Developmental Dysplasia of the Hip (DDH)

Question 1

pathology

Answer 1

dislocation/ subluxation of the femoral head during the perinatal period
affects the subsequent development of the hip joint

Question 2

what happens if it is left untreated?

Answer 2

acetabulum is very shallow
more severe cases: false acetabulum proximal to original one with a shortened limb
severe arthritis due to reduced contact area at any area at any age
gait/ mobility may be severely affected

Question 3

who gets it?

Answer 3

happens in the left hip more than the right
mainly in girls
bilateral in 20% of cases

Question 4

risk factors

Answer 4

Positive family Hx of DDH
Breech presentation
First born babies
Down’s syndrome
Other congenital disorders – talipes, arthrogryposis

Question 5

how does it present?

Answer 5

all hips should be examined clinically shortly after birth
shortening
asymmetric groin/thigh skin creases
click or clunk on the Ortolani or Barlow manoevres
Ortolani test - reducing a dislocated hip by abduction and anterior displacement
Barlow test - dislocatable hip with flexion and posterior displacement

Question 6

how is it investigated?

Answer 6

Positive Ortolani & Barlow test require ultrasound – detects
o Dislocated hip
o Unstable hip
o Shallow acetabulum
XRays can’t be used for the early DDH – femoral head unossified until 4-6 months
XRays are the investigation of choice after 4-6 months
EARLY DIAGNOSIS

Question 7

how is it managed if mild case?

Answer 7

slightly shallow acetabulum and mildly dislocatable but reduced hip
o Close observation = Serial examination & ultrasound

Question 8

how is it managed if dislocated/ persistently unstable hips?

Answer 8

Pavlik harness = Keeps the hip in comfortable flexion and abduction thus maintaining reduction (over-flexing & abducting can result in AVN)
o Full-time for 6 weeks
o Part-time for further 6 weeks once hip is confirmed to be stable
o Can be used to around 4-6 months of age
o Success rate 85-95%

Question 9

how is a persistent dislocation over 18 months managed?

Answer 9

open reduction
o Acetabulum very shallow by this stage
o Clear soft tissues
o May also need osteotomy – shorten & rotate femur
o Pelvic osteotomy – deepen and re-orientate the acetabulum

Question 10

prognosis of persistent/ undiagnosed DDH

Answer 10

tends to have poorer prognosis