Pediatrics at HSS

Common Leg Problems in Children

Common Leg Problems in Children

Common Leg Problems in Children

Have you ever been concerned about a young child who appears to have knock-knees or bowlegs? It turns out that a lot of little kids’ legs aren’t perfectly straight, and most of the time it’s a normal part of their growth and development. Dr. John Blanco, a pediatric orthopedic surgeon at Hospital for Special Surgery, says the alignment of most kids’ legs straightens out by the time they’re seven years old.

“In young children, it’s generally nothing to worry about,” he explains. “Babies are born with a bowlegged appearance, but by the time they’re 18 months old, their legs become straight. Then as they grow, from age 18 months to three or four years old, most kids’ legs have a knock-kneed appearance, and that’s normal as well.”

It’s also not uncommon for kids to appear bowlegged when they start walking, and their legs usually look this way until around age two. Dr. Blanco says in general, children don’t develop normal leg alignment until they’re five to seven years old. Even then, many kids’ legs aren’t perfectly straight and some variation is normal.

When to See a Pediatric Orthopedic Surgeon

Parents often bring a child to Dr. Blanco because they’re worried about the appearance of their youngster’s legs. Pediatric orthopedic surgeons are specialists in childhood bone growth and development. “We see a lot of kids in the range of normal, and many parents just need reassurance. A family should never feel bad about bringing their child to a specialist for a second opinion.”

Some detective work may be in order to determine if poor leg alignment will resolve spontaneously on its own or if treatment may be needed. Sometimes a pediatric orthopedic surgeon will see a child for follow-up visits over several months to see how growth is progressing. The doctor may order x-rays and blood tests to make sure an underlying medical condition isn’t affecting bone growth. In the event there is a problem, the sooner it’s diagnosed and treated, the better.

When should parents see a specialist? “We’re concerned when a young child has a severe bowleg deformity that seems to be getting worse and worse by age two. As for knock-knees, if a child’s legs still appear this way at age nine, they may not be following normal bone growth patterns and treatment may be recommended. Any child who is limping or experiencing leg pain should also see a doctor,” Dr. Blanco says.

Fortunately, very good minimally invasive treatments for mild to moderate knock-knee or bowleg deformities can correct the problem, Dr. Blanco says. “The trick is to bring the child in early, when there’s still time to do a minimally invasive technique. If a child with severe bowlegs is older than five or six, for example, it often isn’t possible to treat with bracing or a minimally invasive technique and a bigger surgery will be needed.”

Treatment is not only important to improve the appearance of a child’s legs; it also enables the youngster to avoid problems later on. “Poor leg alignment puts significant stress on a joint, causing the cartilage to wear out,” Dr. Blanco explains. “So by the time someone is in their 30s or 40s, they may have pretty bad knee arthritis. Imagine if the front end of your car were out of alignment and your tires wear unevenly. The same thing happens to your knee joints.”

Leg Length Discrepancy

Although not as common as bowlegs or knock-knees, a leg length discrepancy is another condition that pediatric orthopedic surgeons treat. A slight variation in leg length isn’t all that rare and usually doesn’t cause problems. But when the difference starts approaching an inch or more and one leg is visibly shorter than the other, it can be hard on a child. It can affect balance and the way a youngster walks. It may eventually lead to pain in his lower back, knees or hips.

The difference can be a couple of inches, or even more, causing a noticeable limp if the child doesn’t wear a shoe lift. The good news is that pediatric orthopedic surgeons have a variety of treatments to lengthen the shorter leg, or shorten the longer leg.

The goal of any treatment is to attain equal leg length when the child is finished growing. “I always tell parents it’s not the difference at age three that’s most important. I care about what the difference will be when the child becomes a teenager and finishes growing,” Dr. Blanco explains. A pediatric orthopedic surgeon has the specialized training and expertise to predict what the leg length discrepancy will be when the child’s growth is complete. That information is vital to develop an appropriate treatment plan.

A youngster can be born with a leg length inequality, or it can result from an infection or injury. Sometimes a fracture that’s improperly treated can cause one leg to be shorter than the other, especially if the child’s growth plate is involved. The growth plate is an area of smooth cartilage at the end of the body’s long bones, and this is where growth occurs.

Pediatric orthopedic surgeons are the best doctors to treat a childhood fracture. “Just like you wouldn’t bring a child with an ear infection to an adult internal medicine doctor, you shouldn’t bring a child with a fracture to the orthopedic surgeon who performed his grandmother’s hip replacement. Our treatment of kids’ fractures is much different from the way adult fractures are treated.”

Dr. Blanco says prompt treatment of a child’s fracture is essential because there’s only a narrow window of time to make sure the bone is in the best position to heal correctly. “The biggest problem we see is a child who was brought to an adult orthopedic surgeon who may or may not understand the nuances of how a child’s fracture needs to be treated. That delay in treatment can potentially lead to poor results.”

Advances in Treating Leg Length Discrepancy

When a youngster has one leg that’s shorter than the other, a number of treatment options are available. The latest advance is a magnetic lengthening rod that is implanted into the shorter bone. An external magnet is placed on the child’s leg several times a day to lengthen the rod a tiny bit at a time. This enables the bone to get longer and longer until the short leg catches up to the longer leg and they are both the same length.

“Being able to address orthopedic issues affecting kids is very rewarding,” Dr. Blanco says. “Successful treatment of a leg length difference or other bone deformity makes a really big impact in their lives. It changes the way they think of themselves, their self-confidence, their ability to play sports, even the way they’ll function over the next 40 or 50 years. It’s pretty amazing.”