When you think of growing bones, you might think they grow out from the center of the bone. But the long bones in the legs and arms grow from an area at either end of these bones called the physis, or more commonly, the growth plate. These areas produce new bone tissue and determine the final length and shape of bones in adulthood.
An injured growth plate might not do its job properly, which can lead to crooked or misshapen bones, limbs that are too short, or even arthritis. Fortunately, these occurrences are rare. With recognition and proper treatment, the vast majority of kids recover from growth plate injuries without any long-term consequences.
About Growth Plates
All long bones have an area called the epiphysis, which is the rounded end of the bone. The long, middle part (or shaft) of the bone is the diaphysis; the area where the bone gets wider at its end is the metaphysis.
In a growing child, growth plates sit between the metaphysis and the epiphysis. Growth plates are the developing tissues at the end of long bones that grows in length. Growth plates are made up of cartilage, a rubbery, flexible material (the nose, for instance, is made of cartilage).
When a child's bones have completed growing (or reached skeletal maturity), the growth plates ossify (harden) and cause the epiphysis to fuse together with the metaphysis, forming one complete bone.
Girls tend to reach skeletal maturity earlier than boys; their growth plates usually close around ages 13 to 15, while boys' growth plates close later, at around ages 15 to 17. However, before growth is complete, the growth plates are susceptible to fractures (breaks). An adult whose bones have finished growing might simply pull a muscle or a tendon after a fall. But in a child, that same fall could injure the growth plate.
Most of the time, growth plate injuries happen from falling or twisting. Contact sports, like football or basketball, or fast-moving activities like skiing, skateboarding, sledding, or biking, are common causes. Injuries can also happen from activities that require repetitive training, like gymnastics, track and field, or pitching a baseball.
Less common causes of injury include:
exposure to extreme cold
medical conditions that affect bone growth
medications that can affect bone growth, like treatments for arthritis or cancer
Signs and Symptoms
Signs and symptoms of a growth plate injury are the same as those for a broken bone, and include:
inability to put weight or pressure on the limb
pain or discomfort
inability to move the limb
If you suspect your child has a bone injury, try to give first aid until medical care can be provided:
Remove clothing from the injured area.
Apply an ice pack wrapped in cloth.
Keep the injured limb in the position you find it.
Place a simple splint, if you have one, on the broken area. The splint should be applied in the position of the injured limb to help keep it from bending or moving — do not try to move or straighten the limb. Splints can be made by using cardboard, a stack of newspapers, or anything firm, and can be padded with pillows, shirts, towels, or anything soft. Splints must be long enough to extend beyond the joints above and below the injury.
Get medical care, and don't allow the child to eat in case surgery is required.
A child with an open break (a bone protruding through the skin) and bleeding needs to have pressure applied to the bleeding area with a gauze pad or a clean piece of clothing or other material. Do not wash the wound or try to push back any part of the bone that may be sticking out.
After the child receives medical attention, make sure to elevate the area and apply ice packs or cold compresses for 20-minute intervals every few hours for the first 2 days after injury. This will help reduce pain and swelling. Over-the-counter pain or anti-inflammatory medicines may be given to ease discomfort.
In the emergency room or doctor's office, doctors will ask how the injury occurred and may perform some physical tests, like applying pressure to the bone or joint to see if it's unstable.
Because growth plates are cartilage, they may not show up on X-ray images. X-rays mainly show just the hard, calcium-containing parts of bones. But doctors can still tell a lot from an X-ray, including looking for swelling adjacent to the growth plates.
Treatment for growth plate injuries initially involves resting and not bearing weight on the affected limb. Most of the time this can be accomplished by wearing a cast, splint, or brace over the area to prevent movement. Many growth plate injuries are minor, and this may be the only treatment necessary.
Other times, if bones are displaced, they may have to be manipulated back into place through a gentle procedure called a reduction. If needed, a reduction will usually be done in the emergency room or operating room, after the child has been given some medication to lessen the pain. Afterward, the child may wear a splint or a brace to ensure that the bones do not move out of place.
In older kids or young children with complicated injuries, surgery might be needed to realign the bones. Surgical plates, screws, or wires might be used to secure the area so that the bone heals normally. After surgery, some kids will wear a cast during recovery.
After the fracture has healed, some kids might need physical therapy to help strengthen the area around the injury, restore normal movement if a joint (like the elbow) was affected, and make sure bones and joints are functioning normally.
Most kids who are treated for growth plate injuries do not have any long-term complications. However, follow-up care is important to make sure bones are healing and continuing to grow normally.