Developmental Dysplasia of the HIp (DDH)

Question 1

Define developmental dysplasia of the hip (DDH)

Answer 1

Disorder of hip joint development resulting in hip instability/subluxation/dislocation +/- acetabular dysplasia

Question 2

What is the purpose of neonatal screening for DDH and how is it performed?

Answer 2

• All neonates screened at 2-3days of life
• Done as early detection of DDH is important as it usually responds to conservative tx
• Done as part of routine examination of newborn
• Barlow’s and Ortolani’s manoeuvres
• Rescreened at 6wk check - different tests as these manoeuvres no longer work due to increased tone

Question 3

What are the identifying features of possible DDH at 6wk check?

Answer 3

1. Asymmetry of skin folds around hip
2. Limited abduction of hip
3. Shortening of affected leg

Question 4

What is the true prevalence of DDH?

Answer 4

1.3 per 1000 live births

Question 5

Describe the investigation pathway for DDH

Answer 5

1. Neonatal clinical exam
2. If abnormal - early hip US at 6-10wks and urgent orthopaedic appointment
3. If normal - examined again at 6wk check; suspect DDH do hip US (6-10wks); make orthopaedic appointment

Question 6

List the risk factors for DDH

Answer 6

1. Family hx
2. Female > male
3. Left hip > right hip
4. Race
5. Breech presentation

• If have 1 AND 5 - automatically progress to early hip US at 6-10wks even if newborn screening normal

Question 7

Define teratologic dislocation

Answer 7

A distinct form of hip dislocation associated with neuromuscular syndromes. The hip is dislocated before birth and it is much more difficult to treat.

Question 8

List the conditions associated with DDH

Answer 8

1. Torticollis (20%)
2. Metatarsus adductus (10%)
3. Talipes calcaneovalgus
4. Teratologic dislocation
5. Down syndrome

Question 9

What investigations should be performed if DDH suspected?

Answer 9

1. Age <6mths - hip US

2. Age >6mths - AP pelvis radiograph

Question 10

How is DDH managed?

Answer 10

1. Age <6mths = pavlik harness
2. 6-18mths = manipulation and closed reduction + hip spica plaster cast OR open reduction if closed fails +hip spica cast
3. 18-24mths = Trial of closed reduction OR open reduction +/- pelvic osteotomy + hip spica cast
4. Age 2-6yrs = open reduction +/- femoral shortening +/- pelvic osteotomy + hip spica cast

Question 11

List the complications of DDH

Answer 11

1. Early - inadequate reduction and redislocation
2. Intermediate - residual acetabular dysplasia; avascular necrosis
3. Late - early osteoarthritic changes