Developmental dysplasia of the hip Flashcards
How common is DDH?
affects 1-3% of newborns - females are 6 times more likely to be affected
What are the risk factors for DDH?
- Breech presentation at or after 36 weeks
- FH
- Firstborn child
- Oligohydramnios
- High birth weight (>5kg)
- Congenital calcaneovalgus foot deformity
Rare in Afro-caribbeans
Which hip is DDH more common in ?
Left but 20% of cases are bilateral
How do you screen for DDH?
ULTRASOUND examination if:
- positive FH
- breech at or >36 weeks
- multiple pregnancy
BARLOW and ORTOLANI tests for all infants during the newborn check and six-week baby check
What should be included in the examination for DDH?
- Barlow test (dislocates an articulated femoral head)
- Ortolani test (relocates a dislocated femoral head)
- Check leg length symmetry
- Level of hips/knees during bilateral flexion
- Level of restriction of hip abduction in flexion
When is XR vs ultrasound used in DDH?
- Ultrasound - <4.5 months
- X ray - >4.5 months
US Graf technique is used to measure the depth and shape of the acetabulum. (F) shows femoral capital epiphysis.
After 5-6 months the femoral head ossifies and this can be seen on X-ray (shown below - ossifying right femoral capital epiphysis is reduced in size when compared to the normal left side)
What is the management of DDH?
- Most will self stabilise by 3-6 weeks
- Pavlik harness (dynamic flexion abduction orthosis) if <4-5 months
- Surgery in some cases
A 6-week old infant is reviewed in the GP surgery. He was delivered vaginally in breech position at 38+4 weeks gestation. There were no intrapartum complications. The newborn physical examination (NIPE) was otherwise unremarkable. His mother has a history of anaemia, asthma, and coeliac disease. Today, the infant appears happy and is progressing well along the 45th centile.
What investigation should the GP refer the infant for due to his history?
Ultrasound of pelvis after 6 weeks should be done on all infants born >36 weeks gestation to screen for DDH AND regardless of mode of delivery
What typw of harness can be used as initial management for DDH?
Pavlik harness
Why has DDH replaced CDH?
the condition is not always present at birth and does not always result in dislocation
What is the pathophysiology in simple terms?
Abnormal development of the hip joint.
In DDH, the femur does not fit securely into the acetabulum.
Usually the socket is too shallow, more like a saucer than the deep cup.
In an older child, what is seen on examination in DDH?
Waddling gait
Leg may appear shorter than the other
Positive Trendelenburg test - pelvis tilts towards the unaffected side when standing on the affected leg
Describe the Ortolani and Barlow maneouvres.
The Barlow manoeuvre is performed by adducting the hip while pushing the thigh posteriorly. If the hip goes out of the socket, it is called “dislocatable” and the test is termed “positive”.
The dislocation is confirmed by performing the Ortolani manoeuvre to reduce or relocate the hip. The hip being tested is abducted and gently pulled anteriorly. The sensation of instability in a positive Ortolani manoeuvre is the palpable and sometimes audible “clunk” of the femoral head moving over the posterior rim of the acetabulum and relocating in the cavity. The more poorly developed the acetabulum (and thus the more unstable the hip), the less pronounced the “clunk”. Audible high-pitched “clicks” without a sensation of instability have no pathologic significance.
