Clinical problem
A 2 year old girl presented to clinic with an abnormal walking pattern. She was the first child in the family. Pregnancy was unremarkable and the baby was delivered at term by normal delivery. There were no concerns after birth. She started walking at the age of 14 months. The parents noticed that her walking did not look normal. She tended to lean over to the left side when her left foot was on the ground. She did not appear to be in any pain and there were no other concerns.
Is your child experiencing similar symptoms? Consult Dr. Qureshi, for expert diagnosis and treatment.
Diagnosis
Clinical examination revealed a slight difference in the leg lengths with the left leg slightly shorter than the right leg. The left hip did not appear to move as freely as the right hip but did not appear to cause any pain when moved. The remainder of the examination of the legs was normal. Gait analysis demonstrated asymmetry of gait with leaning over to the left side when the left foot was on the ground.
A pelvic x-ray was requested. This demonstrated that the left hip was dislocated. The socket of the left hip had an abnormal shape. The ball at the top of the femur (thigh bone) was a different shape compared with the opposite normal hip. A diagnosis of left hip dislocation secondary to developmental hip dysplasia was made on the basis of the clinical history, examination findings and x-ray.
Developmental hip dysplasia is a condition which affects 1 in 500-1000 births. Known risk factors include breech presentation and a family history of hip dysplasia. However, in many cases like this patient there were no risk factors. The condition is more common in first born babies and girls.
The condition was discussed with the parents. If left untreated, the hip dislocation would result in a shorter leg with reduced function in childhood and progression to painful arthritis in adult life. The recommended treatment for hip dislocation in a child aged 2 years is surgery to correct the hip dislocation. The parents opted for surgical treatment for their child.
Treatment
The patient underwent surgery a few weeks after the clinic discussion. The first step in the surgery was an arthrogram to define the problem. The arthrogram is a dye injection study to outline the shape of the hip. This demonstrated that the ball could not be manually placed back into the joint and needed to be surgically opened.
The hip was accessed through a “bikini” incision in the groin crease which heals with a nice cosmetic result. Standard muscle releases were performed to enable the ball to be placed back into the socket. An arthrogram (dye injection study) confirmed that the ball was placed deep in the socket.
To reduce the tension in the hip and avoid damage to the soft cartilage ball of the hip joint, the femur (thigh bone) was shortened. The shortening reduces the muscle tension across the hip avoiding further damage to the ball once it is placed back into the socket. The femur shortening was done through an incision on the side of the thigh. 25mm of femoral bone was removed and kept for the pelvic osteotomy. The femur was fixed with a metal plate and screws. Slight rotation was introduced before fixing the femur with the plate. This was done to point the ball deeply into the socket and to make the hip more stable.
The socket in this case was shallow and abnormally shaped. This was corrected to stop the hip from dislocating again. A Dega pelvic osteotomy was done to correct the shape of the socket. Using x-ray guidance, the pelvic bone was divided above the socket using instruments resembling chisels. The pelvic bone was not completely divided. A small bridge of bone was left intact to act as a hinge. This allowed the “roof” to be levered down and create a deeper socket. The gap made by levering the “roof” down was filled with a wedge of bone fashioned from the femoral shortening. This bone wedge held the correction without the need for any wires or screws. After the pelvic osteotomy, the capsule of the hip joint was closed snugly to help keep the ball in the socket.
After the surgery was completed, a plaster cast hip spica was applied to the legs to keep the hip joint in position during healing. The spica cast also helps with pain relief for the child so that the child can be easily moved without disturbing the hip. At the time of surgery, an epidural catheter was inserted into the spinal canal for pain relief. A urinary catheter was inserted to help drain the bladder.
Is your child experiencing similar symptoms?
Consult Dr. Qureshi, for expert diagnosis and treatment.
Consult Dr. Qureshi, for expert diagnosis and treatment.
Outcome
After surgery the patient was observed on the ward for 48 hours. The epidural and urinary catheter were maintained for 48 hours for patient comfort. Blood tests were done on the first post-operative day and the results confirmed that the blood count was acceptable and a blood transfusion was not required. On the second post-operative day, the epidural and urinary catheter were safely removed and the child was comfortable. A 3d CT scan was undertaken which confirmed that the ball was placed in the socket. The child was discharged home on post operative day 2 with simple analgesia.
The child was seen in clinic at 1 week to check that the spica was fine and the parents were managing well. The child was next seen at 6 weeks when the spica was removed. The surgical sites were inspected and found to have satisfactorily healed. The x-ray showed the ball was in the socket. The family were advised to allow the child to mobilize freely in their own time. The child started walking again within 4 weeks.
The child was then seen at the following clinic time points – 6 weeks, 3 months, 6 months and 1 year following surgery. Hip movements and leg lengths were found to be symmetrical at each visit. The child was in no pain with full function. X-rays demonstrated excellent development of the hip with complete healing of the femoral and pelvic osteotomies.
At 13 months following surgery the femoral plate was removed. This was done as a day case surgery and the child was able to walk immediately after. The child was followed up annually with clinical assessments and x-rays. The pelvic x-ray at 4 years from surgery demonstrated symmetrical hip development with a round ball sitting in the socket adequately covered by the pelvic roof. The child continues to do well with active participation in sports and play without any discomfort or restriction in function.
