Tarsal Tunnel Syndrome (Posterior Tibial Neuralgia)
Tarsal tunnel syndrome represents a compression or injury or stretch affecting the tibial nerve at the level of the Inside border / medial border of ankle and of the heel. The condition is slightly more common in women than men. The nerve irritation can occur because of " extrinsic compression " ex: A mass or bone spur outside the nerve pushing on it. Or can occur because of " tension factors " on the nerve related to malalignment of the arch of the foot. Or can occur because of "intrinsic factors " damage to the interior cellular structure of the nerve such as can occur with diabetes or inflammatory arthritic conditions.
Tarsal Tunnel Symptoms and Anatomy
- Burning pain on the inside border of ankle or heel
- Cramping in the arch or up in the meteor a call and leg
- Numbness and tingling and shooting pains
- Occasionally lateral border heel pain
Typical symptoms of tarsal tunnel syndrome include inside border or "medial " ankle pain which radiates into the heel or the arch or down into the toes. It can also radiate up into the leg. And if the lateral plantar nerve branch is involved the pain can even occur on the outside border / lateral border of the heel or of the foot.The quality of the pain is often described as burning or numbness or tingling or shooting sensations or cramping. The pain is often worse at night and during the later stages of high activity level such as running.
Tarsal Tunnel Anatomy
The tibial nerve involved in tarsal tunnel syndrome starts in the leg as a branch of the sciatic nerve . As the tibial nerve travels behind the inside border of the ankle and as it passes through the tarsal tunnel it divides into two smaller branches Dash medial plantar nerve and lateral plantar nerve. The tibial nerve at this location passes through and is confined within a tight space known as the tarsal tunnel. Inside the tarsal tunnel the nerve is accompanied by the posterior tibial artery, two veins, three tendons. Therefore , anything that occupies space or increases pressure within the space or anything changes alignment of the bones in that space can contribute to the symptoms of tarsal tunnel syndrome.
Tarsal Tunnel Diagnosis
A thorough history which includes patient description of paresthesias in the tibial nerve distribution and physical examination revealing positive tibial nerve Tinnels sign and tenderness along the course of the tibial nerve. weight-bearing x-rays and bio mechanical alignment assessment can typically confirm Malalignment causes for tarsal tunnel syndrome and assist in treatment . EMG nerve conduction study Testing can add objectivity to the diagnosis as well . Advanced imaging with IV contrast MRI may be indicated when there is concern about an extrinsic mass compression upon the tibial
Tarsal Tunnel Treatment
If tarsal tunnel syndrome is not due to extrinsic compression by mass then non-surgical treatment is appropriate - reserving surgery for nonresponsive / recalcitrant cases.
- Anti-inflammatory treatments including corticosteroid injection into the tarsal tunnel plus oral NSAID Plus anti-inflammatory icing
- Rehab treatments for tibial nerve glides and malalignment strengthening and stretching techniques And home exercise program instruction
- Alignment supports including ankle braces or foot orthotics
- Short term activity modification reducing impact activity six weeks and then restarting upon slow re-escalation schedule after initial treatment
Tarsal Tunnel Surgery
For patients with extrinsic compression by mass ( ganglion / bone spur ) or for patients that have failed prolonged conservative management , surgery would be indicated and is often successful with a low complication rate
Surgery includes removal of any extrinsic compression such as ganglion or bone spur as well as "Tarsal tunnel / Tibial Nerve Decompression " : consisting of release of the flexor retinaculum and neuroplasty( releasing tight or tethering tissue around the nerve ) of the tibial nerve to the level of bifurcation into medial plantar nerve and lateral plantar nerve branches .