Overview of Growth Plate Injuries
The growth plate is the area of tissue near the ends of long bones in children and teens that determines the future length and shape of the mature bone. Each long bone has at least two growth plates, one at each end, and they are longer than they are wide. For example, the femur (thigh bone), radius and ulna (forearm), and the metacarpal bones (hands and fingers) are long bones. Once your child’s growth is complete – sometime during adolescence – the growth plates close and are replaced by solid bone.
The growth plates are weak areas of your child’s growing skeleton. Because they are even weaker than the nearby ligaments and tendons that connect bones to other bones and muscles, growth plates are vulnerable to injury. Injuries to the growth plate (fractures) can result from a single traumatic event, such as a fall or automobile accident, or from chronic stress and overuse.
Children and teens with growth plate injuries often need immediate treatment to prevent problems with bone growth. However, with proper treatment, most growth plate fractures heal without any lasting effect.
Who Gets Growth Plate Injuries?
Because the growth plate is the last area of bone to harden during growth, children and teens are vulnerable to growth plate fractures or injuries. A similar injury in an adult can cause a sprain.
The following factors may increase the chance that your child or teen may injure or fracture their growth plate:
- Sex. Growth plate fractures occur more often in boys than in girls. A girl’s body matures at an earlier age than boys. As a result, girls’ bones finish growing sooner, and the growth plate is replaced with stronger, solid bone at an earlier age.
- Competitive sports. Growth plate injuries often occur in children and teens who participate in competitive sports or activities that increase the risk to fall or be hit, such as:
- Repetitive use. Specializing in one sport and overusing certain limbs or areas of the body before puberty finishes can lead to growth plate injuries.
Types of Growth Plate Injuries
Doctors use a classification system called the Salter-Harris to divide most growth plate injuries and fractures into five types. Understanding the anatomy of long bones can help you understand the types of growth plate injuries. Long bones have four major areas:
- Epiphysis: the end of the bone near the joint.
- Physis: the growth plate.
- Metaphysis: the area between the growth plate and the shaft.
- Diaphysis: the shaft of the long bone.
The Salter-Harris types are:
- Type I happens when the fracture passes through the physis but does not involve the area of bone around the growth plate.
- Type II happens when the fracture runs through the physis and the metaphysis. This is the most common type of growth plate fracture.
- Type III happens when fractures run through the epiphysis. This leads to a separation of epiphysis and physis from the metaphysis.
- Type IV happens when fractures run through the physis, metaphysis, and epiphysis.
- Type V is a compression fracture through the physis that happens when the end of the bone is crushed, and the physis is compressed. This type of fracture is rare.
Sometimes, doctors include the Peterson classification when describing growth plate injuries. This system includes a type VI, which happens when a portion of the epiphysis, physis, and metaphysis are missing. This usually happens from a severe traumatic injury that includes open wounds or compound fractures.
Symptoms of Growth Plate Injuries
Symptoms of a growth plate injury include:
- Persistent pain and tenderness after a sudden or overuse injury.
- Deformity, warmth, or swelling at the end of a bone.
- Changes in how your child bends their limb.
- Inability to move, put pressure on, or bear weight on a limb because of pain.
You may notice that your child self-limits the amount of time playing after a prior injury.
Causes of Growth Plate Injuries
Growth plate injuries can happen for many reasons. A sudden accident can cause growth plate injuries. For example, your child may experience trauma to the limb from a blow or falling down, or they may experience such injuries from competitive sports or recreational activities.
Sometimes, growth plate injuries happen when your child overuses a certain part of the body. Young children who specialize in a sport or activity and spend long hours training can overuse a specific limb or area of their bodies, causing growth plate injuries. This may be seen in:
- Gymnasts who practice for hours.
- Long-distance runners.
- Baseball pitchers.
Although most growth plate injuries happen during play or athletic activity, growth plates are also susceptible to medical disorders that can alter their normal growth and development.
Diagnosis of Growth Plate Injuries
Doctors diagnose growth plate injuries by:
- Asking about the pain and injury, including when the pain started and how the injury happened.
- Examining your child, which may include checking the injured area for tenderness, swelling, and deformity.
- Ordering x-rays.
Because growth plates have not yet hardened into solid bone, neither the structures themselves nor injuries to them show up on x-rays. Instead, growth plates appear as gaps between the shaft of a long bone (metaphysis) and the end of the bone (epiphysis). Therefore, a growth plate injury may not be apparent on an x-ray.
Other tests doctors may use to diagnose your child’s growth plate injury include:
- Magnetic resonance imaging (MRI).
- Computed tomography (CT).
Because these tests enable doctors to see the growth plate and areas of other soft tissue, they can help visualize the injuries and determine the type of growth plate injury.
Treatment of Growth Plate Injuries
Treatment for growth plate injuries depends on the type of injury. Treatment should start as soon as possible after injury and generally involves one or more of the following treatments.
Reduction of Fracture and Immobilization
The doctor puts the injured limb in a cast or splint after establishing normal alignment of broken bones to prevent movement of the area and allow the bone to rest. To help promote healing, your child or teen should limit any activity that puts pressure on the injured area.
If your child’s injuries cause the ends of the injured bones to be out of place (displaced), the doctor usually needs to set the bones or joints back in their correct positions. This procedure is called reduction of fractures. Depending on the type of growth plate fracture your child has, doctors can set bones by:
- Closed reduction, when the doctor aligns and sets the bone using their hands.
- Open reduction. Some growth plate injuries require surgery to align and set the bones. This procedure usually requires smooth metal pins to hold the bones in place without causing premature fusion of injured growth plates.
- After surgery, the doctor often uses a cast to immobilize the injured area. The cast is left in place until the injury heals.
- The need for surgery depends on the location and extent of the injury, its effect on nearby nerves and blood vessels, and the child’s age.
If the injury is serious or treatment is delayed, the growth plate fracture can interrupt the normal growth of the bone. For example, the bone may be crooked or slightly longer or shorter than expected. To help prevent problems with bone growth, your health care provider usually recommends follow-up appointments to monitor the bone for any changes in growth and development.
With immediate treatment, most children and teens recover without additional growth problems. How soon your child can return to their regular activities and sports depends on their recovery and the type of activity.
Strengthening and Range-of-Motion Exercises
Your child’s doctor may recommend exercises to strengthen the muscles that support the injured area of the bone after the injury has healed. Strengthening can help improve your child’s ability to move the joint in the way that it should. A physical therapist can work with your child to design an exercise plan.
Who Treats Growth Plate Injuries?
The following health care providers may help diagnose and treat growth plate injuries:
- Orthopaedists, who treat and perform surgery for bone and joint diseases.
- Occupational therapists, who teach ways to protect joints and perform activities of daily living.
- Pediatricians, who diagnose and treat children.
- Physical therapists, who specialize in movement and strengthening muscles.
- Sports medicine physicians, who treat musculoskeletal injuries from participation in sports.
Research Progress Related to Growth Plate Injuries
The NIAMS and the National Institutes of Health support research and scientists to seek better ways to diagnose and treat growth plate injuries and to improve patient outcomes. Examples of such work include:
- Investigating the factors that regulate growth plate chondrocytes. These cells are essential to growth at the ends of the bones.
- Exploring the molecular mechanisms regulating growth plate development and the mechanisms responsible for growth.
- Identifying predictors for premature closure of the growth plate following fractures. By predicting the injuries most likely to result in arrested growth, doctors could opt to treat them differently and more aggressively.
- Development of methods to regenerate musculoskeletal tissue by using principles of tissue engineering.