REPORT 2

Female 56 years with severe pain in the forefoot - metatarsalgia, with worsening pain at the end of time especially when wearing closed shoes.

MRI, Morton's neuroma between 2nd and 3rd metatarsal head (left foot)


Morton's neuroma (green circle)


Morton's neuroma after surgical resection