This document discusses radiological imaging of pediatric hip conditions. It begins by defining developmental dysplasia of the hip (DDH) as abnormal development of the ball and socket hip joint. Risk factors, clinical features, and imaging findings for DDH are described. Plain radiographs and ultrasound are the main imaging modalities used to evaluate DDH. Hip septic arthritis is also covered, with pathogenesis, clinical presentation, and imaging discussed to differentiate it from transient synovitis. MRI is useful to detect bone marrow signal changes and enhancement patterns that can distinguish between pyogenic and tuberculous septic arthritis.

1. Radiological Imaging
of
Pediatric Hip
Dr Girish G [PG]
Moderator : Dr Madan Mohan [MD radiology]

2. Objectives
Developmental dysplasia of the hip..(DDH)
Transient synovitis vs Septic artrities arthritis

3. Developmental dysplasia of the hip
(DDH)
Definition :
Ball and socket hip joint fails to develop normally,
the socket of the hip joint (acetabulum) is usually shallow
and the ball (femoral head ) can be loose or completely
dislocated

4. Risk Factors
Female
First born children
Family history Oligohydramnios •
Breech
Left more common (left occiput ant),

5. Etiology :
•Multifactorial
•Abnormal laxity of ligaments
and hip capsule
•Maternal hormone relaxin
•Causes of oligohydromnios

6. Clinical features of DDH
Asymmetrical skin fold

7. Apparent shortening of the femur

8. Physical examination

10. Imaging Findings
Plain radiogram : Gold standerd
Ultrasonography : in first 2week
of life [ beast before 4-6m when
femoral head cartilaginous]

11. Plain radiogram
Hilgenreiner line is drawn horizontally
through the superior aspect of both triradiate
cartilages.

12. Perkin line is drawn perpendicular to
Hilgenreiner line, intersecting the lateral most
aspect of the acetabular roof.

13. The upper femoral epiphysis should be
seen in the inferomedial quadrant
( below Hilgenreiner line, and medial to
Perkin line).

14. Acetabular angle is formed by the intersection
between a line drawn tangential to the
acetabular roof and Hilgenreiner line,
A acute angle. It should be approximately 30
degrees at birth and progressively reduce with
the maturation of the joint

15. Shenton line is
drawn along the
inferior border of
the superior pubic
ramus and should
continue laterally
along the
inferomedial
aspect of the
proximal femur as
a smooth line.

18. Radiographic measurement in DDH in adults
Lateral center-edge (CE) angle (or angle of Wiberg)

19. Tönnis angle (or HTE angle or acetabular index)

20. Sharps angle
The Sharps angle gives a global estimation of
acetabular inclination

21. Ultrasonography : in first 2week of life
[ beast before 4-6m when femoral head
cartilaginous]
ultrasound examination be performed in
coronal view
Transverse view
7-5 mhz in < 7month
5 mhz in < 7-12 month

23. Ultrasound linear
transducer is placed
parallel to the lateral
aspect of the infant’s
hip.
CORONAL VIEW

26. Graf α Angle
The Graf α angle is measured in the coronal plane
Defined as the angle formed between the vertical cortex of the
ilium and the acetabular roof.

27. Graf β Angle
The Graf β angle is formed by a line through the vertical
ilium and the cartilaginous acetabular labrum Graf β angle
greater than 55° is abnormal.
With superolateral femoral head displacement, the labrum
is elevated, thereby increasing the β angle

29. Modified Graf Classification Scale

37. Real-time coronal sonogram of the hip with
calculation of the d/D ratio.
Coverage of 58% or greater is considered normal
d-Bony acetabular depth
D-Diameter of the cartilaginous femoral head

38. Method depends on Age
1] Birth to 6 months :
Double napkins , Pavlik harness or hip spica cast
2] 6 months – 12 months : Closed reduction and
hip spica casts
3]12 months – 18 months : Possible closed /
possible open reduction
4]Above 18 months : Open reduction and
Acetabuloplasty
5]Above 2 years : Open reduction, acetabulplasty,
and femoral osteotomy

