If you’ve taken your baby to the pediatrician, you might have noticed the doctor placed the baby on their back and gently moved their legs in and out in a circular motion, holding them by the knees.
This is a way to check for signs of developmental hip dysplasia.
“Hip dysplasia means that something about the hip joint developed incorrectly, often for reasons we don’t know,” says UNC Health pediatric orthopedic surgeon Anna Vergun, MD. “It can mean a range of things, from a full hip dislocation, or something like the socket is shallow and doesn’t fully cover the ball of the joint, but the hip is stable and does not dislocate.”
It can be alarming to hear that your new baby’s hip hasn’t developed, but there is treatment. Dr. Vergun explains six things you need to know about hip dysplasia.
1. It’s often diagnosed by a pediatrician at birth or at an early appointment.
Pediatricians are trained to check a baby’s hips for any signs of dysplasia.
“Sometimes parents can pick it up, but it can be really subtle,” Dr. Vergun says. “It can feel like a ‘click,’ like something snaps inside when the hip moves.”
A click is different than a “clunk,” Dr. Vergun says, noting that the more intense feeling of the hip changing its position suddenly might signify a dislocation. If you’re concerned about any noise, talk to your child’s doctor.
Here’s some good news: Hip dysplasia will not make your baby cry.
“It’s not painful, so a child crying in pain will not alert a parent to the problem,” Dr. Vergun says. “That’s why children are screened by their pediatrician.”
Babies are screened a few times by their pediatrician in case signs of dysplasia are subtle; for example, uneven fat roll lines on the back of the thighs or buttocks can signal dysplasia. To diagnose the condition, your pediatrician will order an ultrasound if your child is younger than 6 months or an X-ray if your child is older than 6 months.
2. Developmental hip dysplasia is more common in girls.
Sometimes, hip dysplasia is the result of a neuromuscular disease, such as cerebral palsy or spina bifida. Most babies with hip dysplasia do not have another diagnosis and otherwise develop normally.
“It’s more common in firstborn females for some reason, and it’s more common on the left hip than on the right, probably because of how a baby is positioned in the birth canal,” Dr. Vergun says. “Family history of hip dysplasia and having a breech birth also can increase the risk.”
3. Certain swaddles and carriers increase the risk of hip dysplasia.
In most cases, a baby is born with hip dysplasia, but it also can develop over time. Swaddles and carriers—typically older styles—that bind the legs close together can raise the risk.
“Traditionally, in the 1950s and 1960s, babies were swaddled by tightly wrapping their legs and arms up together, and this has been identified as a clear cause of hip dysplasia,” Dr. Vergun says. “Most swaddles on the market now just wrap the arms so that the knees can be free and apart, which is helpful for the hips.”
Beware of sling-like carriers that wrap the legs together tightly and restrict hip movement.
“The best carriers help the baby into a frog position, where the hips are flexed and the knees are as wide apart as they can get,” Dr. Vergun says.
The International Hip Dysplasia Institute maintains a list of companies that provide hip-friendly products.
4. The most common treatment for hip dysplasia is noninvasive.
Some hip instability that’s noticeable at birth resolves on its own in a few weeks. If your child’s doctor recommends treatment for hip dysplasia, your baby will typically start by wearing a Pavlik harness, which is a brace that holds the knees apart and the hips flexed. Straps go around the feet and the shoulders.
“They still have some movement, because we want their joints to move, but with hip dysplasia, we want the joints to move within a certain range that helps the hip back into the socket and helps the cartilage to better develop,” Dr. Vergun says.
While this treatment is noninvasive and not painful for the baby, it’s not easy.
“The harnesses can be frustrating, because there are a lot of straps, they’re hard to wash, and we ask parents to keep their babies in them for 23 hours a day,” Dr. Vergun says. “They can interfere with car seats and nursing until you learn the tricks of what works. That can be overwhelming and emotional, especially at a time when you’re already learning a lot of new things with your baby.”
Most babies have to wear a Pavlik harness for at least 12 weeks, but it’s usually not possible to predict how long your baby will be in the harness based on the severity of their case; Dr. Vergun says she’s seen babies with extreme cases of dysplasia have resolution fairly quickly, while some babies with mild cases might wear one for a year with no effect.
5. There are surgical options for developmental hip dysplasia.
If a baby’s hips do not respond to bracing, there are surgical options.
“First, we can try a closed reduction, where we put the baby to sleep and manually try to put the hip back into the socket,” Dr. Vergun says. “If that doesn’t work, we’d move on to open surgery.”
During open surgery for hip dysplasia, the doctor may have to remove or rearrange tissue that’s preventing the ball from fitting in the socket. They may have to reshape the bone around the hip to ensure that the joint fits together and stays. They reposition the hip, and then the baby is in a spica cast, which immobilizes the legs and the hips, for six to 12 weeks.
Different surgeons may want to pursue open surgery at different points in a baby’s development, so talk to your doctor about when this procedure might be recommended.
Any time a dislocated hip is put back into the socket, with or without surgery, it carries the risk of avascular necrosis, when bone tissue dies because of lack of blood flow; putting the bone in the socket changes the blood supply to the head of the hip joint. Providers have developed techniques to minimize this risk, but nothing so far has eliminated it. Avascular necrosis can affect the shape of the hip and cause future pain, but these risks are similar to those of not treating hip dysplasia at all; untreated hip dysplasia can lead to pain, difficulty walking and early arthritis in the hip.
6. More treatment might be needed later in life.
Unfortunately, a single surgery is not always the end of the journey with hip dysplasia. Your child likely will have ongoing visits to monitor growth and placement of their hip.
“Because we still don’t really know what causes hip dysplasia, the story isn’t over until the child is done growing,” Dr. Vergun says. “Some hips do great, but some hips continue to grow abnormally and may need additional bracing or surgery to minimize pain in the future.”
A history of hip dysplasia also raises the risk of hip osteoarthritis later in life.
“I know it’s hard that there’s so much uncertainty with this, but one of the things that’s most reassuring is that this a joint that we have amazing answers for, with hip replacement surgery,” Dr. Vergun says. “A hip replacement surgery is one of the most successful surgeries throughout the world. In terms of success of the surgery and the ability to make a pain-free return to an active life, appendectomies are No. 1 and hip replacements are No. 2.”
Of course, the idea that your child might need a hip replacement in a few decades isn’t ideal, but Dr. Vergun says to consider it a worst-case scenario that’s still pretty good.
“The goal is to make it work with the child’s own hip, but the backup option is a good one,” she says.
If you have questions about your child’s development, talk to their doctor or find one near you.