Morton’s metatarsalgia is a condition associated with a painful neuroma* on the digital nerve causing pain in the foot. Charcterised by perineural fibrosis and nerve degeneration due to repetitive irritation, is thought to be due to irritation of the digital nerve caused by repeated trauma, ischemia or entrapment of the nerve, occurs most frequently in women aged 40-50 who wear high-heeled, pointed-toe shoes. The neuroma occurs at the level of the metatarsal necks. The common digital nerve to the third/fourth metatarsal spaces is most often affected, although other interspaces can be involved.
Various factors have been implicated in the precipitation of Morton’s neuroma. Morton’s neuroma is known to develop as a result of chronic nerve stress and irritation, particularly with excessive toe dorsiflexion. Poorly fitting and constricting shoes (ie, small toe box) or shoes with heel lifts often contribute to Morton’s neuroma. Women who wear high-heeled shoes for a number of years or men who are required to wear constrictive shoe gear are at risk. A biomechanical theory of causation involves the mechanics of the foot and ankle. For instance, individuals with tight gastrocnemius-soleus muscles or who excessively pronate the foot may compensate by dorsiflexion of the metatarsals subsequently irritating of the interdigital nerve. Certain activities carry increased risk of excessive toe dorsiflexion, such as prolonged walking, running, squatting, and demi-pointe position in ballet.
You may initially experience a tingling sensation in the space between your toes, which gets worse over time. This leads to cramp in your toes and a sharp shooting or burning pain on the ball of your foot or at the base of your toes. The pain is often worse when walking or wearing shoes that press on the affected area. This is caused by irritation of the nerve between your toe bones (metatarsal bones). The tingling will eventually lead to pain, which can get worse over time. You may also experience cramping of your toes. The pain is usually felt as a sharp shooting or burning pain on the ball of the foot or at the base of the toes, which is often made worse when you’re walking. Some people with Morton’s neuroma feel anxious about walking or even placing their foot on the ground. The pain is likely to be more intense if you wear tight shoes, so wearing shoes that have more room in the toe area can help. Rubbing your foot may also lessen the pain.
A thorough subjective and objective examination from a physiotherapist is usually sufficient to diagnose a Morton’s neuroma. Investigations such as an X-ray, ultrasound, MRI, CT scan or bone scan may sometimes be used to assist with diagnosis, assess the severity of the injury and rule out other conditions.
Non Surgical Treatment
Common treatments involve wearing different shoes or using arch supports. Resting the foot, massaging the toes and using an ice pack may work for some people. A GP or a podiatrist (foot specialist) may also recommend anti-inflammatory painkillers or a course of steroid injections. Numbing injections, in which alcohol and a local anaesthetic are injected into the affected area of the foot, may also be effective. In extreme cases, when the condition does not respond to treatment, day case surgery may be needed.
Majority of publications including peer review journal articles, surgical technique description and textbooks promote surgical excision as a gold standard treatment. Surgical excision is described as the most definitive mode of treatment for symptomatic Morton?s neuroma with reported success rates varying between 79% and 93%. Various surgical techniques are described, essentially categorised as dorsal versus plantar incision approaches. Beyond this the commonest technical variation described as influencing the outcome of surgery involves burying and anchoring transacted nerve into soft tissue such as muscle.