| disease | Elbow Dislocation |
Elbow dislocation accounts for half of the total dislocations of the four major joints in the body. The lower end of the humerus, which forms the elbow joint, is wide and thick on the sides but thin and flat front-to-back. The sides are protected by strong ligaments, while the front and back of the joint capsule are relatively weak. The primary movements of the elbow joint are flexion and extension. The coronoid process of the ulna is smaller than the olecranon process, making the joint less resistant to backward movement than forward movement. As a result, posterior dislocation of the elbow joint is far more common than dislocations in other directions. If a fresh dislocation is correctly diagnosed and properly treated during the advanced menstrual period, it will not result in significant functional impairment. However, if early intervention is delayed or incorrect, it may lead to severe functional impairment in the advanced stage. At this point, no matter how meticulous the treatment, normal function cannot be fully restored, and only varying degrees of functional improvement can be achieved.
bubble_chart Etiology
Posterior dislocation of the elbow joint is the most common type, predominantly occurring in young adults, caused by transmitted force and leverage. When falling and bracing with the hand, the joint is in a semi-extended position, and the force is transmitted upward along the long axis of the ulna and radius, driving the proximal ends of the ulna and radius upward and backward. When the transmitted force hyperextends the elbow joint, the olecranon impacts the olecranon fossa at the distal end of the humerus, creating a powerful leverage effect that tears the brachialis muscle attached to the coronoid process and the anterior joint capsule. The distal end of the humerus continues to move forward while the olecranon shifts backward, resulting in posterior dislocation of the elbow joint. Depending on the direction of the force, the olecranon may also shift medially or laterally in addition to moving backward. Some cases may involve a concomitant coronoid process fracture. The brachialis muscle may be avulsed, leading to hematoma formation. Elbow dislocation can be accompanied by a fracture of the medial epicondyle of the humerus, and sometimes the fractured fragment may become lodged in the joint, hindering reduction. Ulnar nerve injury may also occur.
bubble_chart Clinical Manifestations1. Special manifestations of dislocation The elbow shows obvious deformity, with fullness in the cubital fossa, shortening of the forearm's appearance, posterior protrusion of the olecranon, and emptiness and depression in the posterior elbow. The joint is elastically fixed at 120-140 degrees, with only minimal passive mobility. The normal bony landmarks of the elbow are altered: in a normal extended elbow, the olecranon and the medial and lateral epicondyles of the humerus form a straight line; during flexion, they form an isosceles triangle. In dislocation, these relationships are disrupted. In supracondylar fractures of the humerus, the triangular relationship remains normal—this is a key feature for distinguishing between the two.
2. Complications of elbow dislocation Posterior dislocation may sometimes be accompanied by ulnar nerve injury or other nerve injuries, as well as fractures of the coronoid process of the ulna. Anterior dislocation is often associated with fractures of the olecranon of the ulna, among others.
3. X-ray examination Anteroposterior and lateral views of the elbow joint can reveal the type of dislocation, any associated fractures, and help differentiate it from supracondylar fractures. {|102|}
There is a history of trauma, most commonly from falling and landing on the palm. The affected area is swollen, painful, and immobile. The patient supports the affected forearm with the healthy hand, with the elbow joint in a semi-extended position. Passive movement reveals an inability to fully extend the elbow. A hollow sensation is felt at the back of the elbow, and a depression can be palpated. The normal three-point relationship of the elbow is completely disrupted and lost. Diagnosis can be confirmed by X-ray examination.
bubble_chart Treatment Measures
1. Fresh posterior dislocation of the elbow joint
Manual reduction is commonly performed using the traction reduction method. Under brachial plexus anesthesia, the surgeon holds the injured forearm in supination to relax the biceps brachii before applying traction, while an assistant provides counter-traction. First, correct the lateral displacement, then continue traction while flexing the elbow joint and slightly pushing the humerus backward. A clicking sound may be felt upon reduction. If successful, joint movement and bony landmarks will return to normal. For solo operation, the knee-elbow reduction method or chair-back reduction method can be used.
Post-reduction management: After reduction, immobilize the elbow at 90° flexion with a cast or splint for 3–4 weeks. Remove the fixation afterward and gradually encourage active joint movement. Avoid passive stretching to prevent myositis ossificans.
For elbow dislocation combined with humerus internal epicondyle fracture or radial head fracture, surgical reduction is indicated if manual reduction fails. In adults, radial head excision may be performed.
2. Old dislocation
For old elbow dislocations within three months of injury, manual reduction may be attempted. If unsuccessful, forceful reduction should be avoided, and surgical reduction is necessary. If ulnar nerve injury is present, explore the nerve first during surgery and protect it during reduction. Post-reduction, consider transposing the ulnar nerve anteriorly. If articular cartilage is damaged, elbow arthroplasty or artificial joint replacement may be considered.
3. Anterior dislocation of the elbow joint
For manual reduction, position the elbow in high flexion. An assistant pulls the upper arm while the surgeon holds the forearm and pushes it backward to achieve reduction. Post-reduction, immobilize in semi-extension for four weeks. If the olecranon cannot be reduced manually, surgical reduction and fixation are required.
humerus supracondylar fracture
