Elbow dislocation

Introduction to elbow dislocation Dislocation of the elbow joint accounts for half of the total dislocation of the four major joints. The lower end of the humerus, which constitutes the elbow joint, is thick and wide inside and outside, and is thin and flat before and after. The lateral side has strong ligament protection, and the front and back of the joint capsule are quite weak. The movement of the elbow joint is mainly flexion and extension, and the ulnar coronoid process is smaller than the olecranon. Therefore, the ability to move backwards against the ulna is less than the ability to move forward. Therefore, dislocation of the ankle joint is far more common than dislocation in other directions. After the early diagnosis and proper treatment of the fresh dislocation, there will be no obvious dysfunction. Failure to get timely and correct treatment in the early stages may lead to severe dysfunction in the late stage. basic knowledge Sickness ratio: 2% Susceptible people: no specific population Mode of infection: non-infectious Complications: vascular injury elbow dislocation ossifying myositis traumatic arthritis

Cause of dislocation of elbow joint

Dislocation of the elbow joint (30%):

This is the most common type of dislocation, with adolescents as the main target. When falling, the palm of the hand touches the ground, the elbow joint is fully extended, the forearm is rotated, and the elbow joint is overextended due to human gravity and ground reaction force. The ulna olecranon The top of the tibia violently impacts the olecranon fossa at the lower end of the tibia, which forms the fulcrum of the force. The external force continues to strengthen the anterior part of the tibialis anterior and elbow joint capsules that are attached to the condyle, causing the olecranon to shift backward. The elbow joint displaced at the lower end of the humerus was dislocated.

Because the inner and outer humerus of the lower end of the humerus forming the elbow joint is wide and thick, the front and back are flat and thin, and the collateral ligament is strengthened on the side. However, if the lateral dislocation occurs, the internal and external avulsion fractures are easy to occur.

Dislocation of the elbow joint (30%):

The former dislocation is rare, and often combined with the olecranon fracture, the cause of the damage is mostly direct violence, such as direct impact on the elbow or the impact of the elbow on the ground in the flexion position, resulting in ulnar olecranon fracture and proximal ulnar dislocation This kind of damage to the soft tissue of the elbow is more serious.

Lateral dislocation of the elbow joint (20%):

It is more common in adolescents. When the elbow is subjected to conduction violence, the elbow joint is in varus or valgus, causing the collateral ligament and joint capsule of the elbow joint to tear. The lower end of the tibia can be moved to the temporal or ulnar side (ie Dislocation of the joint capsule rupture, due to strong internal and external valgus, due to the violent contraction of the forearm extension or flexor muscle group, the axillary fracture of the humerus and the external malleolus is more likely to occur, especially the fracture of the humerus. Can be embedded in the joint space.

Dislocation and dislocation of the elbow joint (10%):

This type of dislocation is extremely rare. When the upper and lower conduction violence is concentrated on the elbow joint, the forearm is excessively pronation, and the annular ligament and the proximal interosseous membrane of the ulna and radius are cleft, causing the humeral head to dislocate forward. The proximal end of the ulna is dislocated backward, and the lower end of the humerus is inserted between the ends of the two bones.

Prevention of elbow dislocation

Dislocation of the elbow joint is caused by traumatic factors. There is no special precautionary measure. Paying attention to production and life safety and avoiding trauma is the key. In addition, patients with dislocation of the elbow should move the joint early, and then the main action is extended and fixed. Forearm rotation activity or supplemented with physical therapy, but excessive forced pull, prone to ossifying myositis around the elbow joint, so it is necessary to perform functional exercise in strict accordance with the doctor's advice, so that the affected limb can restore function as soon as possible.

Complications of elbow dislocation Complications vascular injury elbow dislocation ossifying myositis traumatic arthritis

Posterior dislocation sometimes combined with ulnar nerve injury and other nerve injuries, ulnar condyle fracture, anterior dislocation with olecranon fracture.

First, early complications of joint dislocation:

When the patient is injured, the muscles attached to the lateral malleolus of the humerus contract, the joint capsule is ruptured, and combined with direct external force, can cause avulsion fracture of the lateral malleolus. Due to the inward and lateral dislocation, the displacement of the ulnar nerve and surrounding tissue Avulsion, displacement inward or outward, can cause ulnar nerve traction injury, and can also be combined with vascular injury, so fractures, nerve damage, vascular injury, infection is a common early complication of elbow dislocation, also Volkmann ischemic contracture can be concurrently performed.

Second, the late complications of joint dislocation:

Late complications are mostly caused by patients who are not treated or treated improperly, including joint stiffness, avascular necrosis of the bone, ossifying myositis, and traumatic arthritis.

