Morton’s neuroma (MN) is a common foot condition causing significant pain and discomfort, often described as a burning sensation in the forefoot. It involves the thickening and irritation of tissue surrounding a digital nerve, typically located between the third and fourth toes. While successful treatment often provides relief, many patients worry about the pain returning. Whether a neuroma returns depends heavily on the specific treatment received and the underlying cause of the initial nerve irritation.
What Is Morton’s Neuroma?
Morton’s neuroma is a benign enlargement of the tissue surrounding a common plantar digital nerve in the foot, not a true tumor. It most frequently develops in the third intermetatarsal space, between the third and fourth toes. The condition arises from chronic compression and irritation of the nerve due to pressure from surrounding bones and ligaments. This repeated trauma causes the nerve sheath to thicken, exacerbating the compression and pain.
Classic symptoms include sharp, burning pain in the ball of the foot, numbness, or tingling in the toes. Patients often describe the feeling as walking on a wrinkled sock or a small pebble. Repetitive stress, improper footwear (like high heels or shoes with tight toe boxes), and underlying biomechanical issues are common contributing factors.
Standard Treatment Options
The initial approach to managing Morton’s neuroma generally involves conservative, non-surgical methods. Simple adjustments include wearing wide-toe-box shoes and utilizing custom orthotics to correct foot mechanics and relieve pressure on the forefoot. Nonsteroidal anti-inflammatory drugs (NSAIDs) may be used to manage pain in the short term by addressing inflammation.
When conservative changes prove insufficient, targeted injections are often the next step in treatment. Corticosteroid injections can provide relief that lasts for weeks or months by directly reducing inflammation around the irritated nerve. Alcohol sclerosing injections are another minimally invasive option, designed to chemically damage the nerve’s pain transmission ability.
If symptoms persist despite these non-surgical efforts, surgery becomes a consideration. The standard surgical procedure is a neurectomy, which involves the physical excision or removal of the affected portion of the nerve. An alternative surgical approach is decompression, where the deep transverse metatarsal ligament is released to provide more space for the nerve without removing it. Surgical intervention has historically shown high success rates, with some studies reporting good to excellent results in 80% to 89% of patients after primary neurectomy.
Why Neuromas Recur
Symptoms of Morton’s neuroma can return after initial treatment, particularly following surgery. When recurrence happens after a neurectomy, the most common cause is the formation of a stump neuroma. This is a painful mass that develops on the end of the nerve that was cut during the excision procedure.
A stump neuroma is essentially a failed attempt by the nerve to heal itself, resulting in a disorganized proliferation of nerve tissue at the surgical site. This complication causes a return of sharp, burning, neuritic pain, sometimes with greater intensity than the original neuroma. The risk of developing a painful stump neuroma is a significant cause of post-surgical pain, with rates reported as high as 35%.
Factors contributing to stump neuroma formation often relate to the initial surgical technique. The remaining proximal nerve stump must be buried deep into surrounding soft tissue, such as muscle, to protect it from pressure and friction. Inadequate nerve trunk removal or failure to properly transpose the nerve end into a protected location increases the likelihood of this painful mass forming. Recurrence can also occur if the initial diagnosis was incorrect, the resection was incomplete, or if the patient continues to experience significant biomechanical stress on the forefoot.
Managing Recurrent Morton’s Neuroma
When a patient experiences a return of symptoms, especially after a surgical neurectomy, the focus shifts to addressing the painful stump neuroma. The initial approach for a recurrent neuroma may still involve conservative treatments, such as targeted cortisone injections into the stump itself. However, secondary interventions are often necessary when conservative care fails to provide lasting relief.
Minimally invasive techniques offer an alternative to repeat surgery for managing recurrent symptoms. Cryoablation, also known as cryosurgery, uses a specialized probe to deliver extremely cold temperatures to the nerve stump. This freezing process destroys the nerve fibers and stops pain signal transmission without requiring a large incision or physically cutting the nerve again. Radiofrequency ablation (RFA) is another method that uses heat to deactivate the nerve tissue.
If symptoms are severe and unresponsive to ablation techniques, revision surgery may be necessary to correct the issue. This procedure typically involves excising the painful stump neuroma and then transposing the remaining nerve end deeper into the foot, sometimes into bone or thick muscle, to shield it from pressure and prevent a second recurrence. The goal of these advanced strategies is to permanently protect the sensitive nerve end from mechanical irritation.