Physeal fractures are described using Salter-Harris classification, which allows for prognostic information regarding premature closure of the growth plate and poor functional outcomes. The higher the type number, the more likely the patient will have complications. There are five main groups (Fig. 198-2):Type I: transverse fracture through the physis; growth disturbance is unusual
Type II: fracture through a portion of the physis and metaphysis; most common type of Salter-Harris fracture (75%)
Type III: fracture through a portion of the physis and epiphysis into the joint that may result in complication because of intra-articular component and because of disruption of the growing or hypertrophic zone of the physis
Figure 198-1 The greenstick fracture is an incomplete fracture.
(Modified from White N, Sty R: Radiological evaluation and classification of pediatric fractures, Clin Pediatr Emerg Med 3:94–105, 2002.)
Type IV: fracture through the metaphysis, physis, and epiphysis with a high risk of complicationType V: a crush injury to the physis with a poor functional
Types I and II fractures can often be managed by closed reduction and do not require perfect alignment. A major exception is the type II fracture of the distal femur, which is associated with a poor outcome unless proper anatomic alignment is obtained. Types III and IV fractures require anatomic alignment for successful treatment. Type V fractures are rare and often result in premature closure of the physis.
The majority of pediatric fractures can be managed with closed methods. Some fractures need closed reduction to improve alignment. Approximately 4% of pediatric fractures require internal fixation. Patients with open physes are more likely to require internal fixation if they have one of the following fractures:Displaced epiphyseal fracturesDisplaced intra-articular fracturesFractures in a child with multiple injuriesOpen fracturesUnstable fractures
The goal of internal fixation is to improve and maintain anatomic alignment. This is usually done with Kirschner wires, Steinmann pins, and cortical screws with subsequent external immobilization in a cast until healing is satisfactory. After healing, the hardware is frequently removed to prevent incorporation into the callus and prevent physeal damage.
External fixation without casting may be necessary for pelvic fractures causing hemodynamic instability. Fractures associated with soft tissue loss, burns, and neurovascular damage may benefit from external fixation.
Fracture remodeling occurs because of a combination ofperiosteal resorption and new bone formation. Many pediatric fractures do not need perfect anatomic alignment for proper healing. Younger patients have greater potential for fracture remodeling. Fractures that occur in the meta-physis,near the growth plate, may undergo more remodeling. Fractures angulated in the plane of motion also remodel very well.Intra-articular fractures, angulated or displaced diaphysealfractures, rotated fractures, and fracture deformity not in theplane of motion tend not to remodel as well.
Overgrowth occurs in long bones as the result of increased blood flow associated with fracture healing. Femoral fractures in children younger than 10 years of age will frequently overgrow 1 to 3 cm. This is the reason end-to-end alignment for femur and long-bone fractures may not be indicated. After 10 years of age, overgrowth is less of a problem, so end-to-end alignment is recommended.
Fractures and injuries to the physis can result in premature closure. If it is a partial closure, the consequence may be an angular deformity. If it is a complete closure, limb shortening may occur. The most commonly affected locations are the distal femur and the distal and proximal tibia.