Understanding Tarsal Tunnel Syndrome
Tarsal tunnel syndrome (TTS) is a relatively rare but significant disorder that can cause discomfort and pain in the foot and ankle, including burning, tingling, or numbness sensations.
TTS, a neuropathy due to the compression of the posterior tibial nerve and its branches, can affect people of all ages, many of whom do not get a formal diagnosis.
There is a good reason, according to Very Well Health, that tarsal tunnel syndrome sounds like the much-more publicized carpal tunnel syndrome, which affects the wrist: both conditions involve a nerve being squeezed in a tight space.
“Tarsal tunnel syndrome is similar to carpal tunnel syndrome, which occurs in the wrist. Both disorders arise from the compression of a nerve in a confined space,” explains the American College of Foot and Ankle Surgeons.
Medical Mystery: TTS Often Underdiagnosed or Misdiagnosed
There is a touch of the “medical mystery” to TTS which was not defined as a disorder until 1962, is usually underdiagnosed, and often misdiagnosed as plantar fasciitis.
“Cases of [TTS] have been reported, but not as many as expected, thereby rendering the entity and diagnosis of this condition ambiguous,” according to a clinical communication to The American Journal of Medicine. “This may be because the symptoms are complicated and ignored by patients and health care professionals. Hence, tarsal tunnel syndrome could be overlooked or underdiagnosed, and thus, underreported.”
Adding to the difficulties of identifying and treating TTS is that there is no definitive test to diagnose the condition, and treatment options, including surgery as a last resort, are open for debate.
“The optimal treatment of TTS is still a controversial issue. The controversy is mainly due to its diagnostic difficulties,” said an article in a peer-reviewed medical journal.
What is Tarsal Tunnel Syndrome?
To understand tarsal tunnel syndrome, you first need to understand the tarsal tunnel and its purpose.
The American College of Foot and Ankle Surgeons says that the tarsal tunnel is a “narrow space that lies on the inside of the ankle next to the ankle bones. The tunnel is covered with a thick ligament (the flexor retinaculum) that protects and maintains the structures contained within the tunnel—arteries, veins, tendons, and nerves.”
The tarsal tunnel has an important role as those blood vessels, nerves, and tendons that travel via the tunnel provide your foot with movement and flexibility.
One of the nerves, the posterior tibial nerve, can become squeezed or compressed which can lead to the symptoms of TTS.
“However, the term tarsal tunnel syndrome is often broadly applied to any pain along the tibial nerve, which can result from a multitude of causes,” explains the National Organization for Rare Disorders (NORD).
The Signs and Symptoms of TTS
The Cleveland Clinic says that tarsal tunnel syndrome causes signs of nerve pain, usually in the inside of your ankle or the bottom of your feet.
Symptoms may worsen during or after physical activity. TTS signs and symptoms include:
- Burning or tingling sensation in the foot (often described as “pins and needles”.)
- Numbness in the sole of the foot and toes.
- Sharp, shooting pain along the inner side of the ankle and foot.
- Increased pain during activities or prolonged standing.
- Weakness in the foot muscles.
- Radiating pain up the leg from the ankle to the calf.
- Radiating pain may not be localized to one spot.
TTS pain can be severe enough to cause a patient to limp. While symptoms often alleviate with rest, those with the disorder long-term may start to feel pain during rest or at night in bed.
The Factors that Lead to Tarsal Tunnel Syndrome?
As detailed above, we know that tarsal tunnel syndrome is medically caused by the compression of the tibial nerve inside the tunnel, but what factors can lead to this happening?
There are a variety of factors that can cause TTS, including:
- Ankle injuries or trauma such as sprains, fractures, or valgus foot deformity.
- Swelling or inflammation within the tunnel, sometimes caused by disorders such as diabetes, hypothyroidism, or arthritis.
- Flat feet or fallen arches.
- Enlarged structures within the tunnel, including:
o Benign bony growth (exostosis).
o Enlarged veins (varicose).
- Tumors or cysts in the area, including:
o tumors consisting mainly of fat tissue (lipomas).
o tumors consisting of nerve fibers and ganglion cells (gangliomas).
o Tumors of the nerve sheath (schwannomas).
