Tarsal

peripheral neuropathy caused by chronic or acute compression of the tibial nerve by the flexor retinaculum of the foot at the medial ankle

• Trauma (most common): fracture or sprain of the ankle (talus, calcaneus, medial malleolus)

• Rheumatoid arthritis

• Bone spurs, tumors, cysts, nerve ganglions

• Symptoms develop in areas innervated by the tibial nerve (distal to the medial malleolus):

  • Neuropathic pain and paresthesia in the heel, sole of the foot, and first three toes

  • Weakness and atrophy of intrinsic foot muscles (severe cases)

• Symptoms worsen with walking, prolonged standing, and at night

• Usually a clinical diagnosis

  • Positive Tinel sign: radiating paresthesia triggered by tapping the flexor retinaculum posterior to the medial malleolus

  • Pain upon foot dorsiflexion with eversion

  • Diminished sensation on the plantar area of the foot

• Nerve conduction studies: slow conduction velocity in the medial and lateral plantar nerves

• Initially conservative

  • Rest, NSAIDs, physiotherapy, use of orthotic shoes

  • Corticosteroid injection (if no improvement)

• Surgery

  • Indications: lack of response to conservative treatment or documented entrapment of the tibial nerve

  • Procedure: Division of the flexor retinaculum of the foot to decompress the tibial nerve