Growth Plate Injuries
What Are Growth Plates?
Growth plates are located on the long bones of children and young people. These plates are areas of growing tissue near the end of the bones. Each long bone has at least two growth plates-one at each end. This is where the long bones grow. When young people finish growing, the growth plates close and are replaced by solid bone. Growth plate injuries occur mainly at the wrist, bones of the legs, or in the ankle, foot, or hip bones.
Who Gets Growth Plate Injuries?
Growth plate injuries happen to children and young people. The growth plate is the weakest part of the growing skeleton. Injuries to the plates are called fractures. Growth plate fractures happen twice as often in boys as in girls. And, fractures are most likely in 14- to 16-year-old boys and 11- to 13-year-old girls.
What Causes Growth Plate Injuries?
Growth plate injuries happen for many reasons. Most occur after a sudden accident, such as falling or being hit hard on the leg. People who sometimes get injuries from overuse include:
- Gymnasts who practice for hours on the uneven bars
- Long-distance runners
- Baseball pitchers perfecting their curve balls.
The top reasons for growth plate injuries are:
- Falling down
- Competitive sports (like football)
- Recreational activities
- Car, motorcycle, and all-terrain-vehicle accidents (only in a small number of cases).
Other reasons for growth plate injuries are:
- Child abuse
- Injury from extreme cold (for example, frostbite)
- Radiation (used to treat certain cancers)
- Neurological disorders that cause people to lose their balance and fall
- Some inherited disorders
- Bone infections.
When to See a Doctor
A child should never have to "work through the pain." Parents should take their child to see a doctor when:
- The child has to stop playing because of pain after a sudden injury.
- The child is less able to play because of an old injury.
- The child's arm or leg bends the wrong way.
- The child cannot move an arm or leg because of pain.
- The pain continues after overuse or injury.1
How Are Growth Plate Fractures Diagnosed?
First, the doctor will find out how the injury happened. Second, he or she will examine the child and use x-rays to find out what kind of fracture it is. Because growth plates have not yet hardened into solid bone, they don’t show on x-rays. Instead, they appear as gaps between the shaft of a long bone, called the metaphysis, and the end of the bone, called the epiphysis. Because injuries to the growth plate may be hard to see on x-ray, an x- ray of the non-injured side of the body may be taken so the two sides can be compared. Magnetic resonance imaging (MRI), which is another way of looking at bone, provides useful information on the appearance of the growth plate. In some cases, other diagnostic tests, such as computed tomography (CT) or ultrasound, will be used.
How Are Growth Plate Injuries Treated?
The treatment depends on the type of fracture. However, with all fractures, treatment should start as soon as possible. Treatment usually involves a mix of the following:
The affected limb is often put in a cast or splint, and the child is told to limit any activity that puts pressure on the injured area.
Manipulation or Surgery
If the fracture is displaced, the doctor will have to put the bones or joints back in their correct positions, either by using his or her hands (called manipulation) or by performing surgery (open reduction and internal fixation). After the procedure, the bone will be set in place so it can heal without moving. This is usually done with a cast that encloses the injured growth plate and the joints on both sides of it. The cast is left in place until the injury heals, which can take anywhere from a few weeks to two or more months for serious injuries. The need for manipulation or surgery depends on the location and extent of the injury, its effect on nearby nerves and blood vessels, and the child’s age.
Strengthening and Range-of-Motion Exercises
These treatments may also be recommended after the fracture is healed.
Long-term follow-up is usually necessary to monitor the child’s recuperation and growth. Evaluation includes x-rays of matching limbs at 3- to 6-month intervals for at least 2 years. Some fractures require periodic evaluations until the child’s bones have finished growing. Sometimes a growth arrest line may appear as a marker of the injury. Continued bone growth away from that line may mean that there will not be a long-term problem, and the doctor may decide to stop following the patient.
How Well Do Children Grow After a Growth Plate Injury?
Most growth plate fractures get better and do not cause any lasting problems. Occasionally, the bone stops growing and ends up shorter than the other limb. For example, a fractured leg might end up shorter than the other leg. Or, if only part of the growth plate is injured, the limb can become crooked when only part of the bone keeps growing. Whether an arrest of growth occurs depends on the following factors, in descending order of importance:
- Severity of the injury – If the injury causes the blood supply to the epiphysis to be cut off, growth can be stunted. If the growth plate is shifted, shattered, or crushed, a bony bridge is more likely to form and the risk of growth retardation is higher. An open injury in which the skin is broken carries the risk of infection, which could destroy the growth plate.
- Age of the child – In a younger child, the bones have a great deal of growing to do; therefore, growth arrest can be more serious, and closer surveillance is needed. It is also true, however, that younger bones have a greater ability to remodel.
- Which growth plate is injured – Some growth plates, such as those in the region of the knee, are more responsible for extensive bone growth than others.
- Type of growth plate fracture—There are five fracture types based on the extent of damage done to the growth plate.
What Are Researchers Trying to Learn About Growth Plate Injuries?
Researchers are searching for better ways to diagnose and treat growth plate injuries. For example, they are:
- Finding ways to help bones continue to grow after fractures
- Researching drugs that protect the growth plate during radiation treatment
- Finding ways to help damaged muscles, bones, joints, tendons, and ligaments grow back.
1 Adapted from Play It Safe, a Guide to Safety for Young Athletes, from the American Academy of Orthopaedic Surgeons.