Tarsal Tunnel Syndrome | posterior tibial neuralgia
Recently, doctors writing in the medical journal Foot had this to say about the diagnosis of Tarsal Tunnel Syndrome.
Tarsal tunnel syndrome is classified as a focal compressive neuropathy (a direct pressure) on the posterior tibial nerve (a branch of the sciatic nerve that runs into the heel. This is why it is also diagnosed as posterior tibial neuralgia.)
The condition is rare and regularly under-diagnosed leading to a range of symptoms affecting the plantar (sole) of the foot. There are many intervention strategies for treating tarsal tunnel syndrome with limited robust evidence to guide the clinical management of this condition. The role of conservative versus surgical interventions at various stages of the disease process remains unclear.1
Confusion and difficulty in diagnosis
Tarsal tunnel syndrome is caused by abnormal pressure on the posterior tibial nerve or its associated branches as it passes through the tarsal canal.
The tarsal canal is formed by the flexor retinaculum, strong ligaments which include the laciniate ligament on the outside and the ankle bone on the inside. It is entrapment of the posterior tibial nerve under the laciniate ligament that leads to a diagnosis of tarsal tunnel syndrome.
In addition, the tibial nerve splits into three different pathways, one to the heel, and the other two to the bottom of the foot. This pain in different parts of the foot leads to the difficulty in diagnosis we mentioned above.
Many things can cause diagnosis of Tarsal Tunnel Syndrome
External traumas such as crush injuries, stretch injuries, fractures, dislocations and strains of the foot and ankle, can contribute to the development of tarsal tunnel syndrome.
Intrinsic issues such as soft-tissue masses may also contribute to compression neuropathy of the posterior tibial nerve. Bony prominences may be causative factors, such as a valgus deformity of the hindfoot (ankle and heel) which may increase tension due to excessive eversion and dorsiflexion (unnatural rotation).
It’s important to note that the pain experienced in the ankle with tarsal tunnel syndrome is often referred pain and may be due to injured or weakened ligaments at the ball of the foot. The problems with diagnosis is the problem of the sprain or weakening of the metatarsal, lateral collateral and medial collateral ligaments, ligaments which are causing the pain and are rarely examined by a family physician or an orthopedic surgeon.
Is it plantar fasciitis?
Metatarsal ligament weakness is manifested by pain at the ball of the feet which often radiates into the toes. This is called metatarsalgia. Chronic metatarsal ligament weakness and arch weakness is known as plantar fasciitis. Fasciitis can cause numbness in the foot and toes in the same areas of pain. Pain and numbness in the foot can also be caused by ligament and tendon laxity in the knee. The lateral collateral ligament can refer pain and numbness down the lateral side of the leg and foot and the medial collateral ligament down the medial side.
What are the symptoms of tarsal tunnel syndrome?
Symptoms of tarsal tunnel syndrome vary from individual to individual, but typically present as:
- Vague symptoms of pain in the ankle, arch, toes, or heel.
- Foot pain is often in the plantar aspect of the foot.
- Sensory disturbances also vary. Some individuals experience a slight pain, burning or tingling in the sole of the foot.There may be sensitivity to touch and temperature along the course of the nerve. Sometimes there is sharp pain and other times a loss of sensation.
- As the condition worsens, motor disturbances, weakness, atrophy, numbness, and gait abnormalities of the foot and ankle may occur.
- If pressure is kept off the foot and ankle, the symptoms may decrease; likewise, they will get worse if the foot and ankle are strained excessively. Although symptoms may subside with rest, they typically do not disappear altogether.
Treatment of Tarsal Tunnel Syndrome
A standard practice is to use steroids or to prescribe anti-inflammatory medications. Cortisone injections are also frequently recommended. These medications generally produce short-term pain benefit. However, they both have been shown to actually inhibit the healing process of soft tissues and accelerate cartilage degeneration.
Surgery, too, can make the condition worse, especially when the condition has been misdiagnosed (which is often the case). Metatarsal, lateral collateral and medial collateral ligament laxity should always be evaluated prior to making the diagnosis of tarsal tunnel syndrome. Surgery for this condition should not be done until a physician who understands the referral patterns of ligaments and is experienced in Prolotherapy performs an evaluation.
The Prolotherapy approach to treating Tarsal Tunnel Syndrome
We typically confirm an actual tarsal tunnel syndrome diagnosis using EMG/NCV studies, which measure the rate of nerve conduction. Confirmation of the diagnosis as well as the stage of the syndrome is determined by the degree of slowing of the nerve conduction. If the syndrome is detected in the early stages, Neural Therapy treatment is performed. This is a gentle healing technique developed in Germany that involves the injection of local anesthetics into autonomic ganglia, peripheral nerves, scars, glands, acupuncture points, trigger points, skin and other tissues.
Vitamin B and other natural supplements may also be prescribed. If, on the other hand, the tarsal tunnel syndrome is at an advanced stage, surgery may be necessary.
If the symptoms of tarsal tunnel syndrome are found to be due to weakened ligaments, then strengthening of the weakened ligaments in the foot with Prolotherapy would be recommended. Ligament weakness around the knee, hip, sacroiliac joint or pelvis can also cause radiating pain and numbness in the foot area.
Is it lumbosacral radiculopathy?
Tarsal tunnel syndrome and Lumbosacral radiculopathy share many of the symptoms occurring in Tarsal tunnel syndrome. Chinese and American researchers suggest that the prevalence of Tarsal tunnel syndrome is significant in patients with Lumbosacral radiculopathy. Thus, more caution should be paid when diagnosing and managing patients with lumarsacral radiculopathy due to the possible existence of Tarsal tunnel syndrome, as their management strategies are quite different.2
How Prolotherapy works
Prolotherapy is a treatment that regenerates and strengthens the injured structures, such as the weakened ligaments discussed above. Prolotherapy solution stimulates the body’s own mechanism for healing. If the metatarsal, lateral collateral and medial collateral ligaments are found to be the source of injury, then these weakened ligaments would be injected with a Prolotherapy solution triggering a localized mild inflammation. This produces a wound healing response resulting in an increased blood supply and deposits of new collagen. Ligaments are made of collagen, so those weakened ligaments that are causing the pain and other symptoms, become stronger with the new and tighter collagen. As they repair, the symptoms abate.
The tissue strengthening and pain relief stimulated by Prolotherapy is permanent. Individuals receiving Prolotherapy are also able to continue with sports, work, and other activities between treatments. Contrary to the postsurgical protocols that require extended time off of your feet; activity, walking, and movement would be encouraged.
1 McSweeney SC, Cichero M. Tarsal tunnel syndrome-A narrative literature review. Foot (Edinb). 2015 Dec;25(4):244-50. doi: 10.1016/j.foot.2015.08.008.
2. Zheng C, Zhu Y, Jiang J, Ma X, Lu F, Jin X, Weber R. The prevalence of tarsal tunnel syndrome in patients with lumbosacral radiculopathy. Eur Spine J. 2016 Mar;25(3):895-905. doi: 10.1007/s00586-015-4246-x. Epub 2015 Sep 25.