Developmental Hip Dysplasia

– The information has been reviewed by Dr. Liu King Lok

What is developmental hip dysplasia?

In healthy newborn babies, the top of the femur (which is the femoral head) should sit perfectly inside the hip socket (which is the acetabulum). If the baby has hip dysplasia or if the hip socket is too shallow that the femoral head is not held tightly in place, the femur can easily dislocate and detach from the hip socket.


What happens if developmental hip dysplasia is left untreated?

As the baby grows up, he/she might have leg length discrepancy or will be more prone to developing early degeneration of the hip joint. If the condition is serious, joint replacement will be required.


Is developmental hip dysplasia common in newborns?

According to previous research data, one out of every 1,000 newborns in Hong Kong suffers from this condition. Clinically, this condition has been on the rise in recent years.


High-risk factors


Risk is (times) higher than normal infants

Breech delivery: when a baby is born bottom first


Oligohydramnios: a deficiency of amniotic fluid


Female babies


Family history


First-born babies


Intrauterine growth restriction


Post-term pregnancy: the baby is born after 40 weeks



What are the symptoms of developmental hip dysplasia?

Generally speaking, babies do not feel pain, hence this condition is often easily ignored. Caregivers should pay extra attention to see if the baby has the following conditions:

  • Legs are different in length
  • Uneven skin folds on both thighs or buttocks
  • When changing diapers, the thighs cannot be fully spread to both sides, or the degree of spreading is asymmetric
  • Crawling with one leg
  • Abnormal standing posture, such as standing with the ankle of one foot lifting off the ground and the body being supported with toes
  • Abnormal walking gait, such as limping or walking on one of the toes


How to prevent developmental hip dysplasia?

Parents should arrange their newborns to undergo hip ultrasound examination before they are six weeks of age.

  • The Hong Kong Maternal and Child Health Center examines the hip joints for newborns, mainly by visual inspection and manual examination. However, these methods may not be effective enough to detect the hip problem. The most ideal way of diagnosis is ultrasound.
  • Countries such as Austria, Germany, Switzerland, the Czech Republic, and Mongolia have already implemented hip ultrasound screening for newborns. It is mandatory for all newborn babies to undergo hip ultrasound examination within six weeks from their date of birth. Research data shows that the number of cases of infants undergoing hip surgery in these countries experience a downward trend.


Be careful when swaddling newborns 

In recent years, swaddling has become increasingly popular. It is a practice of wrapping the baby with a blanket in a way that resembles the mother's womb. This helps calm and soothe the baby. However, the American Academy of Pediatrics has pointed out that parents must pay extra attention to safety when swaddling their babies. One of the key points is not to wrap the baby too tightly and not to forcefully straighten the baby's legs. This is to ensure the baby's legs can bend naturally. Especially for babies in high-risk groups, parents are best not to wrap them.


Treatment of developmental hip dysplasia

Early diagnosis allows newborns or young children to receive non-invasive treatments, helping them avoid the risks of undergoing surgery. 

0-6 Months

6 Months – 1.5 Years

1.5 Years – 5 Years


Pavlik Harness / Tubingen Splint

Close reduction / Surgical reduction / Hip spica cast


Pelvic osteotomy and hip spica cast

If the patient’s hip joint begins to degenerate and becomes painful, but the articular cartilage is still intact, patient can undergo peripheral acetabular osteotomy (PAO)

  • Non-invasive treatment, allowing hip joint to recover itself naturally
  • Must be worn 24 hours a day
  • Recovery time: around 2-3 months
  • By wearing it for 0-2 months, recovery rate can go up to around 90-95%
  • Hip reduction will be performed first, then the patient will be put in a cast from the chest to the heel 
  • Recovery time: around 3 months
  • Pelvic osteotomy will be performed first to reshape the shallow acetabulum (hip socket) to make it deeper so that it can accommodate the femoral head; after the surgery, patient will be put in a cast from the chest to the heel for about 5-6 weeks
  • Metal implant is not necessary for fixation
  • Recovery time: about 2 to 3 months
  • Pelvic bone reconstruction will be performed to move the shallow hip socket to a location within the hip area where it can support the most weight. Yet, this treatment method is more traumatic and much riskier.
  • Recovery time: about 3 to 6 months
  • If the patient’s cartilage is damaged, the hip joint must be replaced with an artificial one.

*If children are diagnosed after 5 years of age, surgery is not recommended. Treatment will only be required when the patient's hip joint begins to degenerate and becomes painful.


Case 1: 15-month-old baby had difficulty spreading her legs open

Mrs. Yeung recalled that when her daughter was a few months old, she felt something was wrong with her baby’s hip joint every time she changed the diapers. “Why can’t my daughter spread her legs open? Every time when I change her diapers, it’s always a struggle!” said Mrs. Yeung. She first consulted a pediatrician, but to no avail. It was until when she arranged her baby to undergo X-ray and ultrasound examinations, then she found out her baby had developmental hip dysplasia. However, at the time of diagnosis, her daughter was already 7 months old. She first underwent non-invasive treatment but it was ineffective, that’s when surgery was needed for her daughter. If this condition is left untreated, the baby’s gait and walking will be affected, which may even increase joint strain. 


Case 2: A 4-year-old girl’s walking gait was abnormal before surgery. Afterwards, she can even dance.

When the now 4-year-old Sumsum (the name has been changed) started kindergarten at 2 years old, the teacher told Sumsum’s mother that Sumsum’s walking gait was a bit abnormal and reminded her to pay close attention. “In fact, some relatives noticed this problem too, but the doctor said it wasn’t serious. At first, I thought she just had flat feet. But after receiving the teacher’s remarks, I brought Sumsum to an orthopedic doctor. X-ray examination showed that one side of her hip was dislocated and she had dysplasia in the other side of the hip. She had to be admitted to the hospital for surgery (pelvic osteotomy) right away!" recalled Sumsum’s mother.

After the surgery, Sumsum was in a cast from her chest to her ankle. This allowed her to keep her legs open for more than 2 months. “We were concerned about hygiene problems so we helped her clean every day. Also, we had to care for her skin as we were worried that her eczema condition would develop. It was a very tiring period for both Sumsum and me,” said Sumsum’s mother.

After having the cast removed, Sumsum continued to wear a brace for her treatment. Because of her long-term inactivity, Sumsum had to undergo several months of physiotherapy. Now Sumsum has recovered very well – not only can she walk normally, she can also dance. Yet, vigorous exercises such as ball sports, trampoline, calisthenics should still be avoided. Bad postures such as squatting and squatting are also not recommended for patients who recovered from their treatments.