13 Sep Tarsal Tunnel Syndrome
Tarsal tunnel syndrome (TTS) refers to compression of the posterior tibial nerve within the tarsal canal. At the level of the ankle, the posterior tibial nerve passes through a fibro-osseous canal and divides into the medial and lateral plantar nerves. TTS has been used loosely to cover a variety of neuralgias related to the posterior tibial nerve resulting from any cause. Some of the contributing factors include synovitis of the flexor tendons, inflammatory arthritis, fibrosis, ganglion cysts, fracture, and ankle venous stasis edema. Other conditions may also contribute to tarsal tunnel syndromes, such as hypothyroidism, severe pes planus, bony spurs in the tarsal tunnel, tumors/lipomas near the tibial nerve, and diabetes, which makes the nerve more vulnerable to compression.
TTS is characterized by pain in the retromalleolar and possibly the plantar medial heel regions of the foot and may extend to the toes. Sometimes, it is associated with numbness and tingling sensation. The pain is reported to be worse during standing and walking, but it may be present at rest in advanced cases.
The diagnosis is based on history and physical examination. A Tinel test is performed which involves tapping or palpating the posterior tibial nerve below the medial malleolus at a site of compression or injury to see if it induces distal tingling, a sign which indicates TTS. Additional tests may be performed to look for an underlying cause, such as electromyography, which is a test that can detect nerve dysfunction. MRIs may also be considered if a bony growth or a mass is suspected.
If left untreated, TTS can result in permanent and irreversible nerve damage, leading to worsening pain and even loss of motor function. It can be managed or cured with a wide variety of treatment options, but regardless of what the underlying condition is, it’s essential to get early treatment to prevent permanent nerve damage. Treatment for TTS ranges from foot inversion with braces or orthoses, corticosteroid injections, surgery, or a combination thereof. Conservative management includes strapping the foot in a neutral or slightly inverted position to reduce nerve tension. Painkillers, such as NSAIDs may be initially helpful for symptomatic relief.
A local corticosteroid/anesthetic mixture may be administered to improve inflammation and swelling. In refractory cases, surgical decompression may be necessary to relieve suspected fibroosseus compression of the nervous tissue. A minimally invasive surgery option is also available, which entails smaller incisions to introduce tiny instruments to stretch out the ligament. It incurs less trauma and tends to have a smaller risk of complications and an improved recovery time.
In some cases, these patents have to live with chronic severe pain from peripheral nerve entrapment, which is a risk factor for developing clinical depression. These patients should be identified as such and get proper psychological screening. Overall, TTS is a condition that needs to be accurately identified and treated to ensure rapid recovery and a successful clinical outcome.