This document provides an overview of developmental hip dysplasia (DDH), including its definition, risk factors, clinical exam techniques, ultrasound techniques and measurements, and case examples. Key points include: - DDH is underdevelopment of the acetabular component of the hip joint, ranging from a shallow acetabulum to complete dislocation. - Ultrasound is useful for evaluation up to 6 months of age, using coronal, transverse, and stress views to assess coverage, subluxation, and stability. - Measurements like the alpha and beta angles and bony coverage index indicate dysplasia if outside normal ranges. - Early diagnosis and treatment with techniques like the Pavlik harness can

1. Developmental hip dysplasia
Dr.Mohamed Soliman,MSC
• Normal Anatomy
• Definition
• Risk factors
• Clinical exam
• Ultrasound technique
• Hip joint biometry
• cases discussion

2. • Hip joint is Ball and socket joint with wide
range of motion 2nd only to glenohumeral
joint
• 2/3 of sphere
• Covered by articular cartilage
• Cartilage thickest superiorly
• Cartilage thins at head/neck junction
• Ossification centre of femoral head appears
on ultrasound before it appears
radiographically (6th-8th week)
Femoral Head

3. Triradiate cartilage
(growth cartilage)
• formed by portions of ilium, ischium,
and pubis
• unite at triradiate cartilage (growth
cartilage)
• Oriented anterior, inferior, lateral
• Covers > 50% femoral head
• Anterior and posterior rims: Osseous
margins of acetabulum
• Medial wall: Quadrilateral plate ilium
• Echogenic fibrocartilage at edge of
cartilaginous roof is the true acetabular
labrum
Acetabulum

4. • Laxity of joint capsule
• Inadequate contact between
acetabulum and femoral head
• Acetabulum is particularly susceptible
to remodeling during first 10 postnatal
weeks
• Contact between femoral head and
acetabulum is necessary for normal
acetabular development

6. Definition
Developmental dysplasia of hip (DDH) & Congenital dysplasia of hip (CDH)
Underdevelopment of acetabular component of hip joint
Shallow acetabulum
± subluxation of femoral head
± Secondary hypoplasia of femoral head
Ranges from shallow acetabulum to complete dislocation with false acetabulum
Dysplasia: 0.8% newborn (0.3% boys, 1.4% girls)

7. • M:F = 1:4
• female hormone relaxin, which may contribute to ↑ ligamentous laxity
• Left hip is 3x more commonly affected than right hip : Possibly related
to left occiput anterior position of most non breech babies in utero , In this
position, left hip lies against maternal spine, which may limit abduction
Risk factors
1. First child
2. Female
3. Positive family history
4. breech presentation
5. Oligohydramnios
6. Torticollis
7. foot deformity
3% of births are breech
8% of girls with breech birth have developmental hip dysplasia
Due of hip flexed, knee extended position of breech babies in utero

8. Ortolani maneuver
▪ Hip is flexed to 90° and gently abducted while thigh is lifted anteriorly
▪ "Clunk" is felt as dislocated femoral head reduces

9. Barlow maneuver
▪ Hip is flexed to 90° and gently adducted while thigh is pushed posteriorly
▪ "Clunk" is felt as femoral head dislocates

10. • Most useful between birth and 6 months
• Both static and dynamic evaluation
Longitudinal
coronal
Transverse
Static Dynamic

11. Longitudinal coronal plane
Transverse plane

12. Longitudinal Coronal view ("egg in spoon" view)

13. • Most important .
• lateral decubitus position
• the hip flexed to only 20° .
• transducer 10-15° obliquely
(posteriorly) from coronal plane to
obtain straight iliac line
• Position too anterior → false-positive
result
• Gas can be found within normal hip
Longitudinal Coronal view
"egg in spoon" view
Non stress scan

14. single image showing
8
structures
1. straight iliac contour
2. acetabular labrum
3. Osseous acetabular roof
4. cartilaginous acetabular roof
5. triradiate cartilage
6. Ischium
7. center of femoral head
8. Ossified femoral metaphysis
Coronal view
"egg in spoon" view
Non stress scan

15. straight iliac contour
cartilaginous acetabular roof
triradiate cartilage
Ischium
femoral head
Ossified
femoral
metaphysis
Egg in spoon view

16. Osseous
acetabular roof
cartilaginous
acetabular roof
acetabular labrum
Triradiate
cartilage
Ischium
Normal Longitudinal coronal , non stress test
Ossified femoral
metaphysis
femoral head
Ilium

