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Vital Signs: Developmental Dysplasia

Developmental dysplasia is a term used to describe a group of malformations in the hip joints of children.

By Sharron Sussman
Mar 1, 1999 6:00 AMMay 9, 2023 2:47 PM

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By Sharron Sussman

Little Gabrielle, three and a half, sat mutely on the examining table, watching my every move. Her legs dangled over the edge of the paper-covered vinyl, revealing a right knee that protruded about an inch farther than the left.

"You can fix her, can't you, Doctor?" her mother asked anxiously. "She's my dancer."

"Her pediatrician was very concerned," I said, evading the question. In fact, her pediatrician had bypassed the formality of an orthopedic consult and brought the X-rays straight to my office door. Orthopedic surgery is rooted in a long tradition of preventing deformity in children. (Orthopedics comes from two Greek words meaning "straight" and "child.") A crooked tree braced to a post is the emblem of the American Academy of Orthopaedic Surgeons. As the twig is bent, so grows the tree.

I skimmed the meager entries in Gabrielle's chart, trying to figure out how the asymmetry of her legs had been missed for so long. She had been seen by our medical group for about two years; while generally healthy, she had had routine visits for sore throats, ear infections, and immunizations. How could her family have missed this?

"When did you first notice something was wrong?" I asked the mother, slipping an X-ray onto the light box.

"My sister noticed while watching a videotape we made at a birthday party last week. Gaby was wearing shorts, and in one shot from the back, I could see that her bottom was kind of tilted and that she limped a little. At first I didn't really see it. But my sister played the tape over and over, and then I could see what she meant."

The X-ray suggested that the problem had developed gradually. Gabrielle's right hip joint was perfectly normal, with the ball at the upper end of the thighbone, or femur, cupped securely in the deep, round hip socket. But the left hip socket was enlarged and slightly shallow. Worse, the round head of the femur wasn't centered in the socket but had slipped up toward the outer edge. It wasn't completely out of the socket, but it wasn't normal.

Gabrielle had a problem called developmental dysplasia, a general term for a group of malformations in the hip joints of children. Nobody knows what causes them. What we do know is that they are more common in girls than in boys, more common in children who were born feetfirst, and more common in children whose other family members have the condition. We also know that early detection makes dysplasia easier to treat. In this country, evaluation of the hips is an important part of examining newborns. Any hint of a click or a clunk during gentle maneuvers of a relaxed baby's joints demands a call to an orthopedic surgeon. Treatment is usually a simple harness of straps that hold an infant's hips flexed and separated. Within about six or eight weeks, the ligaments surrounding the hip tighten up for good.

I had no way of knowing what Gabrielle's examination had been like when she was a newborn. If the head of the femur had been completely out of the socket at birth, her bones would have been much more deformed. Bone is dynamic; it remodels to meet mechanical demands, so the immature socket would have conformed to the displaced ball. Most likely, Gabrielle had been born with slightly loose ligaments in her hips. As she began to walk, and especially after she grew taller and heavier, the increasing pressure on her hip joint would have caused the ball of the femur to start slipping out of place. No longer centered, the ball and socket would deform with growth. Eventually the ball could work its way completely out of the socket. This hip would most likely deteriorate, causing Gabrielle painful arthritis by the time she was in her thirties. It looked as if I was going to be seeing this child for a long time.

Gabrielle was easy to examine, but she never said a word. Out in the hall, I watched her walk and run so I could get a good look at her slight limp. When I asked her to stand on one foot, she had more trouble balancing on the left. And when she let me measure her legs and move them through a range of motion, I noticed a slight tightness in her left inner thigh and a subtle shifting of the hip when I moved her thigh back and forth.

I asked her mother a few more questions, mostly to ease into telling her what she didn't want to hear. "It's not exactly an emergency," I said, "but I want to bring Gabrielle into the hospital and get that hip back where it belongs. Within a week or so."

"Will she need surgery?" she asked.

"Yes, she will," I said. "But I don't know yet how big an operation. And there'll be some time in a cast too."

Three days later, Gabrielle was back in my examining room with her father, mother, and two sisters. Once again I put up the X-ray. The difference between her two hip joints was easy to show. The hard part was explaining the treatment. Because the bony structure was close to normal, I told them, it was possible that a simple manipulation could relocate the ball in the socket. It might be necessary to cut the tight tendon at the inner thigh. But I might have to perform a more invasive operation, cutting through the muscle layers to see the joint directly and clear away any tissue obstructing the socket. Either way, Gabrielle would have to spend time in a cast stretching from her waist to her ankle. It would hold the hip in the correct position until the soft tissues healed enough to do it themselves. Then she would have to wear a brace for at least a year. In spite of all this, the hip could migrate back out of the socket, even years after surgery. That would mean another operation, possibly cutting bone. Gabrielle would need follow-up visits until she had finished growing.

Her parents turned and looked at each other. They seemed to take a synchronized deep breath. After a moment, the father turned back to me. "Would all this have been necessary if we had noticed it sooner?" he asked.

