Ultrasonographic Evaluation of Hip Dysplasia

ULTRASONOGRAPHIC EVALUATION OF HIP DYSPLASIA:
review
L. Breysem, MD
DEPARTMENT OF RADIOLOGY
INTRODUCTION
Clinical hip examination is part of the
first routine examination of every
newborn.
An abnormal clinical examination (positive
Barlow and Ortolani; positive Galleazzi; limited
abduction; asymmetrical skin folds) warrants
further investigation.
INTRODUCTION
Other considerations for further
investigation are :
•Equivocal clinical examination:
examination click or
clunk?
•in case of potential compromise of hip
maturation since development of the hip
joint is a dynamic process
INTRODUCTION
Maturation of the hip can be
compromised: HOW?
– Persisting laxity on clinical examination can have
impact on hip maturation.
– Risk factors at birth:
birth
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Longstanding breech position, twin pregnancy
Positive familial history for hip dysplasia
Postural folding due to lack of amniotic fluid
Foot abnormalities
Macrosome baby
SO FAR, FURTHER INVESTIGATION WHEN…
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Abnormal clinical examination
Equivocal clinical examination
Maturation of the hip could be
compromised
The next LOGICAL step is
imaging
IMAGING OF HIP DYSPLASIA
Why? For DETECTION, FOLLOW-UP and
MONITORING THERAPY
– Ultrasound until 4-5 months of age
– X-ray of the pelvis
– Evaluation of treatment by means
ultrasound, X-ray of the pelvis or CT
of
IMAGING
OF
HIP
DYSPLASIA
Girl, GA: 39we
Breech position
Ortolani +/+
Pavlic since birth
CASE REPORT
6 months old
2 weeks old
2 weeks old
US: severe dysplasia
CT: posterior
dislocation hip L>R
R/ closed reduction
+ cast
8 weeks old
CT: bilateral centered
hip
R/ cast for 3 months,
followed by Pavlic
12 months old
3 years old
R/ Pavlic until 14 months of age
Pelvic X –ray up to 3 years of age:
centered hip, no acetabular dysplasia
IMAGING OF HIP DYSPLASIA
The ultimate goal of this multimodality
and multidisciplinary approach is to lower
the incidence of complications.
In this presentation, we focus on
ULTRASOUND OF HIP DYSPLASIA
ULTRASOUND OF HIP DYSPLASIA
It results in a spectrum of abnormalities
depending on
acetabular morphology,
morphology age,
age evolution in
time,
time stability
normal
immature?
dysplasia
severe dysplasia
As illustrated in next videomontage…
ULTRASOUND OF HIPDYSPLASIA
ULTRASOUND OF HIP DYSPLASIA
However, you need a classification that
can serve as a guideline for appropiate
therapeutic decisions
ULTRASOUND OF HIP DYSPLASIA: classification
(Graf and Rosendahl)
Rosendahl
Normal hip : bony angle of more than 60° (type I Graf) at any age
Immature? : bony angle of more than 50° and less than 3 months of age
(type IIa Graf) Confirm EVOLUTION to maturity with ultrasound !
Dysplasia : bony angle of less than 60° and more than three months of age
(type IIb Graf)
Dysplasia : bony angle of lower than 50° at any age (type IIb, IIc and D
Graf) : centered hip - stable / unstable
Severe dysplasia : bony angle of less than 43° at any age ( IIIa, IIIb and IV
Graf) : decentered hip – unstable
ULTRASOUND: BEST TIMING algorithm
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Normal clinical examination without risk factors: no US
Newborn: normal clinical examination with risk factors (breech,
macrosome baby, postural folding, familial history,..)
– US at 4-6we 1/ stop 2/ US control at +/- 12 weeks; stop 3/ US
monitoring therapy
Newborn: abnormal clinical examination (+ ortolani test, limited abduction,
asymmetrical skin folds,…):
– US in the first week 1/ stop 2/US control at 4-6 weeks; stop or,
if necessary, US control at +/- 12 weeks and stop 2/ US
monitoring therapy
At any age, always appropiate imaging reflecting the clinical findings and
therapy
Monitoring therapy: US until 4-5 months,
months afterwards pelvic X-ray (or
CT)
UP TILL NOW WE HAVE SEEN…
• When further investigation is needed
• Imaging of the hip can be performed with
US, X-ray and CT
• ULTRASOUND of the hip: spectrum of
abnormalities
• Importance of a classification
• Best timing of hip ultrasound
• NOW: ULTRASOUND TECHNIQUE
ULTRASOUND TECHNIQUE
Since the images have to be
reproducible, it’s best to have a
standardized technique available.
Most commonly used are the GRAF
and/or ROSENDAHL technique
ULTRASOUND TECHNIQUE
POSITION OF THE BABY
•quiet and relaxed baby
•Baby on the side, fixed with flexed knees (90°)
•Slightly adduction of the hip by pressing the
knee
ULTRASOUND TECHNIQUE
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(1) RECTANGULAR POSITION of the high resolution linear transducer
(2) SLIDING the transducer from ventral to dorsal to visualize the bony
acetabulum ( * )
(3) ROTATION of the transducer to visualize the straight ilium ( ^ )
NO INCLINATION of the transducer
1
2
3
ULTRASOUND TECHNIQUE: in real time
ULTRASOUND TECHNIQUE: the image
ULTRASOUND TECHNIQUE
NO INCLINATION
of the transducer
because this results in:
-Bowing of the ilium
-Loss of hip anatomy
Next step: ANALYSING THE IMAGE
• STATIC ANALYSIS
• DYNAMIC ANALYSIS
• BIOMETRIC ANALYSIS
STATIC ANALYSIS
ILIUM
^
• visualisation of the three anatomic repairs:
L
*
Labrum acetabulare
Deepest point
of bony
acetabulum
STATIC ANALYSIS
• evaluation of:
– the angulation and edge of the bony
acetabulum: determines the coverage of the
femoral head
– the position of the femoral head-neckgreater trochanter: is the hip centered or
decentered?