17. • lateral decubitus position.
• transducer in coronal position.
• Barlow maneuver (i.e. posterior
force on adducted and flexed hip)
• Attempt to displace femoral head
from acetabulum during real-time
imaging
• Lack of infant relaxation could
hinder or prevent acquisition of
optimal stress view and can
produce false-negative examination
• Nonstress views provide more
information than stress views
Coronal view
"egg in spoon" view
stress scan

18. Stress test produces an axial section of the femoral head. The femoral head
should appear round in this section.
Normal Longitudinal coronal , stress test

19. Transverse view
golf ball on tee
Ice cream cone

20. • Shows femoral head overlying
triradiate cartilage
• Useful to continue screening hip
during active movement if child
is restless
• Will give indication as to stability
of hip during normal movement
Transverse view
golf ball on tee
Non stress scan

21. single image showing
7
structures
1. Acetabular roof
2. acetabular labrum
3. Triradiate cartilage
4. Femoral head
5. Femoral metaphysis
6. Gluteal muscles
7. Ischium
Transverse view
golf ball on tee
Ice cream cone
Non stress scan

22. Femoral head
Acetabular roof
acetabular labrum
Gluteal muscles
Femoral
metaphysis
Triradiate
cartilage
ischium
golf ball on tee
ice cream cone

23. Normal transverse
Femoral head
Acetabular roof
acetabular labrum
Gluteal muscles
Femoral
metaphysis
Triradiate
cartilage
ischium
ice cream cone

24. golf ball on tee

25. Hip joint Biometry
Ultrasound X ray
1. Graf staging
2. Bony coverage index

26. Acetabular roof line
• Line along osseous
acetabular roof line
• α angle is measured at
intersection between iliac
line and line along osseous
acetabular roof
• α angle is acetabular angle
Reflects
1. steepness of acetabular roof
2. Portion of femoral head
contained within bony
acetabulum
3. Acetabular bony coverage
4. Center of femoral head relative
to iliac straight line
Iliac line
Line along straight
contour of ilium
Labrum line
• Line from promontory to tip of
labrum
• β angle is measured at
intersection between iliac line
and line from acetabular
promontory to tip of Labrum
• Reflects elevation of
acetabular labrum
Ultrasound 3 lines

27. straight iliac contour
triradiate cartilage
Ischium
femoral head Ossified
femoral
metaphysis
Hip joint Biometry
iliac line
α
β

28. β angle
a angle

29. Normal values
α angle > 60°
β angle < 55° .
α angle is more critical than β angle
Measurements outside of these ranges are suggestive of developmental hip dysplasia.

30. Coronal scan shows the hip of a 4-month-old child with the hip in extension. The center of
the femoral head has begun to ossify, showing up as an echogenic focus with posterior
acoustic shadowing.

31. Acetabulum immaturity
Immature
roundish acetabular promontory
mature
Angular acetabular promontory

32. Modified Graf staging
grade a angle Β angle Hip status
Type Ia > 60° < 55° mature hip, angular bony promontory
Type Ib > 60° < 55° mature hip, roundish bony promontory
Type IIa 50-60° 55-77° physiologic immaturity < 3 months
Type IIb 50-60° 55-77° Delayed maturity > 3 months
Type IIc 43-49° >77° critical hip, subluxation, severe dysplasia
Type III α < 43° dislocated hip
Type IV < 43° dislocated hip, inverted labrum

33. Pathological cases

34. • Shallow acetabulum .
• The α angle is 44°
• Moderate femoral head
subluxation.
• The acetabular labrum is
everted.
• The femoral head is relatively
small.
Moderately dysplastic hip
type IIc

35. • The α angle is 25 °
• dislocated femoral head .
• The labrum is interposed
between the bony acetabulum
and the femoral head.
severely hypoplastic acetabulum
type IV DDH.

36. • rounded shallow acetabulum .
• femoral head is severely
subluxed
• the acetabular labrum is
located between the
acetabulum and the femoral
head.
severely dysplastic hip
Type III DDH.

37. • reduction in α angle (34°)
• increase in β angle (55°)
type III DDH.
same patient
measurements

38. • lateral and cephalad displacement
of the femoral head.
• The labrum is interposed between
the femoral head and acetabulum
and is thickened.
• The pulvinar is also thickened.
severely dysplastic hip
type IV DDH.

39. • severe dysplastic acetabulum
with a dislocated hip.
• The bony acetabulum is not
measurable,
• the labrum cannot be well
delineated.
Type IV DDH.

