Morton's neuroma

The Morton's neuralgia, also Morton 's metatarsalgia, Morton 's syndrome or Morton 's neuroma is a painful condition in the feet, starting from a compression (neural entrapment ) of the plantar nerves ( Nervi plantar tibial nerve ) between the heads of the metatarsal bones. It usually occurs between the metatarsals III and IV in the third interdigital space, more rarely between II and III. In up to 16% of cases also multiple Morton's neuralgia place on the same foot.

History

The first description of a neuroma in the intermetatarsal in 1835 by the Italian Filippo Civinini, while the first description of the symptoms on Durlacher 1845 returns. The namesake T. G. Morton described in 1876 a Metatarsalgia, but he then assigned to the fourth metatarsophalangeal joint.

Histology and Anatomy

Initially, a Bindegewebsverdickung was often described by the affected nerve in terms of fibrosis or perineural fibrosis, and there are also studies showing an accompanying demyelination and endoneurial fibrosis, a thickening and swelling of the nerve. However, other studies could have no difference to asymptomatic nerves. Similarly, ischemic changes were described, but could not be confirmed as well. Since no consistent pathological change in a Morton neuralgia is present, it is recommended to avoid the term " Morton 's neuroma ".

In general, however, applies a mechanical narrowing in terms of a nerve compression syndrome of the interdigital nerve branch as the cause. The throat and occasional thickening of the nerve is usually distal and plantar intermetatarsal ligament profundum near the long toe flexor tendons.

While the interdigital nerves of the first and second toes gap branches of the ulnar medial plantar are and springs from the interdigital nerve of the fourth interdigital space of the plantar nerve lateral to branches of both plantar nerves unite to interdigital nerve in the third interdigital space, which was therefore potentially larger and more vulnerable.

Clinic

Symptoms are acute lancinating severe pain with the typical location of pain in the midfoot in patients mostly with splayed feet. At clinical examination, pressure pain point in this area.

Causes

Between the heads of the metatarsal bones run small nerve endings. If they are constantly irritated, a ganglion may form, causing pain and numbness. The neuroma is thus a reaction of the plantar nerves in chronic mechanical irritation such as when splay. Histologically fibrosis in the area of nerves in chronic ischemia.

Diagnosis

The clinical diagnosis is confirmed before any surgery with ultrasound or magnetic resonance imaging. The size of the Morton neuroma is important. Morton's neuroma with a transverse diameter less than 5 mm are often (about 30 %) found in asymptomatic persons. Frequently in the ultrasound or magnetic resonance imaging, an additional or a different localized Morton 's neuroma is ( rather than between the second and third toe, between the third and fourth toe or vice versa) have been found. Therefore, after such investigation the actions of the surgeon is decisively influenced.

Therapy

Spreizfußbehandlung, local anesthesia
At Beschwerdepersistenz surgical removal of the neuroma of plantar or dorsal.
Insert with special relief for the affected intermetatarsal space.