What Are the Nerves of the Leg?

The main nerves of the lower limbs are the sciatic nerve, the tibial nerve and the common peroneal nerve. Sciatic nerve injury is more common when the hip is dislocated posteriorly, showing paralysis of the knee flexor muscles, calf and foot muscles, and loss of sensation on the back of the thigh, the outside of the calf, and the foot. Tibial nerve injury is seen when the femoral condyle fractures and knee dislocations cause paralysis of the gastrocnemius, soleus, flexor and plantar muscles, and loss of foot sensation. Common peroneal nerve injury is seen when the fibula head or fibula neck is fractured, which causes paralysis of the calf extensors, peroneus longus, and sagging feet. Lower limb nerve injury should be explored as soon as possible.

Chinese name: Lower limb nerve injury

Foreign name: lower Extremity nerve trauma

Causes of lower limb nerve injury and common diseases

1 Lower extremity nerve injury 1, femoral nerve injury is relatively rare

Possible causes are: hematoma in the posterior wall of the abdomen, abdomen muscle abscess, tumor in the popliteal cavity compressing the femoral nerve, femoral trauma and fracture of the superior branch of the pubic bone, hernia repair, surgery of the great saphenous vein and accidental injury to the femoral and saphenous nerve . The femoral nerve is the largest branch of the lumbar plexus, and its innervation area: the branches in the iliac fossa dominate the diaphragm and psoas muscle; after reaching the inguinal ligament, it is divided into many muscle branches and dermal branches that dominate the pubic muscle, the sartorius muscle, and the femur. Quadriceps, muscles around the knee joint, and skin of the medial anterior femur.

2 Lower extremity nerve injury 2, sciatic nerve injury

The sciatic nerve is the largest nerve in the body and comes from the lumbosacral plexus nerve. It exits the pelvis at the sciatic notch and enters the hip. Down to the lower third of the thigh is divided into the tibial nerve and the common peroneal nerve. Therefore, damage to the sciatic nerve trunk is far rarer than damage to its terminal branches. Lumbar disc herniation, spine fractures and dislocations can compress and damage the sciatic nerve root. Improper hip injection sites, hip dislocations, femoral shaft fractures, fractures of the sacrum and sacrum can damage the sciatic nerve. Common peroneal nerve injury is most common in lower extremity nerve injury. Visible in the fibula head or fibula neck fractures, calf fixation of the calf too tight, posterior fossa cut injury, tibiofibular joint dislocation and so on. Fracture of the femoral condyle and dislocation of the knee joint are common causes of injury to the tibial nerve.

Differential diagnosis of lower limb nerve injury

1 Lower extremity nerve injury 1, femoral nerve injury

Quadriceps paralysis due to weakness of the lower leg extension and flexion of the thigh, can not climb the steps and jump, easily fall, quadriceps atrophy, knee reflex disappeared, anterior femoral and calf sensory disturbance.

2 Lower extremity nerve injury 2, sciatic nerve injury

(1) Sciatic Nerve Injury

Post-injury performance depends on the level of injury. When the injury site is high, all the muscles in the back of the thigh, the calf, and the foot are paralyzed, and the knee joint cannot be flexed, and the ankle and toe movements completely disappear. Due to the sound quadriceps muscles, the knee joint was in a straight state, and it showed a "crossing gait" when walking. Achilles tendon reflexes disappear, sensations or pain appear on the outside of the calf, and loss of superficial sensation of the foot often results in injuries and ulcers. If the middle and lower part of the femur is injured, the hamstring muscle is normal, and the knee flexion function is preserved.

(2) Tibial nerve injury

After the tibial nerve injury, paralysis and paralysis of the posterior flexor muscles of the calf and the muscles of the soles of the feet occurs, and the sensation of the feet disappears. Plantar pressure ulcers or neuroulcers can occur. Manifestations of plantar flexion, foot adduction and varus are difficult, erect foot, can not flexion of toes, loss of elasticity and strength of the arch, weight loss of the lower leg. Achilles tendon reflexes disappeared due to anterior tibial contracture and excessive ankle extension. If the injury site is below the gastrocnemius and longus flexor branches, only toe dyskinesia and plantar dysfunction appear. When the tibial nerve is partially injured, burning neuralgia often occurs, accompanied by sweating and nutritional disorders.

(3) Common peroneal nerve injury

The common peroneal nerve is susceptible to damage in the ministry and fibula, leading to paralysis of the anterolateral extensor muscles of the calf, dorsiflexion and valgus dysfunction, manifesting foot drop and turning to the inside to become a horseshoe instep; It is in a flexed state; it is "across gait" when walking. Sensational disturbances in the anterior lateral of the calf and the back of the foot, pain is rare. Dyskinesias are more severe than sensory disorders.

Lower Extremity Nerve Injury Examination

When high-frequency ultrasound is used to examine the nerves of the lower extremity, not only the continuity, thickness and internal echo of the nerve itself, but also the changes of the injured nerve and surrounding tissues should be carefully observed. Compression and the presence or absence of scar tissue, etc. By observing the surrounding tissues such as muscles, tendons, and blood vessels at the site of the injury, the accidental injury to the surrounding tissue is reduced, which avoids iatrogenic damage to the nerve and shortens the operation time. Understanding the patient's medical history and signs is also essential for high-frequency ultrasound examination of nerve damage and lesions.

Principles of lower limb nerve injury treatment

The treatment principle of lower limb nerve injury is to strengthen blood circulation, enhance the metabolism of injured tissues, improve the excitability of nerve cells and tissues, and promote the functional recovery of affected limbs.

Those who cannot recover after 1 to 2 years of active treatment should consider joint fusion to stabilize the joints. If it is a nerve rupture, it should be repaired as soon as possible.