Children present with different injuries than are commonly seen in adults. Because ligamentous attachments are stronger than bony attachments in children, fractures are more prevalent than sprains, dislocations, and strains. This chapter discusses musculoskeletal injuries that are unique to the pediatric population.
The following terms are typically used in pediatric orthopedics:
- Physis: The cartilaginous growth plate that appears lucent on radiographs.
- Epiphysis: A secondary ossification center at the ends of long bones that is separated by the physis from the remainder of the bone.
- Apophysis: A secondary ossification center at the insertion of tendons onto bones.
- Diaphysis: The shaft of a long cortical bone.
- Metaphysis: The widened portion at the ends of a bone adjacent to the physis.
It is important to carefully palpate the uninjured extremity first in order to obtain the child's confidence. It is also important to determine whether the history that is given by the parents or guardians is consistent with the observed injuries or whether there is a suggestion of child abuse.
A fracture may be difficult to find in an injured extremity in a child who is crying. On physical examination, palpation of areas that are not fractured will generally hurt less than areas that are injured. Palpation should be gentle, but with enough pressure so as to make a comparison between the normal and abnormal region in a child who is upset.
Neurologic evaluation of the extremity is often difficult. A generalized withdrawal response can be evaluated by using pinprick. Wrinkling of skin suggests that the nerve is intact. In assessing the vascular status of the extremity, palpation of pulses may be difficult because of the subcutaneous fat and therefore it is important to assess and document capillary refill time.
When performing plain radiographs of children, at least two views that are perpendicular to one another must be obtained. In addition, views of the entire extremity including both joints at the end of the long bones are integral to the patient's evaluation. Comparison views are invaluable, particularly when looking for a subtle fracture. The growth plates in comparison views taken in exactly the same position should be closely evaluated. Anterior and posterior fat pad signs will help identify subtle fractures (Fig. 6–1). The epiphyseal centers can often be a challenge when reading plain films and therefore it is imperative that the practitioner knows when these centers begin to appear (Fig. 6–2).
A subtle Salter III fracture of the elbow is shown on the lateral view. Notice the anterior fat pad and posterior fat pad.
The epiphyseal regions at the major joints in the body. The age at which the centers of ossification appear on roentgenograms is shown in months or years. The age at which union occurs is shown in parentheses. AB, at birth.
The Salter–Harris classification refers to physeal fractures (Figs. 6–3 and 6–4).1–3 This classification is a radiologic classification and is not anatomical, nor related to the mechanism or severity of injury.
The Salter–Harris classification system used in epiphyseal injuries.
A. Salter II fracture of the distal radius. B. Salter III medial femoral condyle fracture. C. Salter IV distal radius fracture.
A Salter I fracture is a fracture through the physis and accounts for 6% of all physeal fractures. These fractures may be displaced or nondisplaced; however, there is no extension proximally or distally. A nondisplaced Salter I fracture may not be obvious on x-ray acutely; therefore, clinical suspicion is the key to making the diagnosis. Patients will typically present with circumferential tenderness along the physeal area. These fractures commonly occur in the distal tibia and fibula, and may present with the same mechanism as a sprained ankle without any ligamentous tenderness. In addition, these fractures occur in the hands and fingers of children.
A Salter II fracture is a fracture through the physis, which continues on into the metaphysis. These fractures account for 75% of all physeal fractures. Undisplaced fractures generally do not cause growth disturbances.
In a Salter III fracture, the fracture extends through the physis and continues into the epiphysis. These fractures account for approximately 8% of all fractures and usually occur in children who are older with a partially closed physis. These fractures should be referred early in order to have careful and accurate reduction.
Salter IV fractures go through the physis and into both the epiphysis and the metaphysis. These fractures account for 10% of physeal fractures. Salter IV fractures need accurate reduction to prevent bone bridging between the epiphysis and the metaphysis because these fractures involve fracture through the physis and extend both proximally and distally. This fracture and the subsequent bridging can lead to partial or a complete growth arrest.
Salter V fractures are crush injuries of the physis and are the most serious type of fracture. Fortunately, Salter V fractures only account for 1% of physeal fractures. Salter V fractures may not be clearly visible at the time of injury and are often diagnosed in retrospect when growth arrest is noted. Comparison views of the contralateral limb may be helpful in making ...