Radial Nerve Injury

　　The radial nerve injury is relatively common, it controls the movement of many muscles, such as triceps brachii, brachioradialis, extensor carpi radialis longus, supinator, extensor digitorum communis, etc. When the radial nerve is injured, many serious problems such as finger paralysis may occur. Then, what are the causes of radial nerve injury?

　　1. Since the radial nerve is close to the humerus in the upper arm and relatively close to the radius in the forearm, it is often injured simultaneously during fractures, and it is often buried in the callus during the healing process of the fracture.

　　2. Injury due to traction or compression. For example, prolonged abduction of the upper limb or sleeping with the head on the upper arm.

　　5. Gunshot wounds, incisions. Directly injured during war or wrestling.

　　4. Surgical injury, such as radial head resection or humerus surgery resulting in injury.

　　Overgrowth of callus or radial head dislocation can also compress the radial nerve.

　　Since the radial nerve controls many muscle groups, when the radial nerve is injured, the movement function of the related muscles controlled by it will be impaired, with the external manifestation of movement obstruction in the upper limb, specifically manifested in the following three points:

　　1, The forearm cannot be pronated

　　2, The fingers cannot be extended

　　3, The thumb cannot be abducted

　　Since the radial nerve controls the contraction and relaxation of many muscles, when radial nerve injury occurs, it will cause movement disorders in the corresponding muscle groups, and the specific manifestations are as follows:

　　1, Movement

　　When the radial nerve is injured in the upper arm, all extensor muscles are widely paralyzed, including the triceps brachii, brachioradialis, radial long extensor muscle, supinator, total extensor muscle, ulnar extensor muscle, and intrinsic extensor muscles of the index and little fingers. Therefore, there is wrist drop, thumb and fingers drop, unable to extend the metacarpophalangeal joint, the forearm has a supination deformity, cannot be pronated, and the thumb has an adduction deformity.

　　When examining the triceps brachii and wrist extensor muscles, they should be performed in the opposite direction of the Earth's gravity. The thumb loses the function of abduction, cannot stabilize the metacarpophalangeal joint, and has severe dysfunction. Because the extensor carpi ulnaris and the radial extensor muscles are paralyzed, it is difficult to move the wrist to both sides. The muscles on the dorsal side of the forearm are significantly atrophied. Most of the radial nerve injuries on the dorsal side of the forearm are interosseous dorsal nerve injuries, with no effect on sensation and triceps brachii, and the radial long extensor muscle is good. Other extensor muscles are paralyzed.

　　2, Sensation

　　After radial nerve injury, there is sensory disturbance in the radial side of the back of the hand, the two radial half fingers, the upper arm, and the posterior part of the forearm.

　　Radial nerve injury often occurs in fractures of the middle and lower segments of the humerus. Therefore, once a patient with displaced fractures of the middle and lower segments of the humerus is found, whether or not accompanied by radial nerve injury, it is recommended to avoid manual reduction as much as possible to prevent or worsen radial nerve injury, which may cause difficulties in later treatment; at the same time, it is necessary to check the function of the radial nerve before surgery, and then formulate the corresponding surgical plan according to the degree of radial nerve damage, so as to minimize the damage to the radial nerve.

　　Radial nerve injury is relatively common, and the main method for diagnosing radial nerve injury is to perform routine physical examination. The most common is electromyography examination.

　　Electromyography (EMG) is a common examination item. A single discharge impulse of a motor neuron can cause synchronous contraction of all the muscle fibers it支配支配, and the recorded potential is called MUP. Normally, nerve impulses cause all the muscle fibers of a motor unit to discharge synchronously, producing a MUP. However, in denervated muscle fibers, it is not the same. After 2 weeks of denervation, the sensitivity of denervated muscle fibers to acetylcholine increases, reaching 100 times the normal level. They will spontaneously discharge potentials, that is, fibrillation potentials. Electromyography has important diagnostic value for peripheral nerve injuries. Abnormalities in electromyography can only prove neurogenic damage, while changes in electromyography make the localization of damage more obvious. MCV is very sensitive to peripheral nerve injuries, and is related to the easy injury of motor fibers. Through electromyography examination, we can determine the degree of injury.

　　1, Complete Injury

　　There is spontaneous activity, no MUP, CMAP, SNAP, and MNCV all disappear.

　　2, Severe Injury

　　There is spontaneous activity, no MUP, CMAP amplitude decrease, SNAP decrease or disappearance, MNCV slowing or disappearance.

　　3, Incomplete Injury

　　There is spontaneous activity or prolonged insertion potential, MUP reduction, CMAP decrease, SNAP decrease, MNCV normal or slowed.

　　Diet plays a significant role in the treatment of radial nerve injury. If the diet is not appropriate, it can affect the speed of recovery from the disease. So, how should radial nerve injury patients eat to recover faster?

　　1, Supplement nutrition by eating more vitamin-rich foods.

　　2, Eat more oatmeal.

　　3, Consume pure natural royal jelly. It is also beneficial to drink pure natural royal jelly in daily life, which can enhance the body's immunity and help with the recovery of the condition. Sweet foods can play a role in tonifying, harmonizing, and alleviating urgency. Eat less cold and cool foods and more warming foods: for example, mustard greens, mung beans, kelp, laver, pak choi, cabbage, cauliflower, watermelon, bitter melon, and winter melon are all cold and cool foods, and patients should avoid eating them as much as possible.

　　Closed fractures of the humerus with radial nerve injury are mostly nerve contusions, less common are avulsion injuries, and conservative treatment is usually performed first, followed by surgical exploration if ineffective. The exploration includes the exposure of the radial nerve in the axilla and upper arm, and the radial nerve in the elbow and forearm. Appropriate nerve surgery is performed according to the nature of the nerve lesion seen during surgery.

　　According to the condition of the injury, nerve decompression, release, or suture can be adopted. If necessary, methods such as flexing the elbow, internal adduction of the shoulder, and anterior displacement of the nerve can be used to overcome defects. If there are many defects, nerve transplantation surgery should be performed. The effect after nerve anastomosis is better than that of the median nerve and the ulnar nerve.

　　If the nerves cannot be repaired, a transfer of the flexor muscle tendons to the extensors for functional reconstruction can be performed, with good results. Paralysis of the triceps brachii is not very serious, as the relaxation of the flexor muscles and gravity can straighten the elbow joint.

　　Before the nerves recover, a吊带弹簧夹板 can be used to reduce overstretching of the extensors, affecting the efficacy.