Overview

Tarsal tunnel syndrome (TTS) is a neuropathic condition associated with damaged or compressed tibial nerves. The tibial nerve is a nerve located in the ankle, as shown in the image below.¹

The tibial nerve originates from the sciatic nerve, and it is one of the major nerves in the lower leg. It is responsible for sensory and motor innervation, and it also controls the muscle movement of the leg and foot.² Additionally, the tibial nerve travels down the back of the leg, passing through a narrow space in the ankle called the tarsal tunnel.³ Because of this, when pressure is applied, it compresses the tibial nerve inside this narrow space.³ This swelling can be due to intrinsic factors, such as abnormal growths like ganglion cysts (lumps in the joints) and thickened scar tissue.⁴ But it can also be a result of extrinsic factors, which include injury.⁴ Individuals from different age groups can be impacted by TTS; however, it is unknown to experts how many individuals are diagnosed with Tarsal Tunnel Syndrome, as many have not received a formal diagnosis.⁵ Having an awareness of the age-related differences in TTS is crucial for effective treatment.

Causes

As briefly mentioned, the compression of the Tibial nerve is due to both external and internal factors. 

External causes:

• Injuries: Ankle sprains, fractures, or post-surgery scarring
• Foot Structure Issues: Flat feet, high arches, or abnormal foot positioning
• Lifestyle Factors: Poorly fitted shoes, excessive running (especially with foot overpronation)
• Medical Conditions: Arthritis, diabetes, obesity, and swelling in the legs

Internal causes:

• Cysts and Tumours: Ganglion cysts, lipomas, or nerve growths
• Thickened Tissues: Scar tissue, enlarged ligaments, or bone spurs
• Vascular Problems: Swollen veins or restricted blood flow to the nerve⁶

The most common causes were found to be thickened tissues and vascular problems. TTS can be seen at any age but is relatively rare in children.^1,7 Nerve compression injuries are often associated with trauma, whereas in a small number of isolated cases, the exact cause is idiopathic (unknown).⁸ Idiopathic causes account for 20% of TTS cases.⁶ However, in adults, Tarsal Tunnel Syndrome may arise from underlying conditions that include diabetes, arthritis, low thyroid function or hereditary nerve issues.⁴

Epidemiology

TTS, despite being able to manifest at any age, is most commonly diagnosed in athletes and active adults.⁹ This includes intense periods of physical activity, which include walking and running,  using weights and standing.⁹ This is often due to injury, poorly fitted shoes, space-occupying lesions and growths pressing on the Tineal nerve or abnormal positioning and structure of the foot.¹⁰ Such as pes planus (flat feet) and hind foot valgus (heel deviates outwards from the midline of the body), which increases the risk of nerve compression.¹¹ Sports that also involve excessive upward foot movement (hyper-dorsiflexion) can also increase pressure in the tarsal tunnel, making athletes more likely to develop TTS.¹⁰

Although the incidence of TTS is unknown and underdiagnosed, the occurrences of TTS are more common in female populations compared to males.¹ TTS has been understudied in pediatric populations however, in the following study by Albrektsson et al. involving 10 pediatric patients with TTS, the participants were all female.¹²

Clinical presentation 

There is no difference in the literature regarding the presentation of TTS in both children and adults. The signs and symptoms of TTS vary depending on the location of nerve compression in the tarsal tunnel.¹⁰ The common presentation consists of numbness, burning, and painful paresthesia in the heel, inner ankle, and bottom of the foot.¹⁰ This can be exacerbated with physical activity, and whilst sleeping, pain may occur if the foot stays in a turned-out (everted) and bent (dorsiflexed) position during sleep.¹⁰ In more severe cases, the condition may progress into causing atrophy of the muscle of the bottom of the foot over time, as compression of the nerve may inhibit the muscle cells' normal signalling pathway in the foot. This disruption in the signalling pathway can limit an individual's foot movement. This leads to a loss of muscle mobility in the affected limb.¹⁰ Therefore, timely intervention and identification can limit these long-term complications from affecting both children and adults

