Pediatric Elbow Injuries
Pediatric elbow injuries account for 8-9 percent of childhood upper extremity fractures. Most elbow injuries in kids involves the distal humerus, especially between the condyles. Many of these fractures occur in boys at around 5-10 years of age.
There are three elbow joints: the radiocapitellar, the ulnohumeral, and the proximal radioulnar joints. There can be disruption of any of these joints. The most common injury is a fall on the outstretched hand. There can also be a direct hit to the elbow, such as in a motor vehicle accident or being struck by a baseball bat.
Patients usually present with deformity, pain in the elbow and refusal to use the arm. The entire arm should be evaluated if there is elbow pain because there can be referred pain to the elbow. Neurovascular compromise is possible. There can be open fractures at any point in the injured area.
X-ray of the front and sides of the elbow should be taken. A fat pad can be seen as the only sign of a nondisplaced fracture. They may not be seen if the joint capsule is disrupted, which can compress the joint fluid.Specific Fractures
Supracondylar humerus fractures. This can involve up to 75 percent of elbow injuries. The peak incidence is 5-8 years of age. Any older than that and dislocations are more prevalent. The non-dominant side is usually affected. There is ligamentous laxity in kids so the elbow can become hyperextended. The main mechanism of injury include the hyperextension of the elbow in a fall on the outstretched hand. There can be injury with a fall to the flexed elbow.
The patient will have a swollen and tender elbow and decreased range of motion. The skin can be dimpled at the site of the fracture or there can be S-shaped angulation of the elbow. A neurovascular examination is necessary. A total of 99 percent of fractures are of the supracondylar type, which involves the humerus. The rest are of the extension type of fracture.
Treatment involves using a long arm splint or cast with the elbow flexed to 90 degrees for 2-3 weeks. Open reduction and internal fixation needs to be done if the fracture is unstable or an open fracture. Pins can be used to make the fracture stable.
Complications include nerve injury, vascular injury, loss of motion, angular deformity, compartment syndrome, and bone formation in the muscle.
Lateral condylar fractures. The peak age of this type of fracture is 6 years. There is a less satisfactory outcome when compared to supracondylar fractures because they are commonly missed if subtle fractures exist. There is also a greater incidence of growth problems.
The main mechanisms of injury are when there is a varus stress on the elbow which results in an avulsion fracture of the distal humerus and if there is a fall on the outstretched hand with the elbow extended. The individual does not have a deformity in most situations but instead has a small amount of swelling. There can be crepitus when pronating or supinating the forearm. The range of motion of the elbow is painful to do. X-rays of the front and side of the elbow often identify the fracture. Varus stress views can show subtle fractures.
There are two types of fracture classification: the Milch system and the Jakob system. The Jakob fractures vary according to the displacement of the fracture.
Treatment includes not using surgery if the fracture is nondisplaced. A posterior splint or long arm cast can be used for 3-6 weeks. Closed reduction can be done in certain fractures with pins placed to hold the reduction in place. If the fracture is unstable, surgery is necessary to stabilize the fracture and reduce it. If 3-6 weeks have gone by, the elbow should not be treated with surgery because there is a high risk of bony cell death and joint stiffness if surgery is attempted.
Complications include lateral condylar overgrowth with bone spur formation, delayed union or non-union, angular deformity, neurological compromise or bony cell death.
Medial condylar physeal fractures. This is a rare type of fracture occurring mostly in 8-14 year old kids. The mechanism of injury is direct trauma to the point of the elbow and an indirect fall on the outstretched arm with a valgus strain on the elbow.
There is usually pain, tenderness and swelling at the medial elbow. Pain is worse when the wrist is flexed. X-rays can show the fracture. In young kids, an arthrogram may be necessary. Stress views can help define the difference between an epicondylar fracture and a condylar fracture. An MRI can help identify the direction of the fracture line.
Treatment involves immobilization in a long arm cast or using a long splint. These can be used for 3-4 weeks before doing range of motion and strengthening exercises. Closed reduction may not be able to be done because of soft tissue swelling so an open reduction is used. If the fracture does not reduce well, open reduction is needed.
Complications include missed diagnosis, non-union, angular deformity, osteonecrosis, and ulnar neuropathy.
Radial head fractures. These represent 5-8.5 percent of elbow fractures, usually seen in 9-10 year olds. It is often associated with fractures of the olecranon, coronoid, and medial epicondyle fractures. The mechanism of injury is a fall on the outstretched hand or direct blow to the head of the radius. Repetitive stress from pitching can cause a fracture of this bone.
Regular AP and lateral views of the elbow should show the fracture. There are some special views that can be done as well. A fat pad sign may be seen as evidence of fracture. An MRI can help identify occult fractures. Comparison with the opposite side of the body can help show a hidden fracture.
Treatment involves immobilization with or without closed reduction, depending on whether or not the fracture is displaced. After reduction the arm should be pronated with a long arm cast at 90 degrees elbow flexion. After 10-14 days, range of motion exercises should be done. Some fractures need surgery to reduce with fixation done using Kirschner wires. This must be done for widely displaced fractures or those that can’t be done by closed means. Up to 23 percent of patients will have a poor prognosis, regardless of how they are treated.
Complications include radial head overgrowth, decreased range of motion, premature physeal closure, bone cell death of the radial head, neurologic damage, and bone formation in the muscle.
Elbow Dislocations. This represents 3-6 percent of elbow injuries. There is a great incidence of fractures associated with this injury. The injury is usually caused by a fall on the outstretched hand or elbow that unlocks the olecranon process from the trochlea to cause a dislocation. There can be anterior or posterior dislocations. The person presents with deformity and inability to move the elbow. Massive swelling is usually present. There is a significant risk of arterial and nerve injury. Compartment syndrome must be looked out for.
Standard x-rays of the elbow should be done to evaluate the elbow. Fractures must be looked for as well as the dislocation.
The dislocation can be done with sedation and pain relief. Young children can be placed prone with the arm dangling down and traction applied. Older children may be placed supine with the forearm supinated and the elbow flexed. Traction is applied and the elbow is relocated. If closed reduction is not possible, open reduction should be undertaken.
Complications include loss of full extension of the elbow, neurological deficits (10 percent), vascular injury, compartment syndrome, instability of the elbow, bone formation in the muscle, osteochondral fractures, and radioulnar synostosis.