Morton's metatarsalgia

Morton's neuroma is a compression neuropathy of the interdigital nerve branches in forefoot, usually seen in the third intermetatarsal space (but can occur in other intermetatarsal spaces as well) (1,2,3)

• also referred to as Morton’s metatarsalgia, interdigital neuritis, Morton’s entrapment, interdigital neuralgia, interdigital neuroma, interdigital nerve compression syndrome, and intermetatarsal neuroma
• technically this condition is not a true neuroma , as a degenerative rather than a proliferative process is involved (1)
• charcterised by perineural fibrosis and nerve degeneration due to repetitive irritation of the digital nerve caused by repeated trauma, ischemia or entrapment of the nerve (2)

The exact incidence of the condition is unknown. Small studies have estimated the prevalence to be around 30%.

• occurs most frequently in women in middle-aged women, and the incidence is at least four to 15 times higher in females
• common causes include
  • narrow toe-box footwear
  • hyperextension of the toes in high-heeled shoe
  • deviation of the toes
  • inflammation of the intermetatarsal bursa
  • forefoot trauma
  • some high impact sporting activities such as running, football, basketball
  • metatarsophalangeal joint pathology
  • lipoma (1,2,3)

Reference:

• (1) Munir U, Morgan S. Morton Neuroma. [Updated 2017 Nov 13]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2018 Jan
• (2) Rout R at al. Morton's neuroma: diagnostic accuracy, effect on treatment time and costs of direct referral to ultrasound by primary care physicians. Qual Prim Care. 2009;17(4):277-82
• (3) Ata AM, Onat ŞŞ, Özçakar L. Ultrasound-Guided Diagnosis and Treatment of Morton's Neuroma. Pain Physician. 2016;19(2):E355-8.