Medial and Lateral Plantar Nerve Entrapment
Medial and lateral plantar nerve entrapment is symptomatic compression of the medial and/or lateral branches of the posterior tibial nerve at the medial heel and proximal arch. Diagnosis is clinical. Treatment involves orthotics and immobilization.
(See also Overview of Foot and Ankle Disorders.)
Symptoms of medial and lateral plantar nerve entrapment include almost constant pain, with and without weight bearing, which helps to differentiate medial and lateral plantar nerve entrapment from plantar fasciosis. The pain is often chronic, intractable, and aggravated by high-impact activities such as running. However, simple standing is often difficult. Burning, numbness, and paresthesias are usually absent.
Other signs of tarsal tunnel syndrome (eg, Tinel sign) are often absent.
Symptoms can be reproduced by palpation over the proximal aspect of the abductor hallucis, the origin of the plantar fascia, or both at the medial tubercle of the calcaneus.
With medial nerve entrapment, there is tenderness of the proximal medial arch beneath the navicular bone, sometimes with pain that radiates to the medial toes.
With lateral plantar nerve entrapment, there is tenderness over the plantar medial heel and abductor hallucis muscle.
Immobilization and foot orthoses to prevent irritating motion and pressure may be helpful, as may physical therapy and cryotherapy. If these treatments are ineffective, injection with a sclerosing agent that contains alcohol or careful surgical decompression of the nerve may help relieve pain.