Morton's Neuroma

Is a painful benign fibrotic enlargement of one of there common digital nerves. It is caused by a shearing force of the adjacent metatarsal bone. It most commonly affects the third common digital nerve. Morton's Neuroma is found to be more common in females. This may be related to the type of shoe gear often worn by females. It is most common in the 4th - 6th decade.


History

Obtaining an accurate history is important to making the diagnosis of Morton's neuroma.

Common Findings

• Pain in the forefoot and corresponding toes adjacent to the neuroma
• Pain is usually described as sharp and burning
• Pain may radiate proximal
• Numbness and tingling often is observed in the toes adjacent to the neuroma
• Intermittent pain
• Massage of the affected area may give some relief
• Narrow tight high-heeled shoes aggravate the symptoms
• Patients may feel as though they are walking on a wrinkle in there sock

Exam

• Firm squeezing of the metatarsal heads with one hand while applying direct pressure to the dorsal and plantar interspace with the other hand may elicit radiating pain.
• Mulder Sign - A silent palpable click produced by the lateral squeeze test. The neuroma moves between the metatarsals.
• Passive and active bending of the toe in an upward direction may aggravate symptoms.
• Sullivan's Sign - Toes adjacent to the affected interspace splay apart on weight bearing.

Imaging

• Ultrasonography
• MRI

Differential Diagnosis

• Stress fracture of the metatarsal
• Rheumatoid arthritis
• Hammertoe
• Metatarsalgia- plantar tenderness over the metatarsal head
• Neoplasms
• Metatarsal head osteonecrosis
• Freiburg osteochondrosis- characterized by interruption of the blood supply of a bone followed by localized bony necrosis.
• Ganglion cysts
• Intermetatarsal bursal fluid collections

Treatment

Treatment strategies for Morton's neuroma range from conservative to surgical management.


Conservative

Bio mechanical

• Orthotics

Medications

• Injections- Corticosteroid- Anti inflammatory agent
• Alcohol sclerosing- Causes a chemical neurolysis of the nerve and used as an alternative to surgery for Morton's neuroma
• NSAID's- Non Steroidal Anti Inflammatory such as Ibuprofen or Naprosyn
• Tricyclic Antidepressants- Amitriptyline(Elavil)
• Anticonvulsants- Neurontin (Gabapentin)
• Pregabalin (Lyrica)
• Duloxetine (Cymbalta)

Rehabilitation Program
Physical Therapy

• Cryotherapy-Cold Therapy- Cold may be applied using an ice bag or a cold pack
• Ultrasonography- Sound waves that are transferred to a specific body area via a round-headed probe. The sound waves travel deep into tissue, creating gentle heat. The heat helps relieve pain and inflammation
• Deep tissue massage
• Stretching exercises
• Phonophoresis- Has been used in an effort to enhance the absorption of topically applied analgesics and anti-inflammatory agents through the therapeutic application of ultrasound

Surgical Intervention

• Neurectomy- When conservative measures for Morton's neuroma are unsuccessful surgical excision may be beneficial