Morton’s neuroma is a painful foot condition affecting the nerves in the ball of the foot, often causing significant discomfort during walking or standing. This disorder involves a thickening of the tissue surrounding a digital nerve, usually located between the third and fourth toes. It is recognized as a frequent cause of forefoot pain. Understanding the nature, prevalence, symptoms, and management strategies for this condition is important.
Understanding the Pathology
Morton’s neuroma is not a true tumor but rather a thickening or enlargement of the tissue surrounding a nerve that runs between the metatarsal bones in the forefoot. This condition is more accurately described as a perineural fibrosis, which is the formation of fibrous tissue around the nerve. The nerve most commonly affected is the common plantar digital nerve, typically located in the third intermetatarsal space, between the third and fourth toes.
The physical change occurs when the nerve is subjected to chronic irritation, repetitive microtrauma, or excessive pressure. The nerve runs underneath the transverse intermetatarsal ligament, and compression against this ligament or adjacent bones causes damage. This constant squeezing leads to swelling, inflammation, and the eventual development of the characteristic fibrotic thickening within and around the nerve. This enlarged, fibrotic tissue then further compresses the nerve, creating a cycle of increasing pain and irritation.
Prevalence Rates and Demographics
Morton’s neuroma is a frequent condition. Experts estimate that the prevalence, including asymptomatic cases, may be as high as 30% to 33%. Although precise incidence rates for symptomatic cases are challenging to determine, it is a common cause of forefoot pain in clinical practice.
The condition is much more common in women than in men. Studies suggest the ratio of female to male admissions can be as high as 4:1, with some reports showing ratios up to 18:1. Middle-aged women are the most susceptible demographic, typically affecting individuals between the ages of 30 and 60.
Common Symptoms and Risk Factors
The classic presentation of Morton’s neuroma involves pain in the ball of the foot, which is often described as a sharp, shooting, or burning sensation. Many individuals report the distinct feeling of standing on a pebble, a marble, or a bunched-up sock located beneath the ball of the foot. This discomfort frequently radiates into the contiguous halves of the two toes supplied by the affected nerve.
Numbness, tingling, or a pins-and-needles sensation in the toes are also common symptoms associated with the condition. Symptoms tend to worsen with weight-bearing activities like walking or running, and they are particularly aggravated by wearing tight or narrow shoes. Relief can often be found temporarily by removing footwear and massaging the foot.
A major risk factor is the type of footwear regularly worn, especially high-heeled shoes or those with a narrow, pointed toe box. Such shoes force the forefoot bones together, increasing compression and irritation on the digital nerve. High-impact athletic activities, such as jogging or running, can also contribute to the development of the neuroma through constant microtrauma.
Certain pre-existing foot deformities can alter the foot’s biomechanics, placing more strain on the nerve and increasing the risk. These conditions include bunions, hammertoes, flat feet, and high arches. Any condition that disrupts the normal mechanical function of the foot can lead to increased pressure on the nerve.
Spectrum of Treatment Options
Treatment for Morton’s neuroma generally follows a progressive approach, starting with the most conservative measures. Initial management focuses on reducing compression and inflammation on the nerve to alleviate symptoms. Simple but effective changes include avoiding high-heeled shoes and selecting footwear with a wider toe box and a softer sole.
Over-the-counter or custom orthotic devices and metatarsal pads are commonly used to redistribute pressure away from the affected nerve in the forefoot. Nonsteroidal anti-inflammatory drugs (NSAIDs) can also be utilized to help manage the pain and reduce inflammation in the short term. These conservative strategies alone may provide relief for up to 50% of patients.
If conservative methods are insufficient, the next step involves targeted non-surgical interventions, such as injections. Corticosteroid injections deliver a powerful anti-inflammatory agent directly to the site of the neuroma, reducing swelling and providing pain relief for several months. Another option is alcohol sclerosing injections, which use concentrated alcohol to chemically destroy the nerve tissue, reporting success rates over 80% per single injection.
For patients whose symptoms persist despite comprehensive non-surgical management, surgical intervention may be considered. The most common surgical procedure is a neurectomy, which involves the physical removal of the affected portion of the nerve. Alternatively, nerve decompression surgery involves releasing the tight structures, such as the transverse metatarsal ligament, around the nerve without removing it. Surgical options generally have the highest success rates for long-term relief, often reported between 80% and 95%.