Monteggia fracture

Introduction to Monteggia Fracture Monteggiafracture refers to the proximal 1/3 fracture of the ulna and the dislocation of the humeral head. It was first described by Monteggia in 1814, and the fracture was dislocated under its name. It is characterized by swelling of the elbow and forearm after trauma, and obvious dislocation can be seen in the ulnar horn or depression. The humeral head can be touched out before or after the elbow joint. Forearm rotation is limited. Severe swelling is unclear, local tenderness is obvious. basic knowledge The proportion of illness: 0.002% Susceptible people: no special people Mode of infection: non-infectious Complications: radial nerve injury

Cause of Monteggia fracture

Violence factor (98%):

Mostly direct violence, caused by the violence. The elbow joint falls straight or overstretched, and the forearm spins the palm to touch the ground. The force is transmitted to the anterior humerus, causing oblique fracture of the ulna. The residual violence is transferred to the upper end of the humerus, forcing the humeral head to break through and slide out of the annular ligament, dislocate to the front and the outer side, and the fracture end is formed to the volar and temporal sides. angle. Adult direct violence strikes a fracture, and the fracture is transverse or comminuted.

Pathogenesis:

Most scholars believe that type I fractures are caused by pre-rotation violence or direct blows on the dorsal side of the ulna.

In 1949, Evans experimented on a corpse. In the case of a fixed tibia, a strong pronation of the forearm caused a anterior dislocation of the humerus and a fracture of the ulna. Evans pointed out that the hand and forearm are usually in a fully pre-rotation position when the fall, when the hand is fixed to the ground. The weight of the upper extremity is externally rotated, which causes the extreme pronation of the forearm and the Monteggia fracture. Another evidence from Bado is that the type I fracture is on the dorsal side of the elbow. In the pronator position, at the same time, a certain number of type I fractures can be seen in the clinic without a history of falls, but directly hit the back of the ulnar when playing baseball or softball.

In summary, type I fractures can be caused by falls, forearm extreme pronation, or by direct impact on the dorsal ulna.

The injury mechanism of type IV fractures is considered by most to be the same as type I fractures, so a fracture of the tibia may be caused by two injuries after dislocation of the humeral head.

Penrose (1951) described the injury mechanism of type II fractures, which he believes is similar to the posterior dislocation of the elbow joint, but this type of ulnar ligament is more tough than the ulnar bone, thus the elbow falls and the hand Conductive violence while supporting the ground caused dislocation of the humeral head and fracture of the ulna, while the ulnar and ankle joints remained intact.

Bado believes that the damage mechanism of type III fractures is caused by direct impact on the inner side of the elbow. It is caused by collisions and is only seen in children.

Monteggia fracture prevention

Avoid trauma. Keep your mood steady and avoid emotional excitement and tension. Adjust daily life and workload, and regularly carry out activities and exercise to avoid fatigue. Avoid cold irritation and keep warm. Keep the stool smooth, avoid using stools, eat more fruits and high-fiber foods.

Monteggia fracture complications Complications, radial nerve injury

Often accompanied by deep sacral nerve injury and extension of the cavity, extension finger dysfunction.

Common symptoms of Monteggia fracture Common symptoms Elbow joint dislocation of the forearm has pre-rotation deformity in the wrist joint and ... joint pain elbow severe pain, ... forearm shortening forearm rotation pain

1. General symptoms refer to local pain after fracture, common symptoms such as swelling and limited mobility are more obvious.

2. The deformed ulna is superficial, easy to find displacement, and the dislocation of the humeral head is easy to be detected, but it is difficult to determine the swelling.

3. Touching the humeral head is in front of or on the side of the elbow. The humeral head of the bulge can be touched at the back, accompanied by rotational pain and limited mobility. When the humeral head is dislocated, it is often injured and the deep branch of the radial nerve.

The most widely used clinically is the type 4 summarized by Bado (1967).

Type I: About 60%, is a fracture of any level of the ulna, which is angled forward and combined with dislocation of the humeral head.

Type II: About 15%, it is a ulnar shaft fracture, and it is angled to the posterior side (dorsal side) with posterior dislocation of the humeral head.

Type III: about 20%, is a proximal metaphyseal fracture of the ulna, combined with dislocation of the humeral head to the lateral or anterior side, only found in children, also known as children.

Type IV: About 5%, for anterior dislocation of the humerus, nearly 1/3 of the humerus fracture, and any level of fracture of the ulna.

Monteggia fracture examination

The laboratory examination of the disease is mainly X-ray examination: the forearm positive and lateral slices can be diagnosed. The elbow joint should be included to avoid missed diagnosis, pay attention to the anatomic relationship of the ankle joint, and if necessary, take a healthy side X-ray film for comparison. In the upper segment of the ulna, and the X-ray film did not see the dislocation of the humeral head, it should be noted whether it is self-resetting after dislocation of the humeral head.

Diagnosis and diagnosis of Monteggia fracture

Clear history of trauma, pain and tenderness, and clear X-ray films, no difficulty in diagnosis, only in children can not accurately describe the history of trauma and accurate pain, so clinical examination and X-ray film is very important, children's elbow The X-ray anatomical relationship is judged according to the corresponding position of the osteophytes at the joint end. Under normal conditions, the longitudinal axis of the humeral head extends through the center of the humeral head. Otherwise, the humeral head is dislocated. The ulnar shaft and the proximal ulna should be observed. No fractures, the same, such as ulnar fractures, should pay attention to the humeral head with or without dislocation, if necessary, plus the contralateral elbow X-ray film compared with this, in children, Monteggia fracture Another feature is that ulnar fracture can occur in the backbone The upper third, but there are quite a few cases in the proximal ulnar olecranon, the fracture can be longitudinal and transverse cleft palate, or the cortex is wrinkled, this special performance may be related to the characteristics of children's bone structure, when When the child falls and is injured, the ulnar shaft is more elastic and does not fracture, and the olecranon is directly cleft by the impact of the lower end of the humerus.

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