Babies whose legs are swaddled tightly with the hips and knees straight are at a notably higher risk for developing DDH after birth.
About
- 1 or 2 in every 1,000 babies have DDH that needs treating.
Aetiology
- The hip is a "ball-and-socket" joint.
- Hip joint has not formed normally
- Ball is loose in the socket and may be easy to dislocate.
- Developmental dysplasia (dislocation) of the hip (DDH)
Risks
- Girls, First-born children
- Breech delivery: ultrasound DDH screening of all female breech babies.
- Family history of DDH (parents or siblings)
- Oligohydraminos (low levels of amniotic fluid)
Classification
- Dislocated. Most severe. The Head of the femur is completely out of the socket.
- Dislocatable. Head of the femur within the acetabulum, but can easily be pushed out of the socket during a physical examination.
- Subluxatable. Mild cases of DDH. The Head of the femur is simply loose in the socket. During a physical examination, the bone can be moved within the socket, but it will not dislocate.
Clinical
- Screening hip exam at birth and 6-8 weeks
- Seen from birth to 1st year of life with legs of different length
- Uneven skin folds, Less Immobile or flexibility on one side
- Limping, toe walking, or a waddling, duck-like gait
Screening Ultrasound Criteria
- Hip feels unstable
- Family history of childhood hip problems
- Breech birth
- Twins or a multiple births
- Born prematurely before the 37th week of pregnancy
Differentials
Investigations
- X-rays and other regular follow-up monitoring are needed after DDH treatment until the child's growth is complete.
- USS: see above
Complications
- Damaged hip joint with pain and osteoarthritis by early adulthood.
- Difference in leg length or a "duck-like" gait and decreased agility.
Management
- The earlier it is diagnosed the easier it is to treat. Learn to swaddle properly can be helpful to prevent it. If detected at birth then consider Pavlik harness for 1-2 months or brace. This keeps the femur in the socket and helps strengthen ligaments. Normal care can continue.
- Diagnosis 1-6 months: Use harness or brace as above for 6 weeks then intermittent for 6 weeks. Sometimes the hip can be reduced gently into proper position, and then a body cast (spica cast) placed to hold the bones in place. This procedure is done while the baby is under anaesthesia.
- Diagnosis: 6 months to 2 years. Treat with closed reduction and spica casting. Skin traction may be used before repositioning which prepares the soft tissues around the hip for the change in bone positioning. If a closed reduction procedure is not successful then open surgery is necessary. In this procedure, an incision is made at the baby's hip that allows the surgeon to clearly see the bones and soft tissues and then reduced and a spica cast is usually applied to maintain the hip in the socket.
- Even after proper treatment, a shallow hip socket may still persist, and surgery may be necessary in early childhood to restore the normal anatomy of the hip joint.
References