Morton’s Neuroma

Morton’s Neuroma: Causes That Are Difficult to Pinpoint

The precise causes of Morton’s neuroma are still not fully understood. Some evidence suggests that the condition may result from a succession of micro-traumas (sports such as football, handball, tennis) and the wearing of narrow footwear. These situations can cause nerve compression, which may encourage the development of the condition.

Another theory considers the two functional components of the foot. The talar foot comprises the first three rays from the big toe and is responsible for propulsion. The calcaneal foot covers the last two rays and provides shock absorption. The up-and-down movement between these two components creates shearing forces that promote nerve irritation and neuroma formation.

Morton’s neuroma is diagnosed more frequently in women, particularly from the age of fifty onwards, often around the peri- or post-menopausal period.

Diagnosis of Morton’s Neuroma Pathology

The diagnosis of Morton’s neuroma is based above all on a rigorous clinical assessment, carried out by an experienced surgeon specialising in foot conditions.

The first step is a thorough clinical examination of the foot. The surgeon performs targeted palpation of the forefoot, looking for pain that is:

• very sharp,
• clearly localised,
• reproducing exactly the discomfort felt during walking,

A specific test known as the Mulder test is then performed. It involves compressing the forefoot transversely, looking for typical clinical signs such as the characteristic pain of Morton’s neuroma.

To confirm the diagnosis and rule out other causes of pain, imaging studies may be requested:

ultrasound, often preferred as it is more reliable than MRI for visualising the neuroma.

These supplementary investigations are not always necessary when the symptoms are sufficiently clear.

In all cases, the diagnosis takes into account:

• the precise location of the affected nerve (e.g. Morton’s neuroma at the big toe),
• the severity of symptoms,
• the morphology of the foot and the mechanical stresses involved.

The approach is individualised to ensure Morton’s neuroma is treated with the most appropriate method, whether medical or surgical.

These are typically mechanical symptoms: they appear during weight-bearing and walking, when the nerve is subjected to physical stress. They are aggravated by tight or high-heeled shoes and diminish or disappear at rest.

As soon as any of these symptoms appears, it is advisable to consult a foot and ankle specialist. Early management makes it possible to confirm the diagnosis, relieve the neuroma and slow the progression of the condition.

The International Elite Care surgeon favours minimally invasive or percutaneous techniques. These methods preserve tissue, optimising recovery and simplifying post-operative care.

Among these is neurolysis, which involves releasing the compressed nerve by cutting the ligament responsible for the compression. This procedure is performed through an open approach or percutaneously, with an incision of approximately 2 mm. The risk of failure and persistent pain is significant; this technique is generally reserved for smaller neuromas.

Another technique involves performing osteotomies on the metatarsal heads using percutaneous surgery. In cases where the metatarsal bones are excessively long, this corrects the weight-bearing pattern, reduces mechanical stress and decompresses the nerve.

In cases of significant nerve thickening, the nerve may have become too bulky and damaged to be treated by neurolysis alone. In such cases, nerve resection (neurectomy) may be performed. This means surgically removing a portion of the nerve to eliminate the pain permanently.

This procedure results in permanent loss of sensation at the tips of the affected toes, without affecting their mobility, muscular strength or stability.