Developmental dysplasia of the hip (DDH) involves abnormal development of the hip joint, which typically involves underdevelopment of the acetabulum (hip socket) and instability of the femoral head. There is a tendency for subluxation or dislocation. These structural abnormalities can persist into adulthood and lead to weakness, recurrent subluxation or dislocation, abnormal gait and early degenerative changes.
DDH is either picked up during newborn examinations or later when the child presents with hip asymmetry, reduced range of movement in the hip, or a limp.
Risk Factors
Key risk factors for DDH include:
- First-degree family history
- Breech presentation from 36 weeks onwards
- Breech presentation at birth (after 28 weeks gestation)
All newborns with any of these risk factors should have an ultrasound to detect DDH (even if examination is normal).
Screening
DDH is screened for at the newborn examination at birth and at 6-8 weeks of age. Findings on examination include:
- Different leg lengths
- Restricted hip abduction on one side
- Significant bilateral restriction in abduction
- Difference in the knee level when the hips are flexed
- Clunking of the hips on special tests
There are two special tests used to check for DDH:
- Ortolani test
- Barlow test
The Ortolani test is performed with the baby on their back with the hips and knees flexed. Palms are placed on the baby’s knees with thumbs on the inner thigh and four fingers on the outer thigh. Gentle pressure is used to abduct the hips, and pressure is applied behind the legs with the fingers to see if an already dislocated hip will clunk back into place.
The Barlow test is performed with the baby on their back, hips adducted and flexed at 90 degrees, and knees bent at 90 degrees. Gentle downward pressure is placed on the knees, through the femur, to see if the femoral head can be displaced or dislocated posteriorly.
Clicking is a common examination finding and is usually due to soft tissue moving over bone. When this is the cause, an ultrasound will be normal. Isolated clicking without other features usually does not require an ultrasound unless there are other concerns. Clunking is more likely to indicate DDH and requires an ultrasound.
Diagnosis
Ultrasound is the initial investigation of choice in younger infants.
X-rays can also be helpful, particularly for older infants (4-6 months).
Management
Treatment typically involves a Pavlik harness if the baby presents at less than 6 months of age. The Pavlik harness is fitted and kept on continuously, with adjustments as the infant grows. The aim is to hold the femoral head in the correct position to allow the acetabulum to develop a normal shape. It keeps the infant’s hips flexed and abducted. It is removed when the hips are more stable, usually after 6-12 weeks.
Surgery or other bracing may be required if the harness fails or the diagnosis is made after 6 months of age. After surgery, a hip spica cast is used to immobilise the hip for a prolonged period.
Last updated July 2026
Now, head over to members.zerotofinals.com and test your knowledge of this content. Testing yourself helps identify what you missed and strengthens your understanding and retention.
