The Salter-Harris category classifies growth plate injuries in the order of increasing severity (see Figure 1).
SCAN IN FIGURE 1 HERE
Involvement of the Growth PlateSalter-Harris Classification
I fracture through growth plate
II fracture through growth plate and metaphysis
III fracture through growth plate and epiphysis
IV fracture through growth plate, metaphysis, and epiphysis
V compression fracture through growth plate
Salter-Harris Classification: Type I through V
Type I: The Type I fracture completely separates the epiphysis from the metaphysis; the germinal cells remain with the epiphysis. Type I injuries are usually the result of shearing, torsion, or avulsion force. The radiographs, however, can also demonstrate some widening of the growth plate region or some displacement of the epiphysis. Healing occurs in 3-4 weeks and problems are rare; the most serious sequela is avascular necrosis of the femoral head. It may be difficult to distinguish a Type I lesion from a Type V lesion; the mechanism of injury is the best guide and Type V injuries are produced by axial compression.
Type II: In the
Type II fracture, the plane of cleavage passes through most of the epiphyseal plate before exiting through the metaphysis. A lateral displacement force tears the periosteum on one side and leaves it intact on the side of the metaphyseal fragment. Over-reduction is prevented by the intact periosteum on one side and chronic disability is unusual.
Type III: The Type III is a result of an axial compression injury. This fracture passes from the articular surface through the epiphysis, and then courses through the growth plate for a variable distance before exiting. This fracture does not involve the metaphysis. Since the fracture is intra-articular it requires accurate reduction to prevent joint incongruity. The most common site of injury is the distal tibial epiphysis toward the end of the growth period when the medial half of the growth plate is closed.
Type IV: The Type IV injury most commonly involves the lateral condyle of the humerus. The fracture passes from the joint surface, across the epiphyseal growth plate and into the metaphysis. This fracture usually requires open reduction and internal fixation to secure a smooth joint surface. There are several varieties of this injury as demonstrated in the diagram (see Figure 2). The risk of bony callous bridge crossing the growth plate is greatest when the ossified portion of the epiphysis has been fractured.
There are several varieties of the Type IV injury as demonstrated.
ARNETTA: SCAN IN FIGURE 2 HERE
The risk of a bony callous bridge crossing the growth plate is greatest when the ossified portion of the epiphysis has been fractured.
Type V: The Type V injury is rare. The growth plate is crushed by an axial compression injury and no further growth will occur. Luckily these are rare since they require very aggressive orthopedic management.
I cannot avoid discussing Battered Child Syndrome when reviewing injuries to the growth plate. The hallmark radiographic sign of Battered Child Syndrome is multiple fractures that are of different stages of healing. Rib fractures and Salter Type I fractures are frequently found. A corner metaphyseal fracture in a long bone, elbows and knee is due to excessive shaking of the child causing a periosteal avulsion. Similar changes are seen in a Salter Type I fracture which is constantly being disrupted.
Children infrequently harm themselves when they fall. It has been reported that 10 percent of all injuries in the child under two years of a age are due to accidental injury. Twenty-five percent of all fractures in children under three years of age are due to battery. Some fractures of battered children are indistinguishable from those produced by a motor vehicle accident.
Rather than obtain multiple films in the evaluation of these children, many institutions have decided to utilized bone scanning as the initial survey tool to determine locations of the injuries.
Battered Child Syndrome is a very serious diagnosis and carries many medical and legal consequences. If a practitioner is suspicious that this may be the case, a second opinion is a strongly recommended as it is required that these cases be reported.
Deborah Pate, DC, DACBR
San Diego, California
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