Morton neuromas are focal areas of symptomatic perineural fibrosis around a plantar digital nerve of the foot. The abnormality is non-neoplastic and does not represent a true neuroma. It may more correctly be known as Morton?s metatarsalgia. The condition is thought to be due to chronic entrapment of the nerve by the intermetatarsal ligament. It most often occurs in middle-aged individuals and is many times more common in women than men. Approximately 30% of asymptomatic middle-aged persons have the radiological pathologic findings of a Morton?s neuroma.
Morton’s Neuroma is a caused by pressure, abnormal function/motion or an imbalance in the structure of the foot such as flat feet, that causes an abnormal pressure on the structures and the nerves in the ball of the foot. It most commonly affects the nerve that goes to the 2nd 3rd or 4th toes. The squeezing of the nerve from abnormal motion leads to a protective thickening of the sheath that protects the nerve. Symptoms of Morton’s Neuroma often occur during or after activities that cause a sidewards squeezing of the ball of the foot or from pressure such as walking, standing, or playing sport. Since squeezing is a common cause of the condition, shoes such as pointed toes or high heels can often lead to a neuroma. Shoes that are constricting, even tight sneakers, can pinch the nerve between the toes, causing inflammation and pain.
Outward signs of Morton’s neuroma, such as a lump, are extremely rare. Morton’s neuroma signs and symptoms, which usually occur unexpectedly and tend to worsen over time, include, pain on weight bearing (while walking) – a shooting pain affecting the contiguous halves of two toes, which may be felt after only a short time (of weight bearing). Sometimes there may be a dull pain rather than a sharp one. Most commonly, pain is felt between the third and fourth toes. Typically, a patient will suddenly experience pain while walking and will have to stop and remove their shoe. Burning. Numbness. Parasthesia, tingling, pricking, or numbness with no apparent long-term physical effect. Commonly known as pins-and-needles. A sensation that something is inside the ball of the foot.
The physician will make the diagnosis of Morton’s neuroma based upon the patient’s symptoms as described above in an interview, or history, and a physical examination. The physical examination will reveal exceptional tenderness in the involved interspace when the nerve area is pressed on the bottom of the foot. As the interspace is palpated, and pressure is applied from the top to the bottom of the foot, a click can sometimes be felt which reproduces the patient’s pain. This is known as a Mulder’s sign. Because of inconsistent results, imaging studies such as MRI or ultrasound scanning are not useful diagnostic tools for Morton’s neuroma. Thus the physician must rely exclusively on the patient’s history and physical examination in order to make a diagnosis.
Non Surgical Treatment
Ice therapy and anti-inflammatory medications or supplements. If conservative care measures fail to resolve your problem, some foot care providers may recommend a cortisone injection around your involved nerve to help reduce your swelling and inflammation. Concentrated alcohol injections around your affected nerve have also shown good results and should be considered before undergoing neurectomy, a surgical procedure to remove the enlarged, traumatized portion of your involved nerve.
Surgery for neuroma most often involves removing affected nerve in the ball of the foot. An incision is made on the top of the foot and the nerve is carefully removed. Surgeon must remove the nerve far enough back so that the nerve doesn?t continue to become impinged at the ball of the foot. Alternatitvely, another type of surgery involves releasing a tight ligament that encases the nerve. Recovery after Morton?s neuroma (neurectomy) surgery is generally quick. Typically patients are walking on the operated foot in a post-surgical shoe for 2 – 4 weeks, depending on healing. Return to shoes is 2-6 weeks after the surgery. Factors that may prolong healing are age, smoking, poor nutritional status, and some medical problems.
Although the exact causes of neuromas are not completely known, the following preventive steps may help. Make sure your exercise shoes have enough room in the front part of the shoe and that your toes are not excessively compressed. Wear shoes with adequate padding in the ball of the foot. Avoid prolonged time in shoes with a narrow toe box or excessive heel height (greater than two inches).