Diagnosis 

TTS is often misdiagnosed and underdiagnosed, as no single examination can be used; therefore, your doctor or healthcare provider would first take a comprehensive history of a patient's symptoms and then follow up with a physical examination to confirm the diagnosis of TTS.¹³

Tests may include:

• Imaging tests such as MRI, radiographs and Ultrasound to exclude bony abnormalities and growths 
• Tinel’s test, which is when the doctor lightly taps the patient's tibial nerve, and if it causes pain or tingling similar to your symptoms, it could indicate TTS⁵
• An electromyograph, which monitors the electrical impulses in the foot
• Nerve conduction tests
• Blood tests to rule out systemic explanations such as diabetes or arthritis for TTS⁴

The Electromyograph and nerve conduction tests are helpful in the diagnosis of 80% of TTS cases.¹³ However, false negative tests are not uncommon.¹⁴

Management and treatment

The management of TTS in children and adults is similar in principle; however, there are some differences. The treatment can either be surgical or non-surgical; the cause of TTS, the degree of loss of function of the foot and ankle and the presence of muscle atrophy guide this choice.⁶ The goal of non-surgical treatment focuses on relieving pain and inflammation, which can include drug therapy such as non-opioid analgesics, ie, acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs). Neuropathic pain medication may also be prescribed; these medications work to specifically target nerve-related pain. This includes gabapentin, pregabalin, and tricyclic antidepressants, which modify how the nervous system processes pain signals, which helps to relieve pain.¹

Orthotic shoes can also be used to maintain the appropriate position of the foot, which reduces movements and increases the risk of nerve compression. Footwear that maintains a proper arch in the foot can also reduce symptoms, along with night splints and casts to aid in taking the pressure off the foot for the nerve to heal.¹ 

For children, non-invasive methods are favoured, such as ice, NSAIDs and the use of appropriate footwear and physical therapy, such as calf stretching, helping to increase mobility and alleviate pain in the affected area.¹ However, for adults, interventions such as corticosteroid injections for pain relief or ganglion cyst aspiration.¹ Surgical treatments are indicated if conservative treatment shows no results after 12-18 months in both patient populations, with surgical success rates being 44-96%.^1,7 Therefore, the goal of surgery for TTS relieve pressure on the tibial nerve by releasing the flexor retinaculum, which can become too tight in TTS.⁷

Summary

TTS is a neuropathic condition whose incidence is unknown and rare. This condition is caused by either intrinsic factors, such as injuries, lifestyle factors, underlying conditions or extrinsic factors, which include space-occupying lesions, abnormal bony growth and thickened scar tissue. This applies pressure to the tibial nerve, which is in the ankle, which impacts the foot's movement and sensory innervation, causing pain, numbness and a tingling sensation in the foot. The symptoms of TTS were similar in both children and adults; however, in contrast to management, the treatment approach differs. 

In children, non-invasive treatments such as ice, NSAIDs and the use of appropriate footwear and physical therapy, whilst in adults, more invasive modes of therapy may be utilised, such as corticosteroid injections before having potential surgery. 

Although the differences in both children and adults in both presentation and management are quite minimal, due to TTS being more common in active adults. More research needs to be done on the impact and presentation of TTS in the pediatric population because of the lack of literature available focusing on this patient demographic.

FAQ’s

How to prevent TTS?

There are no precise guidelines for preventing TTS, but following these general measures can be beneficial:

• Wear proper footwear
• Avoid prolonged standing or walking
• Warm up and stretch before physical activities
• Maintain an ergonomic workstation to lessen strain on the lower limbs
• Maintain foot posture and alignment¹

What happens if TTS is left untreated?

Pain and pressure in the foot and ankle can be caused by conditions other than TTS. It is important to book an appointment with the doctor if patients feel any symptoms such as pain, numbness and tingling of the foot. Delaying treatment can lead to complications in sensory and motor loss of the foot and deformities to the foot structure.¹