– the position of the labrum acetabulare
DYNAMIC ANALYSIS
1/ provocative posterior stress movement on the
knee: unstable? dislocation? (Rosendahl)
Rosendahl
* An example of an unstable hip:
hip the femoral head can
be displaced laterally
DYNAMIC ANALYSIS
* An example of dislocatable hip (displacement to
lateral and posterior):
2we old, spina bifida
Severe dysplasia
Stress: posterior dislocation
of the hip with disappearance of
the femoral head out of the image
Sliding the probe to posterior
to visualize the femoral head
DYNAMIC ANALYSIS
2/ In a dislocated hip: from neutral leg
position to flexed position : is the
dislocation reversible? (Harcke)
Harcke
3/ Consider also acetabular morphology!
(Graf):
Graf instability is important in
association with an abnormal bony
acetabulum
BIOMETRIC ANALYSIS
Angle measurements are usually performed to
confirm the grade of abnormality on the static
image.
By drawing a baseline,
baseline an inclination line and
a roof line,
line you obtain the bony angle (alpha)
and the cartilaginous (beta) angle.
Applying the Graf technique, the bony angle will
primarily classify the grade of abnormality
(confer classification).
BIOMETRIC ANALYSIS
start here
baseline
start here
start here
inclination line
roof line
BIOMETRIC ANALYSIS
start here
start here
roof line
roof line
In this case, the bony edge is
unsharp
In this case,
the bony edge
is sharp
BIOMETRIC ANALYSIS: pitfalls
incorrect!
incorrect!
correct
incorrect!
BIOMETRIC ANALYSIS
Calculation of the
bony and
cartilaginous angle
Cartilaginous angle
Bony angle
BIOMETRIC ANALYSIS
Automatic calculation of femoral head coverage (Morin):
Ratio d/D x 100 (confer d:D on the image): the lower the ratio,
the less coverage
TREATMENT: WHEN?
• Multidisciplinary approach
• Early treatment (< 7- 8 weeks of age): best results
• Confer spectrum of abnormalities and consider:
– centered – decentered?
– In a decentered hip: aspect of cartilaginous
acetabulum
– Evolution of an apparently immature hip
– Age
TO CONCLUDE…
CASE REPORTS
NORMAL
GA: 40 we; boy
Familial history
Ortolani: US at 5 weeks
old is normal
R/ stop
IMMATURE?
GA: 40we;girl
Galleazzi +
US at 6we:
Alpha angle: 58°
R/conservative
Follow-up US
at 12we (not
shown) =
normal
R/ stop
IMMATURE?
GA: 38we; girl
Breech
Ortolani +
US at 6we: bilateral
alpha angle of +/- 50°
R/conservative
Follow-up US at 10 we:
Right hip: alpha of 63°
Left hip: alpha of 54°
R/ Conservative
*good evolution on the
right side
* US follow-up at 4-5mo
for the left hip is still
justified
DYSPLASIA
GA: 39we; boy
Breech
Ortolani/Barlow : - ; Galleazi: +
Asymmetrical skin folds, no limited abduction
US at 3we
6 months
R/ Pavlic for three months
Normal acetabular cover at 6mo at pelvic X-ray
R/ Stop
SEVERE DYSPLASIA
GA: 37we; girl
Arthrogryposis
Limited abduction (45°)
US at 1mo: dislocated hip with
infolding of the labrum acetabulare and
echogenic acetabular hyaline cartilage
4 months
4 years
R/open reduction with pelvic
osteotomy at 1 year of age
Consult at 4 years: symmetrical
abduction / rotation: good result!
CONCLUSION REMARKS
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Education and Expercience !
Use a reproducible standard technique
Classification of the ultrasonographic findings is
necessary for therapeutic decisions
• A suspected immaturity (type IIa Graf) needs to be
confirmed around 12 weeks
• Respect the timing for clinical evaluation, imaging
and therapy
• Early treatment (< 7- 8 weeks of age): best results!
LITERATURE
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Hip Sonography, Second Edition R. Graf Springer, 2006
Developmental dysplasia of the hip, Sewell MD, Rosendahl K, Eastwood DM.
BMJ. 2009 Nov 24;339:b4454
Developmental dysplasia of the hip:background and the utility of ultrasound, Delaney L, Karmazyn B.
Semin Ultrasound CT MRI 32:151-156; 2011
Immediate treatment versus sonographic Surveillance for mild hip dysplasia in newborns, Rosendahl, et all
Pediatrics 2010; 125(1);e9-16
Increased diagnostic information and understanding disease: uncertainty in the diagnosis of developmental
hip dysplasia, A.Roposch, J.Wright Radiology.2007 Feb;242(2):355-9
Ultrasound in the diagnosis of developmental dysplasia of the hip in newborns. The European approach. A
review of methods, accuracy and clinical validity Eur Radiol (2007) 17:1960-1967
Determining the reliability of the Graf Classification for hip dysplasia Clin Orthop Relat Res.2006
Jun;447:119-24
Management of neonatal hip instability and dysplasia Paton Early Human Development (2005) 81,807-813
Developmental dysplasia of the hip. A population-based comparison of ultrasound and clinical findings.
Rosendahl K, Markestad T Acta Paediatr 1996;85:64-9
Thank you for your attention.