Salter III Classification

Fractures of a child's growth plate, or epiphyseal plate, whether in the hand, leg or foot, present medical issues, such as growth interference and diminished function. Salter III classification refers to the Salter-Harris method of classifying growth plate fractures. Named for Drs. Robert Salter and William Harris who first classified these injuries in 1963 and involve the part of the bone that has not hardened. Proper classification of the fracture aids in treatment and recovery.

Physis

• The medical term, physis, defines the growth plate of a young child. It is an area of cartilage that regulates and determines the final shape of the bone and is found near each end of a bone -- since a child's bone grows from the end outward, not from the middle. Once a child finishes growing, the physis hardens. Prior to that time, the physis is subject to fracture due to its condition. The Salter-Harris I classification involves a fracture solely to the physis. These fractures rarely have complications and can be difficult to diagnose unless the physis is displaced.

Metaphysis

• The large part of the bone on the other side of the physis away from the end is called the metaphysis. A Salter-Harris II classification involves a fracture of the physis that extends into the metaphysis. According to the American Academy of Orthopaedic Surgeons, this type of fracture is the most common among children as the fracture breaks through the growth plate and into the bone shaft. Most fractures will heal with the use of a cast, although sometimes surgery is required.

Epiphysis

• The part of the bone between the growth plate and the end of the bone is the epiphysis. Salter-Harris III classification involves a fracture to the physis, or growth plate, that extends into the epiphysis. This fracture can involve breaking off a piece of the end of the bone, or epiphysis. Type III fractures are more likely in older children where the physis has begun to harden. This causes the fracture to continue to the end of the bone rather than remaining in the physis. Surgery is required with the fracture being set in place with screws to ensure proper alignment and formation of the bones.

Types IV and V

• Salter-Harris classify two other types of fractures. Type IV involves a fracture that goes through the metaphysis, physis and epiphysis. Surgery and internal fixation are required with possible growth disturbance. Type V injuries are rare but are considered the worst type. They involve a compression injury that crushes the growth plate, requiring surgery. Disruption of growth usually occurs.

Cause and Effect

• According to the American Academy of Orthopaedic Surgeons, 15 to 30 percent of childhood fractures involve the growth plate. Growth plate fractures primarily occur due to injuries in sports such as basketball or football and in recreational sports like biking, sledding or skiing. The long-term outcome for the fractures are usually good. Type III fractures, due to the surgery, require follow-up medical care to ensure the bones are healing properly and the fractured bone's growth has not been altered.