humeral head fracture
Introduction
Brief introduction of humeral head fracture A small head fracture of the humerus is a rare elbow injury, accounting for about 0.5% to 1% of the elbow fracture. In adults, simple humeral head fractures occur in children, and children with small humeral head fractures with partial external malleolus fractures may occur. The fracture is easily misdiagnosed as a lateral or external iliac fracture. basic knowledge The proportion of illness: 1% Susceptible people: no specific population Mode of infection: non-infectious Complications: elbow joint stiffness and fibrous stiffness
Cause
Causes of humeral head fracture
(1) Causes of the disease
The disease is caused by the scissor stress, that is, when the elbow joint is straight, the valgus falls and the hand touches the ground, and the external force is transmitted along the tibia to the elbow. The humeral head hits the humeral head upward, and the valgus stress can cause The medial soft tissue injury is classified into the following three types according to the extent of the injury and the extent of the fracture.
1. Complete fracture (Hahn-Steinthal fracture) is the coronal fracture of the base of the humeral head. The fracture block itself includes all the humeral head and 1/3 or 1/2 of the lateral part of the trochle, but sometimes it is limited to the humeral head itself.
2, partial fracture (Kocher-Lorenz fracture) fracture block only contains the small head of the humerus, articular cartilage and a small amount of bone below it.
3, humeral head articular cartilage contusion injury caused by insufficient external force to cause fractures, only caused by contusion of the humeral head joints, X-ray can not be shown, not easy to diagnose, in the late surgery for humeral head resection and other methods, can be found in cartilage damage.
(two) pathogenesis
Mostly caused by indirect violence, the small head of the humerus is located at the temporal side of the lower end of the humerus, a round and smooth nodule that protrudes forward. When the elbow joint is flexed, the small head of the humerus rotates on the anterior joint surface; after extreme flexion of the elbow, The edge of the humeral head is just inside the humeral head socket above the small head of the humerus; when it is straight, the humeral head rotates under the articular surface of the humeral head. After the fall, the elbow joint is slightly flexed, and the external force is transmitted along the tibia to the elbow. The head moves like the piston of the internal combustion engine, and the small head of the humerus is hit.
Prevention
Prevention of humeral head fracture
Prevention of this disease should pay attention to the labor intensity should not be too large, do not walk heavy objects for a long time, every time you wash clothes should not be too much, prevent the upper iliac muscle fascia strain of the humerus, usually pay attention to exercise, active upper limb joints, enhance Muscle strength helps prevent the disease from happening.
Complication
Complications of humeral head fracture Complications elbow joint stiffness and fibrous stiffness
The disease can cause elbow joint stiffness, dysfunction, small range of joint activity; in some cases, combined with medial ligament injury, etc., humeral head fracture is an intra-articular injury, such as failure to timely diagnosis, delay treatment, joint function Greater impact.
Symptom
Symptoms of humeral head fracture Common symptoms Elbow severe pain,... Elbow joint can not flex the elbow swelling, tenderness, comminuted fracture
The back of the elbow is swollen in the joint, so the performance is not obvious, but there is obvious activity limitation and tenderness of the small head of the humerus. If the medial ligament injury is combined, there is an increase in tenderness and valgus activity. After the injury, the elbow Swelling and pain, swelling occurs in the lateral side of the elbow and the elbow. The pain and tenderness are limited to the lateral side of the elbow or the anterior elbow. The flexion and extension of the elbow is limited. Especially when the flexion is 90°-100°, the elbow often occurs. The pain is aggravated and there is a feeling of resistance (Figure 1).
Type I complete fracture (Hahn-Steinthal fracture), fracture block including the humeral head and part of the trochlear.
Type II simple humeral head fracture (Kocher-Lorenz fracture), sometimes difficult to find on X-ray films due to small fractures.
Type III comminuted fracture, or humeral head and trochlear fracture and separation.
Type IV humeral head joint cartilage injury.
Examine
Examination of humeral head fracture
There is no relevant laboratory examination, and the auxiliary examination method for this disease is mainly X-ray examination:
X-ray findings are often characteristic. The anterior and posterior X-ray films are helpful in judging the size of the combined trochlear fracture block, but only the lateral X-ray film can reflect the characteristics of this damage. The typical performance is the appearance of "double arc sign". However, if the lateral X-ray film is slightly inclined, the distal end of the humerus will cover the fracture block, leading to missed diagnosis. The X-ray film of the lateral position must be carefully observed before the diagnosis can be confirmed. Because the bone block contains articular cartilage, the X-ray The film can not reflect its true size. The actual fracture piece is much larger than the image displayed by the X-ray film. Some of the humeral head and the trochlear are fractured at the same time. If the fracture piece is displaced and the lower end of the humerus overlaps, it is easy to neglect the diagnosis. Scanning and three-dimensional structural reconstruction to confirm the diagnosis.
Diagnosis
Diagnosis and diagnosis of humeral head fracture
diagnosis
Traumatic history, after the injury, the elbows are swollen and the pain is obvious. It usually occurs in the lateral side of the elbow and the elbow. The pain and tenderness are also on the lateral side of the elbow or the anterior elbow. The flexion and extension of the elbow is limited, especially 90°~100. When the elbow pain is aggravated and there is a sense of resistance, X-ray examination can show fracture and classification.
Pay attention to the following issues when diagnosing:
(1) Changes in several ossification centers in normal children's elbow joints. The sacral sacral sacral center appears approximately 10 months after birth, and the entire elbow is completely ossified at about 13 years. During this period, the elbow The appearance of ossification center and the order of ossification are the humeral head, the humeral head, the upper iliac crest, the trochle, the olecranon, and the upper iliac crest. The age of the epiphysis and the joint age should be memorized, and the main ossification centers of the elbow should be known. The morphology of the child is very important, avoiding the normal ossification center as a fracture block, the osteophytes have complete edges, the fracture fragments are irregular and the adjacent bones are defective.
(2) The morphological changes and position changes of the humeral head on the X-ray. The normal pediatric sacral skull-skullization center is on the anteroposterior plane. It is located on the inner side of the tibia and the humeral head, and has a guar-like tip facing inward. Position, when the current arm is straight, the upper end of the ulna overlaps with the inner part of the small head. On the lateral piece, the small skull of the humerus is located in front of the lower end of the humerus, and a line is drawn along the front edge of the humerus, and a parallel line is drawn through the central axis of the humerus. Before the age of 9 years, after the front of the sacral skull degeneration center, after 9 years old, 2/3 of the small head is located before the front line, and the entire epiphysis is still in front of the back line.
(3) The change of relationship is generally based on the above positional relationship to determine whether there is displacement of the humeral head, but the elbow joint activity is limited due to elbow injury, and the child does not cooperate, it is difficult to get the standard as required. Positioning piece, at this time, the position of the humeral head can be judged by the sputum relationship. Regardless of any position of the elbow joint, the longitudinal axis of the humeral shaft center point must pass through the center point of the humeral head, if the humerus small skull If the center point does not pass through this longitudinal axis, it indicates that the ankle joint relationship has changed.
Differential diagnosis
Diagnosis of humeral head fractures is often confused with humeral external malleolus fractures. The identification of the two is particularly important. The treatment is also very different. The humeral external malleolus fracture often causes instability of the ulnar joint. The humeral head fracture only affects the articular surface and forms an intra-articular joint. The bone piece, but the stability of the elbow joint can still be maintained. In addition, the disease needs to be differentiated from the humeral shaft fracture, X-ray examination can be identified.
