- A spectrum of disorders ranging from complete dislocation of the femoral head to a reduced hip joint with acetabular dysplasia
1. Complete hip dislocation.
2. Partial hip subluxation.
3. Hip dysplasia (incomplete development).
- family history - may reflect laxity of ligaments
- Race- common in white
- Breech presentation - Exaggerated positioning in acute flexion and adduction in utero may occur
- Female sex - the presence of maternal relaxin in the fetal circulatory system
- large fetal size
- First born child
- With the child is lying on a flat surface, flex the hips and knees so the heels rest flat on the table, just distal to the buttock .
- A dislocated hip is signaled by relative shortening of the thigh compared with the normal leg, as shown by the difference in knee height level.
- This test is almost always useless in children under 1 year of age and is negative if dislocation is bilateral.
- This is a provocative test that picks up an unstable but located hip; it is unsuitable for a dislocated hip.
- Thighs are gently grasped in the hand, with the thumb at the lesser trochanter and fingers at the greater trochanter . The hip is adducted slightly and gently pushed posteriorly with the palm.
- Detection of "pistoning," or the sensation of the femoral head subluxating over the posterior rim of the acetabulum, is a positive finding.
- This test detects hips that are already dislocated.
- The flexed limb is grasped as in Barlow's test. The hip is abducted while the femur is gently lifted with the fingers at the greater trochanter.
- In a positive test, there will be a sensation of the hip reducing back into the acetabulum.
- We can diagnose DDH in this period by positive Ortolani’s test or Barlow’s test.
- Asymmetry of the skin fold may help, but its not specific.
- Shortening of the limb at this age doesn’t exist.
- We cant use X-rays because the acetabulum and proximal femur are cartilaginous and wont be shown on X-ray.
- USG is the best method to Dx.
In the early childhood:
- Parents notice asymmetry of creases of groin, limitation of movement of affected hip or click every time hip is moved
In older children:
- Complaints of limping, waddling gait (bilateral DDH), Trendelenburg’s gait (unilateral DDH), lumbar lordosis, limitation of hip abduction, etc…
Von Rosen view:
hips abducted 45º & medially rotated.
We draw a line through the central axis of the femoral shaft.
in normal hip ( ossific nucleus )will be inside the acetabulum.
in dislocated hip it will be above acetabulum.
Delayed development of ossific nucleus / smaller
Horizontal line of Hilgenreiner:
drawn between upper ends of tri-radiate cartilage of the acetabulum.
Vertical line of Perkins:
drawn from the lateral edge of the acetabulum vertical to horizontal line.
Normal hip: the ossification center of the femoral hip lower medial quadrant.
Dislocated hip: upper lateral quadrant.
angle between horizontal line of Hilgenreiner and the line between the two edges of the acetabulum.
normal hip 20º-300
dilocated or dysplastic hip ≥ 30º
semicircle between femoral neck and upper arm of obturator foramen, in dislocated hip this line is broken.
The earlier the better.
Exact treatment depends on patient age at presentation and degree of involvement
Goal is to:
1.Flex and abduct hips.
2.Reduce femoral head and maintaining it.
Reduction can be achieved by closed manipulation , traction followed by closed reduction and opened reduction
maintenance can be done using plaster cast(frog leg or Batchelor) or splint (von Rosen’s splint)
- Acetabular reconstruction procedure
- Salter’s osteotomy
- Chiari’s pelvic displacement osteotomy
- Pemberton’s pericapsular osteotomy
- From (0-6 months)
A dislocated hip at this age may spontaneously reduce over 2-3 weeks if the hip is held in a position of flexion.
Reduction by closed manipulation and maintained with plaster cast or splint
- From 6 months -2 year
Gentle closed reduction of the dislocation under a general anesthetic and maintenance of a located position for 2-3 months in a hip spica cast usually stabilize the joint
- From the age of 2-6 years:
open reduction with osteotomy
- 6-10 years
No treatment for bilateral
Open reduction with reconstruction for unilateral
- After 10 years
Only indication for treatemnt is pain. If only one hip affected total hip replacement may be done.