This document discusses developmental dysplasia of the hip (DDH), including its definition, incidence, causes, clinical tests for diagnosis, imaging techniques, and management approaches. DDH results from abnormal development of the hip joint and can range from instability to complete dislocation. Risk factors include female sex, breech positioning, and family history. Clinical exams include the Ortolani and Barlow tests. Ultrasound and x-rays are used for imaging. Treatment depends on age and severity, and may involve harnessing, casting, or surgery to achieve a concentric reduction without tension. The goal is normal development through positioning the femoral head in the acetabulum.

1. Developmental Dysplasia of the Hip
by
Dr. Mostafa El-Sebai Hammad

2. Definition and terminology
• First CDH, Now DDH
• Klisic 1989: Congenital dislocation of the hip, a bief report):
proposed “Developmental displacement of the hip”
as not all cases are present at birth and that some
cases can develop later-on
• Modern diagnostic imaging allowed more
understanding of the more subtle forms of
Dysplasia, Instability, Subluxation or
So it is now Developmental dysplasia of the hip

3. Incidence
• Neonatal instability 1/100
• 1/1000 develop DDH
• Incidence is 34/1000 when U/S is utilized for diagnosis
• The left hip is the most affected hip
• Girls are affected 5 times more than boys.

4. Aetiology
Polygenic
Hormonal: Estrogen ; relaxin
• Maternal relaxin hormone produce ligamentous
laxity that is necessary for the expansion of the
maternal pelvis,
• cross the placenta and induce laxity in the infant.
This effect is much stronger in female than in male
children.

5. • Post natal positioning
Complete breech 2% Frank breech 20%
Mechanical: breech, swaddle, liquor deficiency
• Intrauterine position

6. The radial growth (width) achieved by the
triradiate cartilage (small blue arrows),
Depth
first 4 years, by the acetabular cartilaginous anlage
(big blue arrows).
After 4 years, increase in acetabular depth occurs
secondary to growth of the acetabular epiphysis at
the labrum.
* thus any excision or radial incisions of the labrum
during the treatment of DDH is ill advised.
Normal growth of the acetabulum

7. Normal growth of the proximal femur
• In the neonate, the entire upper femur is
a cartilaginous structure in the shape of a
femoral head and the greater and lesser
trochanters.
• The growth Depends on Muscle Forces &
Circulation
• 4-6 m ,2ry ossification centers appear
Femoral head , GT at 4y
Why is that relevant

8. Abnormal anatomy

9. Soft tissue Abnormalities
hips that remain dislocated, secondary
barriers develop
-rim of the acetabulum loses its sharp margin and
become flattened and thickened forming a ridge called
by Ortolani “neolimbus” (“clunk“ in Ortolani test)
-The pulvinar thickens
-The ligamentum teres long and thick
-The transverse acetabular ligament is often
hypertrophic as well,
Capsule stretched
-Adductors, quadriceps, as well as Abductors and
hamstring muscles are shortened
-The inferior capsule of the hip assumes an hourglass
shape, eventually presenting an opening that is smaller in
diameter than the femoral head.
-The iliopsoas, which is pulled tight across the isthmus

10. shallow and small acetabulum
flattens MAY eventually becomes convex
Abnormal COVERAGE = ↓ extent of the WB area
of the acetabulum ↓ load-bearing  OA.
Abnormal CONGRUENCY = abnormal fit of the
femoral head to the acetabulum  dislocation
Abnormal Version Excessive antersion
diminished coverage of the femoral head
The acetabulum
Bony abnormalities

11. • Head:  compression against ilium: loss of
perfusion chondrocytes necrosis  deformed ,
Small, Flattened.
• Neck: Short
• Neck shaft angle  coxa valga in most cases due to
excessive adductor pull or inadequate abductor
muscle function
• Anteversion angle  increased .. 35-85º
• The greater trochanteric area is unaffected;
“trochanteric overgrowth” is actually normal
trochanteric growth in the presence of upper
femoral “undergrowth.”
The Proximal femur

12. Form follows Function
Normal development of the head and the acetabulum
depends on the position and the movement of the head inside
the acetabulum through biomechanical molding

13. Clinical Diagnostic Tests
• All newborns should be screened clinically using
Barlow Ortolani
Become less evident as hip laxity resolves and
tightness ensues (4 months), but can be again evident
under anesthesia
You Push the head out

14. Later, diagnosis can be made more reliably through
-limited abduction
<60°
-Galeazzi sign
Both are only of value In unilateral cases
(Galeazzi is +ve with short femur)

15. Other tests
Gluteal fold asymmetry
Klisic sign
Telescopic Sign
If Walker
Trendelenberg (waddling if bilateral)
Increase lumbar lordosis
Pelvic obliquity

16. Imaging
Us : in infant is less than 6 months- no ossific nucleus

17. Graff classification of DDH

18. X-ray
After 6 months
-Delayed ossification at dysplastic side.
-Lateralization, proximal migration
-Broken shenton line
Objective evaluation
 Horizontal line of Hilgenreiner
 Vertical line of perkins
 4 quadrants:
Normal hip: the ossification center of the
femoral hip lower medial quadrant.
Dislocated hip: upper lateral quadrant.
Before 6 months
-von rosen view: (historical for those aged
less than 6 months with no ossific nucleus)
Now replaced by US

20. Better, useful
when epiphysis is
not apparent

21. Acetabular index:
angle between horizontal line of hilgenreiner and
the line between the two edges of the
acetabulum.
27.5 newborn
23.5 at 6 m
20 at 2 years
Center edge angle
mean center-edge angle was 31° (± 7°)

22. Management

23. Screen at birth
Barlow & Ortolani
unstable
Stable
Followup 2 weeks later
Stable
90%
Unstable Examination at
follow-up or with
examination at any age
US assessment
presented before 4 months
α° is decreased (<50)
Β° is increased (>77)
Pavlik harness Age <6 m
Frank dislocation
-Abnormal LL position at birth
confirmed with US
Not reducible
Not DDH
-AMC
-Neuromuscular
Weekly US
Reduced
-full time (23h) for 6 wks
-sleep time 6-8 wks
Not Reduced
-adductor trnotomy
can increase the
safe zon
-not reduced (max 3
weeks)  Stop
Reducible
Human position: at least 90 degrees of
flexion and in the safe zone of abduction

24. Failed Pavlik or
Presented after 6 months
6-12 months
-Adductor tenotomy
-Closed reduction in safe position
(Arthrography if less than 6 m)
-Spica casting in human position
(3 months)
> 1 year (1.5 yrs!)
Success
CT or MRI for follow-up
Failed
Medial approach (Experts only)
-less blood loss -no disturbance of anatomy
-addresses all obstacles,
but can’t do capsulorrhaphy
not suitable for high dislocation
Risk of vacular injury
-Adductor tnotomy
Open reduction through Ant approach
-Capsullorrhaphy
-pelvic osteotomy (Sandiego)
-Femoral osteotomy (derotation,
shortening, V rarely varus)
whatever is needed to achieve
concentric reduction without tension
-Spica cast in slight flexion, 40-60
abduction, minimal to no int rotation

26. -Form follows Function :To achieve normal development, the head must be in the
acetabulum
-Pathological anatomy develop over time.. The earlier the management, the better
the outcome
-if one method of management fail, move to the next
-Reduction must be Tension free
-The best surgery is the first surgery
be a safe surgeon and do no harm
-Eversion of the labrum by
Radial incisions is never indicated
-If you force reduction, IT WILL FAIL
Take home message