Review Question - QID 106157

This patient presents with the signs and symptoms of a Morton's neuroma, which is a benign neuroma affecting one of the intermetatarsal plantar nerves.

Morton's neuroma is the most common cause of foot neuralgia, most often affecting women younger than 50 years of age. It is primarily caused by repetitive damage to the metatarsal heads; risk factors include running and wearing tight shoes or high heels. It typically presents with pain in the 2nd or 3rd web spaces. Diagnosis relies on history and physical. Mulder's sign is used as a diagnostic tool and is considered positive if there is a click and reproduced pain when the two metatarsal heads are squeezed with one hand while putting pressure on the interdigital space with the other hand.

Joong and El-Khoury describe the radiological findings in patients with chronic foot pain. They state that Morton's neuromas are most often encountered in the space between the 3rd and 4th metatarsals, followed by the space between the 4th and 5th metatarsals. High-definition US and MRI can be used for visualizing Morton's neuromas. They state that MRI is only utilized when the diameter of the lesion is greater than 5 mm and there are clinical findings present.

Adams II reviews the diagnosis and treatment of Morton's neuromas. He states that treatments can be both surgical or non-surgical in nature. Conservative non-surgical treatments should be attempted first and include reducing nerve pressure with the use of orthotics, metatarsal pads, and avoiding high heeled shoes, as well as oral medications. Furthermore, injections with corticosteroids and anesthetics are also utilized. Lastly, if conservative management fails, surgical treatments are utilized and include decompression, excision, and cryogenic neuroablation.

Illustration A demonstrates the typical localization of a Morton's neuroma, with a view of the normal anatomy in the smaller box. Illustration B shows the technique for eliciting Mulder's sign, which is positive in Morton's neuroma.

Incorrect answers:
Answer 1: A bony outgrowth, or bony spur, does not present with the same symptoms as a Morton's neuroma.
Answer 2: Intermetatarsal bursitis can lead to nerve compression and similar symptoms as a Morton's neuroma, but you would not expect to find a positive Mulder's sign.
Answer 4: Compression fractures can occur due to repetitive trauma, but you would not expect to find the classic signs of Morton's neuroma.
Answer 5: Plantar fasciitis typically leads to heel pain and you would not expect to find the classic signs of Morton's neuroma.