Morton's Neuroma - Everything You Need To Know - Dr. Nabil Ebraheim

Dr. Ebraheim’s educational animated video describes the condition known as Morton's Neuroma.
Morton's Neuroma is a chronic irritation of the interdigital nerve, usually the one innervating the third web space. The irritation causes entrapment, compression and perineural fibrosis rather than a neuroma. The involved nerve is compressed or pinched as it runs between the third and fourth metatarsal heads under the deep transverse metatarsal ligament on the plantar aspect of the foot. Focal swelling of the nerve occurs secondary to the perineural and intraneural fibrosis. It usually affects middle aged females.
The patient complains of pain in the third web space between the third and fourth metatarsal, radiating to the third and fourth toes. Pain is worse with walking, weight bearing and with wearing narrow toed shoes. The pain is better with rest, elevation, removal of the shoes and massaging of the foot. The pain does not occur at night. The patient may complain of paresthesia at the bottom of the web space.
Examination:
•Squeezing the metatarsals together can cause shooting pain that will go into the third and fourth toes.
•The neuroma may be palpable.
•Tinels’ sign may be positive.
•Mulder’s sign: compression of the forefoot with one hand and simultaneously applying upward pressure on the affected web space with the thumb will produce pain and palpable click. The Mulder's sign or click does not occur in all cases.
Ultrasound may be helpful in diagnosis and MRI is rarely used.
The common digital nerve block may be confirmatory for diagnosis.
Differential diagnosis:
•MTP synovitis: patient will not have relief from the digital nerve block.
•Stress fracture
•Metatarsalgia
•Arthritis
•Lumbar disc herniation: L5 nerve root distribution.
Treatment
Nonoperative
•Wide shoe box
•Anti-inflammatory medication
•Injection of steroids
Surgery:
•In cases of failure of nonoperative treatment.
•Can do dorsal or plantar approach. Dorsal is more popular.
•Neurectomy or excision of the neuroma with release of the deep transverse intermetatarsal ligament. Resect the nerve as far proximal as possible to prevent recurrence of the neuroma and the symptoms.
•Complications of surgery: painful plantar scar and stump neuroma when resection of the nerve is not proximal enough.