A Salter-Harris fracture is an injury to the growth plate area of a child’s bone.
The growth plate is a soft area of cartilage at the ends of long bones. These are bones that are longer than they are wide. Salter-Harris fractures can occur in any long bone, from fingers and toes, to arm and leg bones.
A child’s bone growth occurs mainly in the growth plates. When children are fully grown, these areas harden into solid bone.
The growth plates are relatively weak and can be injured by a fall, a collision, or excessive pressure. Salter-Harris fractures make up 15 to 30 percent of bone injuries in children. Most commonly these fractures occur in children and teenagers during sports activity. Boys are twice as likely as girls to have a Salter-Harris fracture.
It’s important to diagnose and treat a Salter-Harris fracture as soon as possible to ensure normal bone growth.
What are the symptoms?
Salter-Harris fractures most often occur with a fall or injury that causes pain. Other symptoms include:
- tenderness near the area
- limited range of motion in the area, especially with upper body injuries
- inability to bear weight on the affected lower limb
- swelling and warmth around the joint
- possible bone displacement or deformity
Types of Salter-Harris fractures
Salter-Harris fractures were first categorized in 1963 by Canadian doctors Robert Salter and W. Robert Harris.
There are five main types, distinguished by the way the injury impacts the growth plate and surrounding bone. The higher numbers have a higher risk of possible growth problems.
The growth plate is known as the physis, from the Greek word “to grow.” The growth plate is located between the rounded top of the bone and the bone shaft. The rounded bone edge is called the epiphysis. The narrower part of the bone is called the metaphysis.
This fracture occurs when a force hits the growth plate separating the rounded edge of the bone from the bone shaft.
This fracture occurs when the growth plate is hit and splits away from the joint along with a small piece of the bone shaft.
This fracture occurs when a force hits the growth plate and the rounded part of the bone, but doesn’t involve the bone shaft. The fracture may involve cartilage and enter into the joint.
This type usually happens after age 10. About 10 percent of Salter-Harris fractures are type 3.
This fracture occurs when a force hits the growth plate, the rounded part of the bone, and the bone shaft.
About 10 percent of Salter-Harris fractures are type 4. This can happen at any age, and it may affect bone growth.
This uncommon fracture occurs when the growth plate is crushed or compressed. The knee and ankle are most often involved.
Another four fracture types are extremely rare. They include:
- Type 6 which affects connective tissue.
- Type 7 which affects the bone end.
- Type 8 which affects the bone shaft.
- Type 9 which affects the fibrous membrane of the bone.
How is this diagnosed?
If you suspect a fracture, take your child to a doctor or the emergency room. Prompt treatment for growth plate fractures is important.
The doctor will want to know how the injury occurred, whether the child has had previous fractures, and whether there was any pain in the area before the injury.
They’ll likely order an X-ray of the area, and possibly of the area above and below the injury site. The doctor may also want an X-ray of the unaffected side to compare them. If a fracture is suspected but doesn’t show up in the image, the doctor may use a cast or splint to protect the area. A repeat X-ray in three or four weeks can confirm the fracture diagnosis by imaging new growth along the break area.
Other imaging tests may be needed if the fracture is complex, or if the doctor needs a more detailed view of soft tissue:
- A CT scan and possibly an MRI may be useful for evaluating the fracture.
- CT scans are also used as a guide in surgery.
- An ultrasound may be useful for imaging in an infant.
Type 5 fractures are difficult to diagnose. A widening of the growth plate may provide a clue to this type of injury.
Treatment will depend on the type of Salter-Harris fracture, the bone involved, and whether the child has any additional injuries.
Usually, types 1 and 2 are simpler and don’t require surgery.
The doctor will put the affected bone in a cast, splint, or sling to keep it in the right place and protect it while it heals.
Sometimes these fractures may require nonsurgical realignment of the bone, a process called closed reduction. Your child may need medication for pain and a local or possibly general anesthetic for the reduction procedure.
Type 5 fractures are more difficult to diagnose and are likely to affect proper bone growth. The doctor may suggest keeping weight off the affected bone, to make sure that the growth plate isn't damaged further. Sometimes the doctor will wait to see how bone growth develops before treatment.
Types 3 and 4 usually need a surgical realignment of the bone, called open reduction.
The surgeon will put the bone fragments into alignment and may use implanted screws, wires, or metal plates to hold them in place. Some Type 5 fractures are treated with surgery.
In surgery cases, a cast is used to protect and immobilize the injured area while it heals. Follow-up X-rays are needed to check on bone growth at the injury site.
Recovery times vary, depending on the location and severity of the injury. Usually, these fractures heal in four to six weeks.
The length of time the injury remains immobilized in a cast or sling depends on the particular injury. Your child may need crutches to get around, if the injured limb shouldn’t be weight-bearing while it’s healing.
After the initial period of immobilization, the doctor may prescribe physical therapy. This will help your child regain flexibility, strength, and range of motion for the injured area.
During the recovery period, the doctor may order follow-up X-rays to check on healing, bone alignment, and new bone growth. For more serious fractures, they may want regular follow-up visits for a year or until the child’s bone is fully grown.
It may take time before your child can move the injured area normally or resume sports. It’s recommended that children with fractures involving a joint wait four to six months before participating in contact sports again.
What’s the outlook?
With proper treatment, most Salter-Harris fractures heal without problems. More severe fractures can have complications, especially when the leg bone near the ankle or thigh bone near the knee are involved.
Sometimes bone growth at the injury site may create a bony ridge that needs surgical removal. Or, lack of growth can stunt the injured bone. In this case, the injured limb may be deformed or have a different length from its opposite. Lasting problems are most common with injuries to the knee.
Research is ongoing into cellular and molecular therapies that may help regenerate growth plate tissue.
Most Salter-Harris fractures occur because of a fall while playing: falling off a bicycle or skateboard, falling off playground equipment, or falling while running. Even with safety precautions, childhood accidents happen.
But there are specific measures you can take to prevent sports-related fractures. About a third of Salter-Harris fractures occur during competitive sports, and 21.7 percent occur during recreational activities.
The American Medical Society for Sports Medicine suggests:
- limiting weekly and yearly participation in sports that involve repetitive movements, such as pitching
- monitoring sports training and practice to avoid overuse during periods of rapid growth, when teens may be more prone to growth plate fractures
- holding pre-season conditioning and training, which can reduce injury rates
- emphasizing skill development, rather than “competition”