This is a painful condition affecting a small nerve in the foot. It occurs when the five long bones that run the length of the foot get pushed together, pinching the nerve in between. This friction on the nerve causes it to thicken and inflame causing pain. The condition gets its name from an American surgeon, George Morton.
Unfortunately, the cause of Morton?s Neuroma remains unknown to researchers. It is likely that a variety of factors may play a role in the development of this condition, including the presence of chronic pain conditions like fibromyalgia. Factors that may contribute to the development of Morton?s Neuroma include Wearing improperly fitting shoes can cause pressure on your foot, leading to swelling around the toe nerves. High heels are of particular concern as they cause a large amount of weight to be shifted to the ball of the foot. Repetitive activities like jogging, walking, and aerobics can also place a lot of pressure on the feet. This could lead to Morton?s Neuroma. Having a previous foot or muscle injury may cause you to hold your foot in a poor position when walking, contributing to nerve inflammation. Some people are just born with poorly shaped feet. People with extremely low arches or “flat feet” may suffer from Morton?s Neuroma more than others.
It usually occurs in between the 3rd and 4th toes (about 65% of cases) as is pictured to the right. It is less commonly found in the 2nd webspace, and rarely at all in the 1st or 4th webspaces. You can also experience pins and needles and/or numbness as a result of the nerve being affected. The condition tends to occur predominantly in middle aged females.
The clinical symptoms should quickly lead your doctor to suspect a neuroma. When examined, the doctor may feel a “click” which is known as Mulder’s sign. There may be tenderness in the interspace. The metatarsal bones will also be examined both clinically (and often with an xray). Tenderness at one of the metatarsal bones can suggest an overstress reaction (pre-stress fracture or stress fracture) in the bone. An ultrasound scan can confirm the diagnosis and is a less expensive and at this time, at least as sensitive a test as an MRI. An x-ray does not show neuromas, but can be useful to “rule out” other causes of the pain.
Non Surgical Treatment
Pain is the main reason that you seek treatment for a neuroma. Analgesics may help. Inflammation it best eased via ice therapy and techniques or exercises that deload the inflammed structures. Anti-inflammatory medications may help. Your physiotherapist will use an array of treatment tools to reduce your pain and inflammation. These include: ice, electrotherapy, acupuncture, deloading taping techniques, soft tissue massage and orthotics to offload the irritated nerve. One of the biggest factors in relieving pain may be changing or modifying your footwear. This may mean adding felt, foam or gel products to your shoe to help offload the area, or looking at avoiding tight fitting heels or shoes.
Operative treatment of Morton?s neuroma should be entertained only after failure of non-operative management. Standard operative treatment involves identifying the nerve and cutting (resecting) it proximal to the point where it is irritated/injured. This is usually done through an incision on the top (dorsal) aspect of the foot, although an incision on the sole (plantar) aspect of the foot can be used. Some physicians will attempt to treat Morton?s neuroma by releasing the intermetatarsal ligament, and freeing the nerve of local scar tissue. This may also be beneficial.