Avulsion fracture

Introduction Avulsion fracture: The internal humeral fracture of the humerus is common in sports injuries such as falling or throwing on the ground. When the forearm is stretched and abducted after the fall, the forearm flexor contraction is fierce, and the upper jaw of the humerus is pulled by the flexor muscles to cause avulsion fracture. When the elbow joint falls straight, the hand supports the ground and the upper limb is in the outreach position. The valgus stress causes the elbow joint to valgus, while the forearm flexor muscles contract suddenly, and the inner upper jaw is avulsed. The inner upper jaw is a relatively late closure of the epiphysis, and the sacral line itself is a potential weakness before it is closed. Therefore, osteophyte separation can occur

Cause

Often caused by falling or throwing sports.

When the elbow joint falls straight, the hand supports the ground, the upper limb is in the outreach position, the valgus stress causes the elbow joint to valgus, and the forearm flexor muscle group suddenly contracts, the inner upper jaw is avulsed, and the upper upper jaw is a closed comparison. Late epiphyses, the squall line itself is a potential weakness before it is closed. Therefore, the osteophyte can be separated, pulled down and forwarded, and rotated. At the same time, the medial space of the elbow joint is temporarily pulled apart, or the posterior lateral dislocation of the elbow joint occurs. The avulsed internal epicondyle (bone callus) is clamped in the joint and can be divided into 4 degrees according to the severity of the injury.

I° injury: only fractures or osteophytes are separated and the displacement is minimal.

II° injury: The bone block is displaced downwards and is rotated forward to reach the joint level.

III° injury: The fracture block is clamped in the joint and has a subluxation of the elbow joint.

IV° injury: posterior dislocation of the elbow or posterolateral dislocation, the bone is clamped in the joint.

an examination

Related inspection

X-ray examination of bone imaging

Children are more common than adults. After the injury, the soft tissue around the medial and medial epicondyles of the elbow is swollen, or a large hematoma is formed. Clinical examination of the elbow joint isose triangle relationship exists. Pain, especially local swelling of the inside of the elbow, tenderness, and disappearance of the contour of the normal internal palate. Elbow joint activity is limited, forearm pronation, flexion, and weakness. In patients with dislocation of the elbow joint, the shape of the elbow joint was significantly changed, and the dysfunction was more obvious. The symptoms of ulnar nerve injury were often combined.

In the case of avulsion fracture of the medial malleolus of the humerus, the medial tissues of the elbow joint, such as the collateral ligament, joint capsule, internal iliac crest and ulnar nerve, can be damaged. The inside of the elbow joint is swollen and painful, and localized subcutaneous can be seen as congestion. The tenderness is limited to the inside of the elbow. Sometimes it can touch the feeling of bone friction. Elbow joint flexion and rotation are limited.

Differential diagnosis

According to the history of trauma, clinical manifestations and X-ray examination, the disease can generally make a diagnosis, but for some special cases, it still needs careful identification. In particular, it is necessary to distinguish from the upper humerus in the humerus. The upper humerus of the humerus appears at about 6 to 10 years old, and is closed at the age of 18, but sometimes there may be people who are not closed. It should be distinguished from the fracture.

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