39. Hip Septic Arthritis – Paediatric
Definition : Purulent infection of the hip joint space
M>F
Causes

41. Pathogenesis: Acute septic arthritis
Bacteria deposits in synovium producing inflammation
↓
Edema and hypertrophy of synovial membrane and joint
effusion
↓
Hyperemia and immobalisation
↓
Destrction of the cartilagenious membarne and reduction in
the joint space
↓
Iflamatoury pannus further destroy the articular cartilage
↓
Massive destrction and separation of bone ends , sublaction
and dislocation
↓
Bone recalcify ---- fibrous/ bony annkylosis

42. A] In the early stage, there is an acute synovitis with a purulent
joint effusion
B] Soon the articular cartilage is attacked by bacterial and
cellular enzyme.
C] If infection is not arrested , the cartilage may be completely
destroyed
D] Sequlae include necrosis, sublaxation, dislocation and
ankylosis

43. Imaging
Plain x ray
1]Early Stage – Normal
Look for soft tissue swelling, loss of tissue planes,
widening of joint space and slight subluxation due to fluid in
joint.
2] Late stage – Narrowing and irregularity of joint space,
erosion of epiphysis or metaphysis , ostiporosis
3]Plain film findings of superimposed osteomyelitis may
develop (periosteal reaction, bone destruction, sequestrum
formation).

44. On right side : a large effusion with displaced fat planes,
early destruction of the right femoral epiphysis with
subluxation. There is irregularity of the metaphysis
(infection crosses growth plate) and also irregularity of the
acetabular roof

45. Interval radiograph after 2 weeks shows more marked destruction of
the right femoral head epiphysis.

46. lateral subluxation of the right upper femur with widened
right medial femur neck to tear drop distance as compared
to the normal left side as seen; differentials may include a
moderate right hip effusion.

47. Radionuleotide scan :
1]Localise the site of infection
2]Positive as early as 2days after onset of symptoms
3]Increased articular activity in blood flow
4] Decreased uptake in the epiphysis as result of
ischemia

48. Ultrasound
1]More reliable in revealing a joint effusion in early cases.
Widening of space between capsule and bone of > 2mm
indicates effusion.
2]Echo-free - transient synovitis
3]Positively echogenic septic arthritis

49. Oblique sagittal ultrasound of the hip of a
17-month-old child with septic arthritis
shows an echogenic effusion and synovitis

52. S. Arttrities
Purulent infection of
the hip joint space
Transient synovities
self-limiting acute
inflammatory condition
affecting the synovial lining of
the hip.
Joint effusion positive USG: echo seen Positive USG : echo free
Synovial membrane
hypertrophy
Positive Positive
Signal abnormality in
adjacent bone marrow on
MRI
Positive Negative
DWI imaging on MRI Restriction Positive No restriction
Colour Doppler USG increased normal
Associated with
ostiomyelities and
adjuscent marrow edema
yes No

53. MRI- both tenosynovities and septic arthritis show
T1 hypo T2 /STIR joint effusion
Contrast enhanced image [T1+C]-
Rim of enhancing hypertrophic synovial membrane
differentiated by hypo intense joint effusion

54. MRI-
1]septic arthritis show signal intensity alteration in the
bone marrow of affected hip joint
2] In transient synovities cases show no such altered
signal entity in bone marrow
T1- poorly defined low signal intesity
T2-/STIR: hyperintese
Contrast study : show enhancment

59. Tubercular septic arthritis – erosions. Pyeogenic – less likely

60. Tubercular septic arthritis – synoviam intermediate
signal with minimal hyperintnse joint effusion
Pyeogenic – distiction bewtween synovium and joint
effusion difficult on non contrast both are hyperintnse

61. Tubercular septic arthritis – boundries
are smooth
Pyeogenic – boundaries irregular with
extra-articular spread

62. Tubercular abscess smooth thin
enhancing rim
Pyeogenic abscess – thick irregular ill-
defined enhancing rim

63. THANK YOU