Overview
Morton?s neuroma is inflammation, thickening, or enlargement of the nerve between the bones of the toes (metatarsal bones). The condition is also called intermetatarsal neuroma. The thickening is usually found between bones of the third and fourth toes of the foot, but sometimes it may develop between the second and third toes. It occurs when the medial plantar nerve near the bones of those toes becomes compressed or irritated, possibly because the metatarsal bones press against the nerve in the narrow gap between the toes. If left untreated, Morton?s neuroma can cause a sharp, burning, or shooting pain that often gets worse over time. The pain becomes worse when a person walks or stands on the ball of the foot. Sometimes the pain reaches the toes next to the neuroma and a sensation of tingling or numbness is felt.
Causes
Pronation of the foot can cause the metatarsal heads to rotate slightly and pinch the nerve running between the metatarsal heads. This chronic pinching can make the nerve sheath enlarge. As it enlarges it than becomes more squeezed and increasingly troublesome. Tight shoes, shoes with little room for the forefoot, pointy toeboxes can all make this problem more painful. Walking barefoot may also be painful, since the foot may be functioning in an over-pronated position.
Symptoms
The most common presenting complaints include pain and dysesthesias in the forefoot and corresponding toes adjacent to the neuroma. Pain is described as sharp and burning, and it may be associated with cramping. Numbness often is observed in the toes adjacent to the neuroma and seems to occur along with episodes of pain. Pain typically is intermittent, as episodes often occur for minutes to hours at a time and have long intervals (ie, weeks to months) between a single or small group of multiple attacks. Some patients describe the sensation as “walking on a marble.” Massage of the affected area offers significant relief. Narrow tight high-heeled shoes aggravate the symptoms. Night pain is reported but is rare.
Diagnosis
During the exam, your doctor will press on your foot to feel for a mass or tender spot. There may also be a feeling of “clicking” between the bones of your foot. Some imaging tests are more useful than others in the diagnosis of Morton’s neuroma. Your doctor is likely to order X-rays of your foot, to rule out other causes of your pain such as a stress fracture. Ultrasound. This technology uses sound waves to create real-time images of internal structures. Ultrasound is particularly good at revealing soft tissue abnormalities, such as neuromas. Magnetic resonance imaging (MRI). Using radio waves and a strong magnetic field, an MRI also is good at visualizing soft tissues. But it’s an expensive test and often indicates neuromas in people who have no symptoms.
Non Surgical Treatment
Nonsurgical treatment is tried first. Your doctor may recommend any of the following. Padding and taping the toe area, shoe inserts, changes to footwear, for example wearing shoes with wider toe boxes or flat heels, Anti-inflammatory medicines taken by mouth or injected into the toe area, nerve blocking medicines injected into the toe area, other painkillers, physical therapy. Anti-inflammatories and painkillers are not recommended for long-term treatment. In some cases, surgery is needed to remove the thickened tissue and inflammed nerve. This helps relieve pain and improve foot function. Numbness after surgery is permanent.
Surgical Treatment
Surgery to excise the neuroma is usually performed under general anaesthetic in a day surgery facility. After surgery you will have to keep your foot dry for two weeks. Generally neuroma surgery allows for early weight bearing and protection in some type of post op shoe gear. Some neuromas may reoccur, but this is rare. Most studies on patient satisfaction after neuroma surgery show approximately 90% reduction of pain and about 85% of all patients rated the overall satisfaction with the results as excellent or good.