Pediatric Shoulder Injuries
Proximal humeral fractures are uncommon, accounting for less than five percent of children’s fractures. They are more common in adolescents who participate in sports activities. Newborns can sustain a proximal humerus fracture as a part of birth trauma. Eighty percent of the growth of the humerus occurs at the proximal end so there is a great deal of potential for modeling.
The head of the humerus turns to bone at six months of age. The greater tuberosity turns to bone at 1-3 years of age and the lesser tuberosity turns to bone at 4-5 years of age. Because the joint capsule extends down to the metaphysis, some fractures of the proximal humerus will involve the joint.
The mechanisms of injury can be direct or indirect. In an indirect injury, there is a fall backward onto the outstretched hand with full extension of the elbow and backward flexion of the wrist. If the injury happens at birth, the arm is usually hyperextended or rotated at the time of birth. An injury to the humerus can occur if there is shoulder dystocia. If the injury is direct, it is caused by a blow to the posterolateral aspect of the shoulder.
Evaluation of Pediatric Shoulder Injuries
Neonates will have pseudoparalysis with the arm extended. The baby will have a fever and there can be shoulder dislocation, infection, brachial plexus injury and clavicle fracture as part of the injury. In older kids, there is pain, lack of mobility, bruising and tenderness/crepitus to palpation. The arm will be internally rotated; many nerves can be injured so a neurovascular evaluation must be done.
X-ray of the front, side and axillary views will show the fracture. Ultrasound might need to be done in newborns because there is little ossification. CT scanning might need to be done or MRI scanning to detect occult fractures or dislocation.
Classification of Proximal Humerus Fractures
There are two major classification systems, including the Salter-Harris classification, which involves growth plate injuries and the Neer-Horowitz classification system, which involves displacement of the growth plate fractures.
Treatment of Proximal Humerus Fractures
The treatment of these fractures depends on the child’s age and the pattern of fracture. Neonates tend to heal very well with ultrasound used to reduce the fracture if necessary. If the fracture is stable, the humerus is held against the body for 5-10 days. If the fracture is unstable, the arm is abducted and externally rotated for 3-4 days so that callus formation can occur.
If the child is 1-4 years old, the arm is reduced and held in a sling for about ten days. Remodeling can be extensive so these tend to heal well. For 5-12 year old children, a sling and a swathe is used in stable fractures. In unstable fractures, a shoulder spica cast is placed with the arm in a position of saluting for 2-3 weeks after which a sling is used with increased motion as tolerated. If the child is 12 years or older, a sling and a swathe are used for 2-3 weeks after which there is an increase in range of motion of the arm. Unstable fractures need a shoulder spica cast with the arm in the saluting position for 2-3 weeks with increased range of motion after that.
Surgery is used in open fractures or in fractures with nerve and blood vessel damage. Displaced fractures may need surgery; pins or wires are used to hold the fracture segments together. The younger the patient, the better is the remodeling of bone.
Complications of Proximal Humerus Fractures
The main complications include a varus deformity of the fracture and inequality of the limb length, especially in those fractures treated with surgery. Loss of motion is possible along with osteonecrosis, nerve injury and arrest of growth at the level of the growth plate.
These are common fractures in kids and can happen at the time of a difficult birth, particularly in large babies. Most of these fractures are midshaft fractures at 80 percent of fractures. The rest are medial or lateral. Clavicle fractures ossify early but is the last bone to fuse at 22-25 years of age. Remodeling happens fairly easily.
The mechanism of injury is a fall to the outstretched hand or to direct trauma on the clavicle. Birth injury can cause a fracture of this bone. True dislocations are extremely rare. Direct trauma to the acromion account for lateral clavicle fractures.
Birth fractures are obvious injuries with a mass seen over the fracture area. Older kids will have a mass that is painful over the clavicle with bruising and crepitus. The neurovascular status of the arm must be evaluated because brachial plexus injuries and blood vessel injury can occur.
