Diseases & Conditions
Growth plate injuries
The growth plate is the area of growing tissue near the end of the long bones in children and adolescents. Each long bone has at least two growth plates, one at each end. The growth plate determines the future length and shape of the mature bone. When growth stops during adolescence, the growth plates close and are replaced by solid bone.
Growth plate injuries occur in children and adolescents because the growth plate is the weakest area of the growing skeleton, weaker than the nearby ligaments and tendons that connect bones to other bones and muscles. In a growing child, a serious injury to a joint is more likely to damage a growth plate than the ligaments that stabilize the joint. An injury that would cause a sprain in an adult can be associated with a growth plate injury in a child.
About 15 percent of all childhood fractures involve injuries to the growth plate. They occur twice as often in boys as girls, with the greatest incidence among 14- to 16-year-old boys and 11to 13-year-old girls. Older girls experience these fractures less often because their bodies mature at an earlier age than boys. As a result, their bones ﬁnish growing sooner, and their growth plates are replaced by stronger, solid bone.
About half of all growth plate injuries occur in the lower end of the outer bone of the forearm at the wrist. These injuries also occur frequently in the lower bones of the leg and in the upper leg bone or in the ankle, foot, or hip bone.
While growth plate injuries are usually caused by an accident such as a fall or a blow, chronic injuries can also result from overuse. For example, gymnasts, long-distance runners, or baseball pitchers can all have growth plate injuries. Most growth plate injuries in children are caused by falls, usually while running or playing on furniture or playground equipment. Competitive sports, such as football, basketball, softball, track and ﬁeld, and gymnastics, account for a third of all growth plate injuries. Recreational activities, such as biking, sledding, skiing, and skateboarding, make up another ﬁfth of all growth plate fractures, while car, motorcycle, and all-terrain-vehicle accidents accounted for only a small percentage of fractures involving the growth plate.
Whether an injury is acute or due to overuse, a child who has pain that persists or affects athletic performance or the ability to move or put pressure on a limb should be examined by a doctor. A child should never be allowed or expected to work through the pain. Children who participate in athletic activity often experience some discomfort as they practice new movements. Some aches and pains can be expected, but a child’s complaints always deserve careful attention. Some injuries, if left untreated, can cause permanent damage and interfere with proper growth of the involved limb.
Although many growth plate injuries are caused by accidents that occur during play or athletic activity, growth plates are also susceptible to other disorders, such as bone infection, that can alter their normal growth and development.
Child abuse also can cause skeletal injuries, especially in very young children who still have years of bone growth remaining. One study reported that half of all fractures due to child abuse were found in children younger than age one, whereas only two percent of accidental fractures occurred in this age group.
Injury from extreme cold, such as FROSTBITE, can also damage the growth plate in children and result in short, stubby fingers or premature degenerative arthritis. Both radiation and chemotherapy used to treat certain cancers in children may damage the growth plate. The same is true of the prolonged use of steroids for rheumatoid arthritis.
Children with certain neurological disorders that result in sensory problems or muscular imbalance are prone to growth plate fractures, especially at the ankle and knee. Similar types of injury are seen in children who are born with insensitivity to pain. In addition, the growth plates are the site of many inherited disorders that affect the musculoskeletal system. Scientists are just beginning to understand the genes and gene mutations involved in skeletal formation, growth, and development. This new information is raising hopes for improving treatment of children who are born with poorly formed or improperly functioning growth plates.
After learning how the injury occurred and examining the child, the doctor will use X rays to determine the type of fracture and decide on treatment. Because growth plates have not yet hardened into solid bone, they do not show on X rays but appear as gaps between the shaft of a long bone and the end of the bone. Because injuries to the growth plate may be hard to see on X ray, an X ray of the noninjured 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.
For all but the simplest injuries, the doctor may recommend that the injury be treated by an orthopedic surgeon or a pediatric orthopedic surgeon. Treatment should be started as soon as possible after an injury, and it generally involves a mix of the following:
• Immobilization The affected limb is often put in a cast or splint, and the child must 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 hand or during surgery. After the procedure, the bone will be set in a cast to enclose the injured growth plate and the joints on both sides. The cast is left in place for between a few weeks to two or more months. 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 followup Evaluation includes X rays of matching limbs at three- to six-month intervals for at least two years. Some fractures require periodic evaluations until the child’s bones have ﬁnished growing.
Most growth plate fractures heal without any lasting problems. However, if the injury was severe and the blood supply was 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 stunted growth is higher. An open injury in which the skin is broken carries the risk of infection, which could destroy the growth plate.