What Is Tarsal Tunnel Syndrome?
Tarsal tunnel syndrome is similar to carpal tunnel syndrome in the wrist, but
it affects the ankle and foot. The tarsal tunnel is a narrow passageway on
the inside of your ankle, formed by bone and covered by a thick ligament
(the flexor retinaculum).
The posterior tibial nerve and several blood vessels and tendons run through
this tunnel. When the nerve becomes compressed or squeezed, it can cause pain,
tingling, numbness, or burning sensations in the foot.
Symptoms
- Tingling, burning, or "electric shock" sensations
- Numbness in the bottom of the foot or toes
- Pain along the inner ankle that may radiate into the arch and toes
- Symptoms that worsen with standing, walking, or activity
- Pain that's worse at night
- Symptoms that improve with rest
- Weakness in the small muscles of the foot (in severe cases)
Symptoms can vary from mild and intermittent to severe and constant,
depending on the degree of nerve compression.
Causes
Anything that creates pressure within the tarsal tunnel can cause this syndrome:
- Flat Feet: Fallen arches can strain the nerve
- Swelling: From ankle sprains, diabetes, or arthritis
- Cysts or Masses: Ganglion cysts, varicose veins, or benign tumors
- Bone Spurs: Bony growths that take up space in the tunnel
- Tendon Problems: Enlarged or inflamed tendons
- Diabetes: Makes nerves more susceptible to compression
- Previous Injury: Ankle fractures or sprains
Diagnosis
- Physical Examination: Tapping on the nerve (Tinel's sign) to reproduce symptoms
- Medical History: Understanding symptom patterns and risk factors
- Nerve Conduction Studies: Measuring how well the nerve transmits signals
- Electromyography (EMG): Testing muscle response to nerve stimulation
- MRI: Identifying masses, cysts, or other sources of compression
- Ultrasound: Visualizing the nerve and surrounding structures
Treatment Options
Non-Surgical Treatment
Conservative treatment is often effective, especially when started early:
- Rest: Reducing activities that aggravate symptoms
- Ice: Reducing swelling and inflammation
- Custom Orthotics: Supporting the arch and reducing nerve strain
- Supportive Footwear: Shoes that limit abnormal foot motion
- Bracing: Immobilizing the foot to reduce nerve stress
- Physical Therapy: Exercises and nerve gliding techniques
- Anti-inflammatory Medications: Reducing inflammation
- Corticosteroid Injections: Targeted relief of nerve inflammation
Surgical Treatment
When conservative treatments don't provide relief, surgery may be recommended.
The procedure, called tarsal tunnel release, involves:
- Making an incision along the tarsal tunnel
- Cutting the ligament to release pressure on the nerve
- Removing any masses or sources of compression
- Examining and freeing the nerve from any adhesions
Success rates are best when surgery is performed before permanent nerve
damage occurs, which is why timely diagnosis is important.
Recovery
- After surgery, most patients need to limit weight-bearing for several weeks
- Physical therapy helps restore mobility and strength
- Nerve healing is gradual - symptoms may improve over months
- Complete recovery depends on how long the nerve was compressed