40. * Should have > 50% of femoral head covered by bony acetabulum
* Important and easy to comprehend measurement
bony coverage index

41. straight iliac contour
triradiate cartilage
Ischium
femoral
head
Ossified
femoral
metaphysis
Hip joint Biometry
Bony coverage index
iliac line
d
D

42. Longitudinal coronal ultrasound
normal hip with
a well-covered
femoral head
The portion of the
femoral head
diameter (D) covered
by bone acetabulum
(d) is > 50%
(D/d > 50%).
Iliac line

43. Important terminology according to bony coverage index
Capsular laxity
 50% bony coverage femoral head at rest
 < 50% bone coverage on stress examination or active movement
Subluxation
< 50% bony coverage at rest
o Some centers define subluxation as < 33% bony coverage and 33-50% as
indeterminate
Dislocation
Femoral head lies completely outside of bony acetabulum at rest

44. • Immature acetabulum with a
roundish acetabular promontory
• good bony coverage of the
femoral head.

45. Previously roundish bony
acetabular promontory has now
become less rounded .
It is expected finding with normal
maturation of the acetabulum.
Normal acetabular labrum .
same patient
Follow up 2 months later

46. roundish acetabular promontory
indicative of acetabular immaturity.
The acetabular roof is still deep with
good bony coverage of the femoral
head.
Longitudinal coronal ultrasound

47. slightly roundish acetabular
promontory . However, the
acetabular bony roof is well
formed and deep.
same patient
contralateral hip

48. • moderate capsular laxity
• < 50% coverage of the femoral
head by the bony acetabulum as
indicated by the iliac line
• Treatment is indicated
• with follow-up ultrasound in 4
weeks.
Same patient
during stress scan

49. • femoral head is now not subluxed
during stress maneuver,
• index > 50%.
• The acetabulum promontory is
sharper.
Early diagnosis and proper treatment
can lead to dramatic improvement.
Same patient
Stress scan
4 weeks later

50. • immature acetabulum
• roundish acetabular
promontory .
• The majority of the unossified
femoral head lies below the
iliac line .
• good bony coverage.
Longitudinal ultrasound

51. • Most of the femoral head lies
above the iliac line , indicating
capsular laxity and is common
in newborns and premature
infants.
• Gas in the hip joint (normal finding)
Same patient during stress test

52. Radiographic findings ( after 6 months)
Hip dysplasia associated with
• relatively shallow acetabulum
• slanting roof
• relatively small superolaterally placed femoral head
Acetabular index
Perkin line
Hilgenreiner line
HPA

53. Hilgenreiner line
Perkin line
Perkin line
Acetabular index
Hilgenreiner line
• links tops of both triradiate
cartilages
• Femoral metaphysis lie below it
Perkin line
• perpendicular to Hilgenreiner line
through lateral margin of bony
acetabulum
• Femoral capital epiphysis should
lie within inner lower quadrant of
intersection between Perkin and
Hilgenreiner lines
Acetabular index
• angle between acetabular roof
and Hilgenreiner line
• 30-32° in newborn; ↓ in older
children

54. left-sided acetabular dysplasia
• dislocation of the femoral head
• delayed ossification of the left
femoral capital epiphysis.
Hilgenreiner line
Perkins Perkins
Acetabular
index
angle

55. 1. Ultrasound is useful up to 6 months of age
2. Limited at 6-9 months and not useful thereafter
3. Ensure that definitions of capsular laxity, subluxation, and dislocation are
clear to those interpreting the ultrasound result
4. Useful to have these definitions written on ultrasound report
5. On ultrasound examination, incorrect orientation can make deep hip appear
shallow , Not possible to make shallow hip appear deep
6. Prognosis is excellent if dysplasia is diagnosed and treated early, even for
severe degree of DDH
7. Key to diagnosis rests on obtaining correct coronal (longitudinal) view
8. If in doubt, repeat ultrasound in 2-4 weeks

56. Prognosis
• Physiological hip joint laxity of newborn without acetabular dysplasia resolves
spontaneously
• Early treatment of DDH: Excellent result with harness or splint
• Delayed treatment of DDH: Irreversible dysplasia
1. Limited range of movement, adductor spasm
2. Limb shortening, osteoarthrosis
Treatment
•Conservative
o Pavlik harness ± closed reduction (if dislocated)
•Surgical for dislocation or subluxation failing to respond to conservative
treatment
1. Open reduction + spica cast
2. Adductor tenotomy + release of iliopsoas
3. Varus (derotational) vs. reconstructive osteotomy

57. Clinical photograph shows a baby
wearing a Pavlik harness to treat
DDH.
The harness helps to keep the hips
in an abducted flexed position.
This position ensures that the
femoral heads remain within the
acetabular fossae.