Developmental dysplasia of the hip

Previously called 'congenital dislocation' of the hip
Common features include:
- Dysplasia of the acetabulum
- Femoral neck anteversion
Apparent incidence depends on age
20 per 1000 neonates have clinical evidence of hip instability
Only one per 1000 have evidence of hip dislocation at 3 months

Congenital dislocation of the hip can present as:
- Neonate with hip instability
- Infant with limited hip abduction
- Toddler with a limp
- Adult with degenerative hip changes
All neonates should be screened for hip instability
Hips are flexed to 90 degrees and instability detected by:
- Reduction of dislocation by abduction and forward pressure (Ortalani's test)
- Dislocation of hip by adduction and backward pressure (Barlow's test)
Ultrasound my be useful but with a high sensitivity it results in significant over diagnosis
Plain x-rays not reliable until child is 3 months old
In infant diagnosis should be suspected if there is a limp
Examination may show limb shortening, extra thigh skin crease and hip external rotation
X-ray will show shallow acetabulum with underdeveloped femoral head

The aim of treatment are:
- To reduce the dislocation by traction or open reduction
- To maintain reduction by harness, cast, soft tissue release or osteotomy
Need to achieve stable congruous reduction without damaging the growth plate
The above aims can be achieved by
- Pavlick hip harness or Von Rosen splint in a neonate
- Traction in a infant
- Open reduction +/- osteotomy or acetabuloplasty in an older child

Baucher H. Developmental dysplasia of the hip (DDH): an evolving science. Arch Dis Child 2000; 83: 202.

Eastwood D M. Neonatal hop screening. Lancet 2003; 363: 595-597.

Harcke H T, Grisson L E. Pediatric hip sonography. Diagnosis and differential diagnosis. Radiol Clin North Am 1999; 37: 7870796.

Hubbard A M. Imaging of pediatric hip disorders. Radiol Clin North Am 2001; 39: 721-732