May 30, 2024

Tarsal tunnel Syndrome is a set of complex symptoms that affect the foot and in most instances, it is due to compression neuropathy of the posterior tibial nerve as it passes through the fibro-osseous tunnel beneath the flexor retinaculum in the median side of the ankle.

Clinical-Anatomy of tarsal tunnel syndrome

Medial plantar nerve supplies:

  • Abductor hallucis
  • Flexor digitorum brevis
  • Flexor hallucis brevis
  • First lumbrical

Lateral Plantar nerve supplies:

  • Remaining intrinsic muscles except for short toe extensors

Pathogenesis

Intrinsic:

  • Space occupying lesions (lipomas, ganglions)
  • Osteophytes in degenerative pathology
  • Hypertrophic retinaculum
  • Hemorrhage secondary to trauma

Extrinsic:

  • Varus
  • Valgus deformity
  • Edema
  • Direct trauma
  • Surgical scarring
  • Shoes

Both Intrinsic and Extrinsic

Clinical Features

Nocturnal burning pain awakens the patient and causes him to hang the leg over the edge of the bed, shake it manage it or walk for relief.

Intermittent burning pain, tingling, and numbness in toes and a distal portion; provocation by prolonged standing/walking

Relieve by rest/ removing shoes

Radiates to calf muscles

Nerve supply of foot

Findings in tarsal tunnel syndrome

  • Sensory decrease in the area of medial and lateral plantar nerves
  • Dorsal surface of the foot except for the distal phalanx unaffected
  • Decrease two-point discrimination
  • Tinel sign (+)
  • Tenderness is often found over the nerve at the medial portion
  • Slight weakness over toe flexion

Lab and radiological diagnosis

NCV and Electromyography

Treatment of Tarsal Tunnel Syndrome

Conservative treatment

  • Weight loss
  • Activity modification
  • Local injection of steroid
  • Shoe modification, orthosis, stretching exercises,
  • Medication: SSRI, NSAIDs

Surgical Treatment

Indications:

  • Failed conservative treatment for 3-6 months
  • Compressive mass
  • Positive EMG
  • Reproducible physical findings

Surgical Decompression Steps

  • Curvilinear incision 1 cm posterior to medial malleolus
  • The neurovascular bundle is isolated superior to the flexor retinaculum ( retinaculum is divided)
  • Nerve is freed distally the calcaneal branches are preserved
  • Wound closed
  • Immediate exercise initiated to reduce post-operative fibrosis

Anterior Tarsal Tunnel Syndrome

Entrapment of Deep peroneal nerve

  • Superficial: Inferior extensor retinaculum
  • Lateral: Lateral malleolus
  • Medial: Medial malleolus
  • Deep: Capsule of talonavicular joint

Contents

  • EDL
  • EHL
  • Tibialis anterior
  • Peroneus Tertius
  • Deep peroneal nerve
  • Dorsalis Pedis artery/ vein
Anatomy extensor retinaculum beneath structures

See also: Ulnar nerve compression

See also: Carpal Tunnel Syndrome (CTS)