X-ray can be used in older kids but newborns may need ultrasound to evaluate the bone. If there is shortness of breath, a chest x-ray should be done to make sure there is no pneumothorax. CT scan might be necessary in medial fractures and in growth plate injuries.
Classification can involve the location, displacement and angulation of the clavicle. The fracture can be open or closed. There can be different fracture types, including comminuted, greenstick or segmental fractures. Altman fractures involve three different locations of the fracture.
Treatment includes slings or figure of eight bandaging for 2-3 weeks in newborns. For older kids, a sling or figure of eight bandage can be used for 2-4 weeks or until the fracture heals. In older kids with widely displaced fractures, open reduction and internal fixation may have to be done. Any bony prominences will likely remodel themselves over time.
The main complications include neurovascular compromise, malunion or non-union of the fracture. These are rare. Injury to the lung is possible but is also rare.
AC Joint Injuries
Injuries to the AC joint are rare in kids under sixteen years of age. The periosteal sleeve of the clavicle goes into the joint itself, somewhat protecting it. The major mechanism of injury is athletic injuries in which there is direct trauma to the acromion. Dislocation of the AC joint is only rarely possible in kids.
The person should be evaluated sitting or standing so as to stress the joint when evaluating the injury. X-rays of the shoulder with or without weights to assess the AC joint ligaments. The joint injury is classified according to the presence or absence of strain as well as dislocation degree of the joint. In most cases, surgery is not indicated unless there is severe displacement of the distal clavicle. A sling can be used until the joint heals. Early range of motion should be undertaken with full healing in 4-6 weeks. If there is displacement, surgical intervention should be undertaken.
Complications include the possibility of neurovascular injury, especially with posterior and inferior displacement. An open fracture can occur with severe dislocation of the AC joint.
These are relatively rare because the scapula is relatively protected. When the scapula is fractured, it is often associated with other, more severe injuries in a multiple trauma situation. The mechanism of injury is often because of high energy trauma such as a motor vehicle accident. Avulsion fractures are more common that fractures of the body of the scapula. Many of these fractures are associated with upper torso injuries, pneumothorax, bruising of the lungs, neurovascular injury, spinal fractures, skull fractures and intra-abdominal injuries. The rate of death in scapula fractures is 14 percent because of the other injuries found in these types of fractures.
A full trauma evaluation is necessary in scapula fractures. The person usually presents with the arm held by the opposite hand. Neurovascular status should be evaluated. X-rays should be done to view the scapula. An x-ray that is at a 45 degree angle to the scapula should be done to see the coracoid fracture. CT scan can help view certain kinds of scapula fractures. A chest x-ray should be done because of the incidence of other chest-related injuries along with the scapular fracture.
Scapula fractures can be treated without surgery in kids because the surrounding muscle can hold the fracture in place. If the fracture does not unite, surgery may be indicated. A sling may be indicated in most scapula fractures, especially if not displaced.
Complications include post traumatic osteoarthritis, coexisting injuries, decreased range of motion of the shoulder, malunion, non-union, and injury to the suprascapular nerve.
Dislocation of the Glenohumeral Joint
These rarely occur in kids. Ninety percent include anterior dislocations. The shoulder joint is particularly protected from dislocation. The main mechanisms of injury include birth trauma, direct impact on the shoulder joint or upper extremity trauma. Electric shock or seizure can cause a posterior dislocation. There can be dislocations without trauma because of congenital laxity of the joint.
X-ray can show evidence of the dislocation. There are multiple types of x-ray views that can show the dislocation better. CT scanning can better identify the location of the dislocation. MRI examination can show injuries to the rotator cuff.
Treatment includes closed reduction using traction and counter-traction. The patient can be placed prone onto the gurney with traction and rotation allowed to put the fracture back into position. After reducing the shoulder, it should be immobilized in a sling for up to 4 weeks with gradually increasing range of motion after that. If the dislocation happens without trauma, reduction is all that is necessary.
Complications include recurrent dislocation, shoulder stiffness, and neurovascular injury.