Bone fractures involving the growth plate in children are common, and can result in bone growth delay or arrest. The Salter-Harris radiologic classification system was developed in the 1960s to describe these types of fractures, based on the extent of damage to the growth plate. Because pediatric patients often are examined in the ED for orthopedic problems, understanding the Salter-Harris classifications can help when you assess children with traumatic bony injuries. Let's take a closer look.

Five types of fractures

The SALTR mnemonic is an easy way to remember the five types of growth plate fractures that can place a pediatric patient at risk for bone growth disturbance:

* S-fracture involves a Slip or Separation of the growth plate (Type I)

* A-fracture is Above the growth plate (Type II)

* L-fracture is Lower than the growth plate (Type III)

* T-fracture is Through the growth plate (Type IV)

* R-fracture involves a cRush of the growth plate (Type V).

Type I

In a type I fracture, the epiphysis is slipped or separated from the metaphysis. The X-ray will show soft-tissue swelling near the epiphyseal line, and displacement of the epiphysis from the metaphysis. You also may see bony avulsion at the periosteal attachment. These fractures occur most commonly in the distal tibia or fibula.

Because X-ray findings can be very subtle, patient exam is the most important component of assessment in these fractures. The patient will be point tender over the growth plate, so he should be reevaluated by an orthopedic surgeon. Fortunately, type I fractures rarely cause growth disturbances.

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Type II

In this type of fracture, the epiphyseal plate is slipped with a metaphyseal fracture, producing a triangular fragment of the metaphysis. This is the most common type of growth plate fracture.

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Type III

The epiphyseal plate is slipped with an intra-articular fragment of the epiphysis in this fracture. Type III fractures typically occur at the distal tibial epiphysis, usually in an older child with a partially closed physis. The patient will have point tenderness over the growth plate. Open reduction usually is needed for this type of fracture, to prevent growth disturbance. The blood supply that enters from the epiphyseal surface must be adequate for the bone to heal properly; without a good blood supply, avascular necrosis may occur.

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Patients with type III fractures will need immobilization for 4 to 6 weeks with close observation by an orthopedic surgeon.

Type IV

This fracture involves the epiphysis, physis, and metaphysis and commonly occurs at the lateral condyle of the humerus. The patient often will have point tenderness and swelling at the growth plate, and will need open reduction and internal fixation. Postoperatively, he'll need 4 to 6 weeks of immobilization and close observation by an orthopedic surgeon. Growth disturbance and joint deformity can occur with this type of fracture, and because this is an intra-articular fracture, the prognosis may be poor if precise reduction isn't achieved.

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Type V

This injury is a crush injury to the growth plate with no epiphyseal or metaphyseal fracture. Type V fractures usually involve an axial load mechanism of injury, such as a fall from a height. The knee and distal tibial physis are common sites of injury, and these fractures are difficult to detect because the epiphysis doesn't appear to be displaced. The initial X-ray may appear normal, so comparison films may be helpful.

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Treatment is to avoid weight bearing and close observation by an orthopedic surgeon. Unfortunately, type V fractures often are diagnosed in retrospect when growth arrest is discovered.

Real-world situations

Now let's look at some cases of pediatric fractures and how to handle them. Suppose you're caring for Pete Lucca, 15, who sustained an injury to his right thumb while catching a football. From his description, you know it's a hyperex-tension injury. He has tenderness and swelling on the ulnar aspect of the first metacarpal joint on his right thumb, ecchymosis of the volar aspect of the thumb and thenar area.

An X-ray reveals a type II fracture of the metacarpal joint of Pete's right thumb, with slippage of the proximal phalanx and a fracture through the metaphysis. Pete is placed in a thumb spica splint and referred to an orthopedic surgeon, who placed him in a thumb cast for 4 weeks. He was later able to resume normal activities without restriction.

Now let's consider Tyler Newton, 13, who comes to the ED with his father after being injured in a basketball game. Tyler has right knee pain and swelling; his father says he collided with another player during the game. Tyler's right foot was planted as he tried to catch the ball, and the other player struck him in the medial aspect of the knee, knocking him to the floor. Tyler wasn't able to bear weight immediately after the accident, and says his knee is very painful.

An X-ray reveals a fracture through the epiphysis with separation of the physis of the distal femur, or a type III fracture. Tyler is placed in a knee immobilizer, admitted to the hospital, and referred to an orthopedic surgeon for operative intervention. He's more comfortable now that he's been placed in the knee immobilizer.

By understanding common pediatric fractures and their classifications, you can help patients get appropriate treatment and reduce permanent disabilities in patients with these types of injuries.

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