“For many people who develop tarsal tunnel syndrome, TTS is part of an overuse injury. More than 2 in 5 people with tarsal tunnel syndrome have a history of injuries such as ankle sprains,” says the Cleveland Clinic.
How is a TTS Diagnosis Made?
To diagnose Tarsal Tunnel Syndrome, a foot and ankle specialist will review your complete medical history, conduct a comprehensive physical examination, and may order diagnostic tests such as nerve conduction studies, electromyography (EMG), and imaging (MRI or ultrasound) to assess the nerve and surrounding structures.
“A diagnosis of tarsal tunnel syndrome is made based upon identification of characteristic symptoms, a detailed patient history, a thorough clinical evaluation, and a variety of specialized tests,” says NORD. “A diagnosis of tarsal tunnel syndrome is made based upon identification of characteristic symptoms, a detailed patient history, a thorough clinical evaluation and a variety of specialized tests.”
In addition to an EMG or MRI, your physician may call upon X-rays or CT scans.
“Proper diagnosis of TTS requires the expert attention of experienced neurologists and nerve specialists. It is important that the doctor determine the severity of the condition in order to recommend the most appropriate treatment plan, including surgery, if necessary,” says Johns Hopkins Medicine.
What are the standard treatments or therapies for TTS?
Standard treatment or therapies for tarsal tunnel syndrome typically start with conservative action, and many patients can manage TTS with at-home or over-the-counter remedies.
Conservative actions that can be taken at home include:
- Rest and activity modification.
- Ice application to reduce inflammation.
- Compression and elevation with a supportive elastic bandage or brace around the ankle.
- Nonsteroidal anti-inflammatory drugs (NSAIDs like Advil or Motrin) for pain relief.
- Orthotic devices or supportive footwear.
“Staying off of your foot for a few days or weeks can promote healing and prevent further injury,” says the Cleveland Clinic. “Use ice packs for up to 20 minutes, a few times a day. Icing your foot can reduce swelling and pain.”
NORD says that orthotics includes devices such as splints or braces that are used to protect or correct the position of the foot. In some cases, changing to looser or larger footwear to reduce tightness can relieve pain associated with TTS.
The Next Treatment Options for TTS after Home Remedies
When your tarsal tunnel syndrome pain persists and is not relieved by home remedies and over-the-counter treatments, then your foot and ankle specialist will have options to help.
At this stage, TTS treatment can include:
- Physical therapy to strengthen and stretch foot muscles.
- Corticosteroid injections to reduce inflammation.
- Immobilization of the foot and ankle via a cast.
- Surgery to relieve pressure on the tibial nerve in severe cases.
NORD points out that corticosteroid injections may not only alleviate pain but also serve as a diagnostic tool as pain relief from the injection near the affected nerve can confirm a TTS diagnosis.
“If TTS symptoms are still severe after trying nonsurgical treatments, your healthcare provider might recommend surgery. Operations are available that can release your tibial nerve or widen your tarsal tunnel. If a mass is putting pressure on your nerve, your surgeon will remove it,” says the Cleveland Clinic.
Surgery is the Last Resort if Conservative Treatment Fails
Johns Hopkins Medicine explains that one of the surgical procedures for TTS is called tarsal tunnel release surgery, where your foot and ankle surgeon will create an opening behind the ankle that extends down to the arch of the foot.
“The surgeon carefully divides the ligament, so it is not pressing against the tibial nerve,” says Johns Hopkins Medicine.
The peer-reviewed medical journal article says that when conservative treatment fails, and there is a clear identification of the cause of the entrapment, the surgical success rates are usually satisfactory with success rates varying from 44 to 96 percent.
“Surgical treatment achieves the best results in young patients, those with a clear etiology, a positive Tinel’s sign prior to surgery, a short history of symptoms, an early diagnosis, and no previous ankle pathology,” says the medical journal article.
Schedule a consultation today with the board-certified surgeons at Sweeney Foot & Ankle, who specialize in the treatment of tarsal tunnel syndrome and other foot and ankle neuropathy and pain.