As sciatic nerve travels along the posterior compartment of leg, it branches off at certain levels to form several different tributaries. Tibial nerve is one such branch of sciatic nerve. It arises in the poplitial fossa (back side of the knee) and travels down to the posterior side of lower leg ending at the foot.
The main function of tibial nerve is to provide instructions to muscles of calf and foot.In addition it also provides sensation to the skin of lower leg and foot. An injury to the tibial nerve can compromise the function of tibial nerve. The condition is characterized by loss of sensation and movement of lower leg.
Damage to the tibial nerve is not common, but when occurs it is due to direct trauma, entrapment in the space through which it passes or due to prolonged compression.Management consists of addressing the underlying cause such as removal of pressure on entrapped nerve. Later on physical therapy will be beneficial for strengthening the function of muscles.
What Causes Tibial Nerve Damage?
Injury to the tibial nerve resulting in its dysfunction can occur from variety of reasons, although the injury is not very common. In majority of cases tibial nerve damage is associated with fracture of tibia (lower leg bone). Since the nerve is close to the tibia bone, fragments of broken bone can injure the nerve.
The tibial nerve can be damaged if it gets entrapped in the narrow space of tarsal tunnel through which it passes. Tarsal canal is located in the ankle. It is formed between medial side of ankle bone (medial malleolus) and a ligament which attaches to the foot. The nerve passes through this tunnel to provide sensation on the lower aspect of foot.
It can get compressed in the tunnel due to swelling as in case of ankle sprain. Systemic disease such as arthritis and diabetes which cause swelling can also compress the nerve. A ganglion cyst or a bone spur in this area may also lead to pressure.
Injury to the nerve can disintegrate the covering myelin sheath. Myelin sheath acts as an insulating agent for the nerve. It can also cause injury to the never cells. As a result of injury to the sheath or the cells, nerve impulses are blocked leading to its dysfunction.
Signs And Symptoms Of Tibial Nerve Injury
Injury to tibial nerve can give rise to several symptoms. Since the nerve provides sensation to the skin of foot and sole, patient may complain of changes in sensation of foot.
He may experience tingling and burning sensation at the bottom of foot and toes. It may be associated with shooting pain in the sole and foot.
As the nerve also innervates the calf and lower leg muscles, any damage of injury to the nerve can cause weakness in the lower leg, ankle and toes. Patient with weak muscles finds difficulty while walking.
Treatment For Tibial Nerve Damage
In majority of cases over a period of time treatment is not necessary as there is spontaneous recovery of the damaged nerve. However, during this period all conservative measures are taken to reduce swelling.
Patient may be recommended anti inflammatory medicines with will reduce swelling and pressure built up on the nerve. Steroid injection may be needed in the tarsal tunnel to reduce swelling and compression.
Patient is advised to limit his movement to allow healing of the injured area. Braces, splints and other orthotic devices may help to alleviate the symptoms by immobilization of the affected leg and foot.
In incurable cases, surgery may be required to release compression over the nerve in the tarsal canal. Physiotherapy exercises may be useful to strengthen the muscle tone and strength.