radial nerve injury
Introduction
Introduction to sacral nerve injury The phrenic nerve is close to the diaphysis in the lower third of the humerus. Here, the phrenic nerve is vulnerable to injury when the humerus fractures. The excessive growth of the epiphysis and the dislocation of the humeral head can compress the phrenic nerve. Inadvertent surgery can also hurt this nerve. The phrenic nerve consists of the fibers of the neck 5-8 and the thoracic 1 nerve root, which is the continuation of the posterior bundle of the brachial plexus. In the upper arm, the radial nerve exits the axillary fossa from the medial aspect of the upper arm along the deep iliac artery through the triceps head between the long head and the medial head to the back of the upper arm, and then bypasses the sacral sacral sulcus between the triceps and the lateral head. When descending to the upper side of the elbow, it is divided into two parts, shallow and deep, and then enters the forearm. The phrenic nerve branches in the upper arm, and it occupies the triceps, diaphragm, and the long extensor muscle of the temporal arm. In the forearm, the superficial branch is located deep in the diaphragm and is accompanied by the radial artery. The superficial branch is mainly the sensory nerve fiber. It is distributed on the skin of the back of the back of the hand, and the back of the two half-fingers on the temporal side, but does not include the skin on the back of the distal two sections. The deep branch, also known as the dorsal nerve of the bone, passes through the deep side of the diaphragm to the back of the forearm. After passing through the supinator muscle, it descends between the shallow and deep muscles. The muscles that branch to the branch are: the branches of the supinator The short extensor muscle and the supinator muscle of the radial side of the wrist; the dominant extensor muscle, the intrinsic extensor muscle of the little finger, the ulnar wrist extensor muscle, the long thumb muscle, and the short extensor muscle of the thumb, which are the intrinsic extensors. basic knowledge The proportion of illness: 0.02% (more common in car accidents) Susceptible people: no special people Mode of infection: non-infectious Complications: ligament injury meniscus injury
Cause
Cause of sacral nerve injury
Radial nerve injury is more common, for the following reasons:
1. Because the phrenic nerve is close to the tibia in the upper arm, it is also closer to the tibia in the forearm, so the fracture is often injured at the same time; it is often buried in the epiphysis during the fracture healing process.
2. Pulling or pressing to injure them, such as excessive abduction of the upper limbs or sleep on the upper arm of the headrest.
3. Gunshot wounds, cut wounds, and direct injuries during wartime or corner fights.
4. Surgical injury: for example, a humeral head resection or a tibial surgery.
5. Excessive growth of the epiphysis or dislocation of the humeral head can also compress the phrenic nerve.
Prevention
Radial nerve injury prevention
The sacral nerve injury often occurs in the middle and lower humerus fractures. Therefore, once patients with displaced middle and lower humeral fractures are found, regardless of whether they have radial nerve injury, it is recommended that they should not be reset by hand to avoid sacral nerve injury or aggravation of sacral nerve injury. The function of the phrenic nerve must be checked before surgery. In addition, it is necessary to pay attention to early functional exercise to restore the function of the affected limb.
Complication
Radial nerve injury complications Complications ligament injury meniscal injury
After sacral nerve injury, it can mainly cause some of the following concurrent manifestations:
1. The forearm cannot be rotated;
2, the finger can not be straight;
3. The thumb cannot be abducted.
Symptom
Symptoms of radial nerve injury Common symptoms Thumb adductor malformation sensory nerve injury Muscle atrophy Forearm pronation deformity Wrist heel drooping wrist
The disease mainly has the following two aspects of clinical manifestations:
(1) Exercise: When the upper arm sacral nerve is injured, each extensor muscle is extensively sacral, triceps, diaphragm, sacral long and short extensor muscle, supinator muscle, extension finger muscle, ulnar wrist extensor and index finger The intrinsic extensor muscle of the little finger is uniform, so the wrist is drooping, the thumb and each finger are drooping, the knuckle can not be extended, the forearm has a pronation deformity, and the thumb cannot be rotated, and the thumb is deformed.
When examining the triceps and the extension of the wrist muscle, it should be carried out in the direction of anti-gravity, the thumb loses its abduction, can not stabilize the metacarpophalangeal joint, and the thumb function is severely impaired, because the length of the ulnar wrist extensor and the temporal extension of the wrist Tendons, the wrists are difficult to move to the sides, the dorsal muscles of the forearms are atrophied, and the dorsal nerves in the dorsal forearm are mostly interosseous nerve injury. The sensation and triceps muscles are not affected. The long extensor muscles are good, and the other extensors are even.
(2) Feeling: After the sacral nerve injury, the back of the hand is half-shouldered, the two sides of the sacral side are half-finger, and the upper arm and the forearm are sensation at the back.
Examine
Examination of radial nerve injury
There is no relevant laboratory examination, the disease is mainly for routine physical examination, the most common is neuro-electromyography:
The single-issue impulse of motor neurons can cause synchronous contraction of all muscle fibers dominated by axons. The recorded potential is MU P. Normally, nerve impulses synchronously discharge all muscle fibers of one motor unit, producing a MU. P; but this is not the case in denervated muscle fibers. After 2 weeks, the denervated muscle fibers increase the sensitivity to acetylcholine, which is 100 times normal. They spontaneously release the potential, that is, fibrillation. Potential, electroencephalography has important diagnostic value for peripheral nerve injury. Electromyography abnormalities can only prove neurogenic damage, while electroencephalogram changes make lesion localization more obvious. MCV is sensitive to peripheral nerve trauma. Sports fiber coarse fiber is susceptible to injury.
Defining the nature of the damage according to the neuroelectromyogram:
1 Complete damage: There are self-generating activities, no MU P, CMA P, SNA P, MNCV disappear;
2 Severe damage: There is self-generating activity, no MU P, CMA P amplitude decreases, SNA P decreases or disappears, MNCV slows down or disappears;
3 Incomplete damage: There may be self-generating activity or insertion potential extension, MU P decreases, CMA P decreases, SNA P decreases, and MNCV is normal or slow.
Diagnosis
Diagnosis and diagnosis of radial nerve injury
Diagnose based on
1. Have a history of trauma.
2. Those with complete injuries above the elbow, can not stretch the wrist, stretch the thumb, stretch the fingers and the abduction of the thumb, showing a deformed wrist, and the hand is at the mouth of the tiger.
3. Those who have complete injuries below the elbow, have no effect, can't stretch the thumb, show the thumb and reach out, and have no wrist deformity.
4. EMG examination is helpful for diagnosis.
The diagnosis of this disease needs to be identified with the following two diseases:
1. Ulnar nerve injury: After the ulnar nerve injury, in addition to the sensation disappeared on the ulnar side of the hand, the ring, the little finger metacarpophalangeal joint is overextended, the interphalangeal joint flexes in a claw shape, the thumb cannot be adducted, and the other four fingers cannot be abducted. Adduction.
2, median nerve injury: humeral supracondylar fracture can cause the median nerve crush injury, fracture can often recover after the reduction, the thumb can appear after injury, the middle finger can not flex, the thumb can not abduction and palm, palm sputum Three side and half fingers on the side felt the obstacle.
