Hip dysplasia

Hip dysplasia happens when the ball (femoral head) and socket (acetabulum) of the hip joint don’t fit together as they should. The socket can be too shallow, so it doesn’t hold the ball firmly in place. This makes the hip less stable and, in severe cases, the ball can slip out of its socket. 

In babies and infants, specialists call this developmental dysplasia of the hip (DDH). Most people are born with the condition, but specialists may also diagnose it in the first few months of life. Some people only discover they have hip dysplasia as teenagers or adults, because symptoms can take time to appear. 

Routine baby checks sometimes miss DDH, or specialists may mistake its symptoms for another condition. Adolescents can also develop certain types of hip dysplasia after a growth spurt. 

The good news is that once specialists diagnose the condition, they can provide effective treatments that improve comfort and restore stability and movement.

The exact cause of hip dysplasia isn't known. It's thought the condition typically develops around the time of birth because at this point the hip joint is made of soft cartilage that is yet to harden into bone. 

If the ball isn't positioned firmly in the socket, the socket won’t form around it properly. This leaves it shallow. A shallow socket can also occur if the ball of the hip joint moves out of position when the space in the womb becomes more limited in the weeks leading up to birth.

Several factors are believed to increase the likelihood of a child developing the condition. These include:

• Family history: In some cases, there is a genetic link where a parent or other close relative has DDH.
• First-born babies: First-born babies fit tightly in the womb, unlike subsequent babies.
• Sex: Hip dysplasia is more common in girls. This may be due to anatomical differences in the female pelvis and the tendency of girls to have looser ligaments than boys.
• Breech position: If the baby is in the breech position during pregnancy, there's a chance this can impact the way their hips develop.

If you’ve been diagnosed with hip dysplasia or you want confirmation of the condition, you can book an appointment with an orthopaedic consultant who specialises in this area. Your consultant will request any necessary imaging tests and take you through the available treatment options for hip dysplasia. They’ll create a treatment plan and recommend the most effective approach for you.

Pavlik harness 
The Pavlik harness is a fabric splint for children. It secures the child’s hips in a stable position and strengthens the ligaments around the joints. The harness promotes natural movement and should be worn constantly for one to two months. The orthopaedic team can make any necessary adjustments during that time. We’ll advise you when to start phasing the brace out and when it can be removed. 

Surgery 
If the harness doesn't work or your child is diagnosed at a later date, your consultant may recommend surgery. The procedure could be closed reduction or open reduction. Both involve placing the ball of the hip joint back into the hip socket. 

Closed reduction 
This is a common procedure carried out on babies aged six to 24 months. It takes place after an arthrogram, which is where a dye is inserted into your baby's hip joint to produce detailed X-ray images. The closed reduction procedure takes place under general anaesthetic, and the surgeon will make a small opening in the groin. 

They’ll then surgically release the tendon in this area, which is known as the adductor tendon. This tendon is a band of tissue that runs between the pelvis and the knee, connecting the muscle to the bones. Its role is to stabilise the hips and help to move the legs together. 

The adductor is usually very tight, so the surgeon surgically cuts the tendon to release it. This is known as an adductor tenotomy, and it relieves the pressure on soft surfaces of the hip and helps to keep the ball in the socket once the procedure is complete. 

The tendon heals quickly afterwards. Once the tendon is relaxed, the surgeon will gently move the ball at the top of your baby's thigh bone (the femoral head) back into its socket (the acetabulum). 

Open reduction 
Open reduction surgery to treat developmental dysplasia of the hip (DDH) in children is usually carried out if closed reduction hasn't worked. As with closed reduction surgery, the surgeon begins the procedure by releasing the adductor tendon. 

They then make an incision at the front of the hip to access the hip joint. They’ll clear out the tissue that might be causing the blockage between the ball and the socket. The surgeon manipulates the ball into the socket, and the surrounding muscles are then repaired using sterile dissolving stitches. Restoring and tightening the muscles increases the likelihood of the hip joint remaining in place. 

Spica cast 
After both open and closed reduction surgery, your child will be placed into a special hip cast known as a spica cast. This usually goes from the upper chest and runs down the hips and leg, finishing at the ankle. It keeps the joint in place, allowing it to strengthen, as well as stabilising the affected area. The constant contact between the ball and socket encourages the socket to grow into the correct shape. 

The cast is changed every six weeks and may need to be worn for up to six months. You or your child will be seen at our outpatient clinic for a follow-up appointment six to eight weeks after surgery. Our orthopaedic team will remove the spica cast and take an X-ray to make sure the cast is working and the hip is healing as expected. Your doctor will confirm whether the cast needs to be worn for longer at this point. 

Once the cast is removed, children usually start walking at their own pace within a few days, but it can sometimes take as long as a week or two. Physiotherapy may be needed too, but your doctor will provide you with advice about this. 

If you're an adult who's been diagnosed with hip dysplasia, any treatment or need for surgery will be based on the severity of your condition. Should surgery not be necessary, your hip consultant may suggest non-steroidal anti-inflammatory drugs for pain relief and lifestyle changes such as weight management and gentle exercise. 

If the pain persists, your consultant may recommend that you undergo either a periacetabular osteotomy (PAO) or a total hip replacement (THR). Ignoring the pain will cause further degeneration of the joint and could reduce the possibility of corrective surgery in the future, so speak to a medical professional as soon as you can. 

A PAO involves repositioning the hip socket and screwing it in place to restore and maintain normal function. A THR means removing your damaged hip joint and replacing it with an artificial one, known as a prosthesis. Your consultant will recommend the most effective procedure for you.