Elbow joint dislocation symptoms Common symptoms Nerve injury elbow joint extension position... Elbow joint dislocation joint effusion elbow joint deformity elbow lateral night pain

The elbow is obviously deformed, the elbow is full, the forearm is short, the ulnar olecranon is protruding, the elbow is emptied and dent, and the joint elasticity is fixed at 120-140 degrees. There is only a slight passive activity, and the posterior elbow is marked. Change, under normal circumstances, when the elbow is in a straight position, the ulna olecranon and the humerus are in a straight line at three points on the outer iliac crest, and an isosceles triangle when the elbow is bent. When the dislocation is broken, the above relationship is destroyed. The triangular relationship remains normal, and this is the key to identifying the two.

Examination of elbow dislocation

For this disease, X-ray examination is the basis of diagnosis. The positive lateral slice of the elbow can show the type of dislocation, combined with fracture, and is different from the supracondylar fracture.

Traumatic fracture of the elbow joint, changes in the soft tissue X-ray signs around the dislocation joint, except for the muscle gap showing blur, disappearance, and increased density, the X-ray change of the elbow joint fat space is an important indirect sign of the joint capsule hemorrhage, and the post-traumatic joint capsule When it is torn, the blood flows out of the joint capsule. At this time, the fat gap of the elbow joint is blurred and disappears. When the amount of fluid in the joint capsule is large, the fat pad of the elbow joint is changed by the "eight character", and the joint capsule effusion When the amount is small, only the elevation of the elbow anterior fat space can be found. It is considered that the observation of the changes of the soft tissue X-ray signs around the elbow joint has important clinical significance for avoiding the missed diagnosis of the elbow joint fine fracture, and it is considered that the elbow joint is slightly fractured and the fat space is dislocated. The indirect signs of "eight characters" are not only common in young children, juveniles, but also in adult patients.

Diagnosis and diagnosis of elbow dislocation

diagnosis

1. History of trauma, the most common to fall to the palm of your hand.

2. Clinical manifestations: the affected area is swollen, painful, unable to move. The patient holds the affected side forearm with a healthy hand. The elbow joint is in a semi-extended position. When the passive movement is not straight, the elbow is not straight, and the elbow is empty, and the depression can be touched. The three-point relationship between the elbows is completely destroyed and the normal relationship is lost.

3. Imaging examination, lateral X-ray examination can confirm the diagnosis, and can determine the type of joint dislocation, and whether the fracture and displacement are combined, generally do not need CT and MRI.

Differential diagnosis

1. Identification of total iliac crest separation and elbow dislocation :

Pediatric X-ray film on the humerus small skull center has not appeared, only X-ray film diagnosis, easily misdiagnosed as elbow dislocation, because the strength of the tarsal plate in children is far less than the joint capsule and ligament, the damage to the child's joint parts, the first Consider the possibility of osteophyte injury; secondly, careful and comprehensive clinical examination is also a very important part. According to the swelling, tenderness and blood stasis, there is a preliminary impression on the fracture site, using some special bone markers such as the elbow triangle. To diagnose and identify the separation of the epiphysis of the lower end of the humerus and the dislocation of the elbow. Thirdly, familiar with the anatomical morphology and physiological evolution of the elbow joint in children, in order to improve the diagnostic coincidence rate when reading X-ray films, so as to avoid misdiagnosis and mistreatment, and to give children growth and development. Causes serious consequences.

2. Identification of anterior elbow dislocation and straightening Monteggia fracture with ulnar olecranon fracture :

The main clinical feature of anterior dislocation of the elbow joint with ulnar olecranon fracture is fracture of the proximal ulna. The distal end of the humerus passes through the olecranon, causing anterior dislocation of the elbow joint. Due to multiple high-energy trauma, the proximal ulna is more For complex comminuted fractures, a few can also occur in simple oblique fractures of the olecranon. Most of the ankle joints are accompanied by dislocation, but there is no separation of the upper ulnar joint. The main points of diagnosis are:

(1) Dislocation of the elbow joint.

(2) proximal ulnar fracture.

(3) There is no separation of the upper ulnar joint.

Because this injury is accompanied by ankle dislocation, the clinical is easily confused with the straightening Monteggia fracture, which should be identified at the time of diagnosis.

3, humeral supracondylar fracture and elbow dislocation:

(1) When the supracondylar fracture of the humerus (shoulder type), the elbow joint can be partially moved, the triangle of the elbow does not change, the upper arm is shortened, and the forearm is normal.

(2) When the elbow joint is dislocated, the elbow joint is elastically fixed, the elbow triangle is changed, the upper arm is normal, and the forearm is shortened.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.