I told him we couldn't know for certain. "If she were as young as her six-month-old sister, she'd be easier to treat. But after she was a year old, it would have been the same story, although it's easier to carry around a one-year-old in a cast than a three-year-old!"

He smiled weakly.

Gaby was admitted to the hospital a week later, and the cast technician and I set up traction, using a set of light weights and pulleys to draw her legs gently down and apart, gradually stretching the soft tissue. The nurses said Gaby talked all the time, but she never said a word to me.

In the operating room a few days later, I could see that traction had helped. But with Gabrielle anesthetized to allow her muscles to relax fully, the tendon in her groin remained tight. So I painted the area with iodine, made a tiny incision, and cut the tendon with a small scalpel. That, I hoped, would free up movement in the joint. Two stitches and a Band-Aid completed the surgery. Next, with the help of a fluoroscopic X-ray viewer, I flexed and rotated her thigh until the ball appeared well seated in the socket. With the joint in this position, I gently rocked the hip back and forth. It did not shift. I held Gabrielle's legs in position while the technician applied the fiberglass cast that would stabilize her hip.

Gabrielle recovered easily from the anesthetic, as children usually do. We kept her in the hospital a couple of days to be sure the cast was comfortable and to trim any rough edges, then she was discharged.

At her one-week postop visit, Gabrielle and her X-rays looked fine. Five weeks later, a new set of X-rays showed that the hip was still in good position, so we cut the cast down to midthigh length. This would allow Gaby to crawl and move her knees. I ordered a light brace to hold her hip in position after the cast came off.

When the family came back for final cast removal, everyone's spirits were high. Gaby had gotten her "land legs" back in a hurry. They brought me a snapshot of her standing and smiling in her shortened cast. "Is this you?" I asked her. She looked up at me and said nothing. She held her mother's hand tightly as the loud, buzzing cast saw cut away. She didn't cry or complain as the brace was fitted. Then she headed home with her parents to celebrate--and to take a bath.

When I saw the next X-ray three weeks later, my heart sank. With the little extra motion allowed by the brace, and the stresses of walking on the hip again, the ball had slipped right back to where it had been before. I would have to go back to the operating room and open up the hip socket to clear away whatever was preventing normal joint fit.

As I carried the films into the exam room, Gabrielle's parents read my face before I even started to speak. I reassured them that what we had tried had been smart, the least-invasive strategy. But that approach hadn't solved the problem in Gaby's hip. I felt terrible. There was a long silence.

"When she's all healed, this can still come out as well as we hoped?" asked the father.

"Yes, of course," I said. "This is a setback, not a disaster. We haven't lost anything except a little time."

Two weeks later, I cut into the outer front of Gabrielle's left hip. I separated layers of muscle and tendon down to the capsule, the bag of ligament and fibrous tissue that holds the joint together. The capsule was abnormally formed. Its lower part was thick and tight, and the upper part, where the ball pressed against the socket, was baggy. I cut away the thickened tissue and tightened the baggy upper part. I tailored the tissue to fit the joint, as a seamstress might cut fabric to fit a curve. When I gently rotated Gaby's thigh inward, the ball fell into the socket with no resistance. An assistant held the thigh in position while I finished suturing. After that, when I wiggled the hip gently, it no longer tried to move out of position. I let the muscles and tendons fall together and closed the wound. Then I held the hip where I wanted it while my assistant put on the cast.

Gaby was in her long cast for eight full weeks before she was allowed to walk in a brace. She was as stiff as a board when I finally let her spend a little time out of the brace, shortly after her fourth birthday. Her X-rays continued to show a hip sitting normally in the socket. As the muscles adapted, her motion slowly returned to normal, and by the time she was due to start kindergarten, she was wearing the brace only at night.

Just before she started school, I examined Gaby again. That was a red-letter day for me. I watched her walk, then checked her motion and leg length and her X-rays. Everything looked great. "Your daughter's not out of the woods yet," I told her mother. "She won't really be until her growth is complete. I want to see her for new X-rays in three months, and after that maybe we can go to every six months or a year between visits." I paused and took a deep breath. "But I think she can stop using the brace altogether now." She smiled. I smiled. Gaby smiled, too, head down.

"I think that Gabrielle has something to say to you," her mother said. Gaby looked down at her knees, then back up at me. "Thank you, Dr. Sussman," she said in a clear voice. She had an enormous smile. I bent down and got a big hug.

I have a collection of snapshots Gaby's parents have mailed to me over the years. Some are group photos of the whole family. Most are just Gabrielle--in soccer shorts, in a pink ballet tutu. And there's one special picture of my former patient in a cheerleader's uniform: she's sitting on the ground with her legs folded under her. Her left hip has to be working pretty well to do that.

Congenitalhip dysplasia information from the Chiropractic Radiology WebpageCongenitaldislocation of the hip from ADAM SoftwareDevelopmentalDysplasia of the Hip from The Pediatric Bulletin

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