Morton's Neuroma

Morton's Neuroma is a pathological condition of the common digital nerve, most frequently between the third and fourth metatarsals (third inter-metatarsal space). The nerve sheath becomes abnormally thickened with fibrous (scar) tissue and the nerve fibres eventually deteriorate.

This common digital nerve runs along the bottom (plantar) surface of the foot and branches to supply sensation to the plantar aspect and tips of the third and fourth toes. Occasionally, the common digital nerves in the second inter-metatarsal space are affected.

Very rarely the nerve in the first or fourth inter-metatarsal space is involved. The thickening of the nerve sheath compresses the nerve within the sheath causing the following symptoms:

Symptoms

• Pain most commonly in the ball of the foot and affecting one or two of the lesser toes (usually the third and fourth)
• Pain can sometimes radiate to the top of the foot
• The pain may can be intermittent in nature - it may disappear as quickly as it came
• Pain is often sharp, burning, or cramping in nature
• Pain may radiate into the tips of the toes or up the foot/ leg
• Aggravated by tight shoes and prolonged weight-bearing
• Removing the shoe often relieved the pain

Causes

• May involve mechanical irritation of the nerve
• Abnormal foot structure or mechanics (for example. flatfeet or excess foot pronation) contributes to irritation of the nerve
• Tight fitting footwear may contribute to the problem

What you can do

• Remove the shoe and massage your forefoot
• Rest the foot
• Wear shoes with a broad forefoot, low heel, and a good arch (e.g.. running or walking shoe)

What might a Podiatrist do?

• Order special diagnostic imaging to establish a diagnosis
• Identify why the Neuroma developed
• Physically manipulate the foot attempting to feel (palpate) the enlarged nerve
• Gently mobilize a joint to restore normal movement, applicable when restricted joint movement is causing nerve sheath irritation.
• If abnormal foot motion is causing compression/irritation of the nerve sheath your Podiatrist may prescribe Casted Orthotics to control abnormal foot motion
• Apply orthopaedic pads to relieve pressure on the nerve
• Use physical therapy ie ultrasound
• Inject powerful anti-inflammatory medication around the affected nerve
• Recommend surgical excision of the affected nerve generally a last resort (due to potential complications such as scar tissue, loss of normal sensation and recurrence)

Other causes of forefoot pain

• Metatarsalgia (pain and inflammation of the metatarsal bones and their soft tissue sheath)
• Capsulitis (pain and inflammation of the joints between the metatarsal bones and toes)
• Tendonitis (inflammation of the tendons which run along the top of the foot)
• Dislocation of a joint between a metatarsal and a toe (metatarsal-phalangeal joint)
• Severe plantar callus (callus on bottom of the foot) or bursitis (an inflamed fluid-filled sack often between a bone and an area of pressure)