2. It is a spectrum of intra-capsular displacement of femoral
head from its normal relationship with acetabulum
before, during or just after birth.
Presents in different form in different ages
The syndrome in newborn consists of instability of hip such
that femoral head can be partially or fully be displaced
from the acetabulum and be reducible on examination.
The term DDH encompasses syndrome ranging from
dysplasia and subluxation to frank dislocation.
3. Dysplasia – Deficient development of acetabulum.
Obliquity and loss of concavity of acetabulum with
intact shenton’s line.
Subluxation – Displacement with some contact remaining
between articular surfaces. Has widened tear-drop- head
distance, centre edge angle <20, break in shenton’s
line.
Dislocation – Complete displacement of joint with no
contact between original articular surfaces.
Teratologic Dislocation – occurs with other disorders like
myelodysplasia, arthrogryposis, etc.
are dislocated at birth,
have limited range of motion,
not reducible
4. Incidence
1.4/1,000 in newborns(40% after 1st week, 10% after 1 month)
10/10,000 born with subluxation or dysplasia
2.3 /100 have clinical finding
8/100 have ultrasound abnormality
Risk Factors
Female : Male – 6:1
First born
Family history (6% one affected child, 12% one affected parent, 36% one
child + one parent)
Oligohydramnios
Breech delivery –in 1in 35 breech deliveries, increased in frank breech
Native Americans - swaddling cultures
Associated Conditions
Torticollis – 15-20%
Metatarsus adductus – 1.5 – 10%
Oligohydramnios
5. Etiology
Etiology is multifactorial and influenced by
genetic, hormonal and ecological influences.
1. Congenital
2. Teratologic Eg. Asso with AMC
3. Syndromic – with larson, Freeman-sheldon
syndrome, diastrophic dysplasia
4. Neuromuscular – asso with spasticity, polio,
meningomyelocele
Inheritence – Autosomal Dominant trait with
incomplete penetrance
6. Predisposing factors
Ligamentous laxity – d/t newborn’s response to maternal relaxin
hormone.
- Increased ratio of collagen III to collagen I.
Prenatal positioning/mechanical forces - in breech delivery
(more in frank breech-risk20%). As left sacro-anterior position
is more common than right, left hip is at higher risk for
dislocation.
- more in first born
- more in oligohydramnios
Post-natal positioning – Waddling
Racial predilection - in blacks and Asians.
in whites and Native Americans
7. Development
Both femoral head and acetabulum develop from the same
piece of mesenchyme of primitive limb bud. A cleft appears to
separate them at 7-8 wks. Hip joint is developed at 11 th wk.
At birth, acetabulum is composed of cartilage with a thim rim
of fibro-cartilage around it(Labrum)
The structure of the acetabulum is determined by the femoral
head which is placed inside it.
Centre for ossification of femoral head appears between 4th
and 7th months of post-natal life and grows until physeal
closure.
Acetabulum fuses at around 18yrs.
Any deviation from normal embryogenesis leads to
malformations. E.g. PFFD
8. Development in DDH
At birth, the affected hip spontaneously slide in and out of the
acetabulum. Postero-superior wall of acetabulum looses it sharp
contour and neolimbus is formed.
This sliding in-and-out produces a ‘clunk’
Some hips spontaneously reduce and undergo normal
development, while others develop secondary changes.
Secondary barriers to reduction develop –
Thickened limbus which then hypertrophies and inverts
presenting as a diaphragm between femoral head and acetabulum
Pulvinar – pad of fatty tissue in depths of acetabulum
Ligamentum teres elongates and thickens
Transverse acetabular ligament hypertrophy
Hour-glass constriction of hip capsule
contracted ilio-psoas cause further capsule narrowing
9. If stable reduction is achieved at early stages (till about 8
yrs), the structures remodel and normal development
ensues.
Changes in hip that remain dislocated – acetabular roof
gradually becomes more oblique, cavity flattens, medial wall
thickens
In adults, presents as high riding dislocation and cases with
fully dislocated hip may remain free from degenerative
changes.
In adults with untreated subluxated hips, instability persists
and degenerative changes appear including subchondral
sclerosis, cyst, osreophyte formation, loss of articular
cartilage.
10.
11.
12.
13. Clinical Features
Gait abnormality - Adductor lurch/ waddling gait
Limb length inequality
Galleazi’s sign
Asymmetric gluteal folds
Increased lumbar lordosis
Scoliosis
Limited Abduction
Telescopy of hip
High placed G.T.
Ortolani’s sign
Barlow’s sign
Klisic’s sign
15. Investigations
X-rays
Ultrasound
CT
MRI
Arthrography – Gold standard
On Xrays- Hilgenreiners line
- Perkins line
- Shenton’s line
- Acetabular Index
- Centre-edge angle of wilberg
- Acetabular depth to width – normally >38%
- Widened acetabular tear-drop
Von-Rosen’s view – with hip abducted internally rotated, and extended
16. In normal hips, medial beak of the femoral metaphysis lies in lower inner quadrant
19. Centre edge angle of Wilberg
19 or more in 6-13 yrs
25 or more in above 14 yrs
20. Ultrasonography
1. Static non-stress technique – Graf
2. Dynamic stress technique – Harcke
3. Dynamic standard minimum examination (DSME)
Graf Technique – Morphologic assessment, relies on anatomic
landmarks
3 lines-
Baseline- line of ilium as it intersects bony and
cartilaginous portions of acetabulum
Inclination line – Line along the margin of cartilaginous
acetabulum
Acetabular roofline – Along the bony roof
Angle between roof and base line – Alpha - >60 ,
evaluates bony acetabulum
Angle between inclination and base line- Beta - <55 ,
evaluates cartilaginous acetabulum
21.
22. Graf Classification
Class Alpha angle Beta angle Description treatment
I >60 <55 Normal -
II 43-60 55-77 Delayed Observe/
ossification harness
III <43 >77 Lateralisation Pawlik harness
IV unmeasurable - Dislocated Pawlik
harness/
closed vs open
reduction
23. Arthrography
GOLD STANDARD
Using Sodium-diatriazoate 76% in 1:1 dilution through
median sub-adductor approach
Findings-
Blunting of rose thorn sign outlining the limbus
Hour-glass constriction of capsule
Medial pooling of dye >7mm
Filling defect in acetabular floor d/t pulvinar
Filling defect in acetabulum d/t hypertrophied ligamentum
teres
24. Management
0-6 months – First watch, if ortolani +ve Pawlik harness in 100-110`
flexion
till 6 to 8 wks before weaning is started
Follow-up weekly using USG
Success- 70-90%
6 – 18 months – closed reduction and immobilization in hip spica. May
require adductor tenotomy before reduction.
Position – Flexion > 90`, abduction 30-40` (within safe zone of Ramsey)
internal rotation – 10-15`
Hyperflexion may cause femoral nerve palsy and inferior dislocation.
Excessive abduction/internal rotation may cause AVN.
Duration – 6 weeks- 6 months
Check after every 6 wks and re-apply cast in case of instability.
Reduction considered stable if abduction can be done till 20` from
max. abduction and extension beyond 90` without redislocation
25. Indication for open reduction –
Failed closed reduction
Persistent subluxation
soft tissue interposition
unstable reduction
18 months – 3 yrs – open reduction, may require osteotomy
Beyond 3 yrs – Open reduction + osteotomy + acetabular
reconstruction