2. What is Developmental Dysplasia of Hip?
• In DDH, there is delayed ossification of the femoral head
and an abnormally shallow acetabulum.
• predisposing to subluxation and/or dislocation.
• Additionally, late complications, such as osteoarthritis and
avascular necrosis, can occur.
• Dr Rabia Nazir Ch
3. Risk Factors
Female gender
First born
Breech presentation (typically fooling breech)
Family history
Oligohydramnions
Caesarean section
Prematurity
Dr Rabia Nazir Ch
7. DEVELOPMENTAL DYSPLASIA OF HIP
EVALUATION
Evaluated with a standard multimodality imaging algorithm,
depending on patient age.
1. ULTRASOUND : Significant in neonates uptill 5 months
2. RADIOGRAPHY : Once ossification of capital femoral epiphysis (3-6 months)
begins to obscure visualization of sonographic landmarks.
3. COMPUTERIZED TOMOGRAPHY and MRI : CT is reserved primarily
for problem solving, typically in the postoperative period. It is currently used
infrequently because of the disadvantage of ionizing radiation. MRI is being
increasingly used because of its ability to delineate soft tissues as well
osseous structures.
Dr Rabia Nazir Ch
8. ULTRASOUND
• The American College of Radiology recommends
• Standard ultrasound examination be performed in two orthogonal planes:
• a coronal view in the standard plane at rest
• transverse view of the flexed hip with and without stress .
• Three anatomic landmarks—ilial line, triradiate cartilage, and labrum—are used
to measure the α and β angles. A standard plane includes a straight iliac line, the
femoral head with maximum diameter, the tip of the echogenic acetabular
labrum, and the triradiate cartilage. Meticulous scrutiny of the α angle
measurement is necessary because false-positive findings can occur if the
imaging plane is suboptimal. When reporting the α angle, the largest angle, not
the average angle, should be given.
Dr Rabia Nazir Ch
30. Color Doppler
• Color Doppler imaging has been
used to evaluate perfusion to the
proximal femoral epiphysis ,
although there is little literature in
the setting of DDH. After placement
of the Pavlik harness, serial follow-
up hip ultrasound examinations are
performed to assess response to
treatment. The infant is left in the
Pavlik harness and only static
images are obtained
Dr Rabia Nazir Ch
35. Normal values in
children
• newborns - 27.5°
average but should
be less than 28°
• 6 months- 23.5°
• 2 years – 20°
• 30° is the normal
upper limit
Normal values in
adults
33°-38°
Dr Rabia Nazir Ch
36. Shenton's Line
• Shenton line, which
is a C-shaped line
drawn along the
inferior border of
the superior pubic
ramus and the
inferomedial border
of the femoral neck.
A normal Shenton
line should form a
smooth arc
Dr Rabia Nazir Ch
40. ARTHROGRAPHY
Arthrography is typically performed
intraoperatively by the orthopedic surgeon
at the time of reduction. Obstacles to
successful reduction, such as limbus
eversion, can be identified
Dr Rabia Nazir Ch
41. COMPUTERIZED TOMOGRAPHY
• CT is generally reserved for problem solving in difficult cases and
involves a low-dose technique, often in the setting of pre or
postoperative evaluation.
• A recent study compared the use of CT versus MRI to evaluate hip
reduction in patients with DDH and found that both modalities offer
excellent sensitivity and specificity [27]. CT had sensitivity of 100%
and specificity of 96% for the postoperative nonsubluxed hip,
whereas MRI showed sensitivity of 100% and a specificity of 100%.
Dr Rabia Nazir Ch
43. MRI
MRI, like CT, is often reserved for
more difficult cases; however, the
major advantage of MRI is the
ability to delineate soft-tissue
structures as well as osseous
structures without ionizing radiation.
Many MRI studies are ordered in
the postoperative period, usually
after reduction and spica cast
placement. In fact, spica cast
placement is one of the most
common indications for MRI in the
setting of DDH.
Dr Rabia Nazir Ch
48. EPITOME
• Ddh is a disease commonly encountered by pediatric and general radiologists.
• ULTRASOUND : is mainstay modality in children under 6 months.
• Alpha and beta Angles
• RADIOGRAPHY : in children above 5 to 6 months
• Hilgenreiner’s line
• Perkin‘s line
• Shenton’s line
• Acetabular index
• COMPUTERIZED TOMOGRAPHY : limited use preferably postoperative follow-ups
• MRI : increasinglyused for problem solving, and familiarity with the MRI findings of
DDH is important.
Dr Rabia Nazir Ch
