ULTRASONOGRAPHIC EVALUATION OF HIP DYSPLASIA: review. L. Breysem, MD DEPARTMENT OF RADIOLOGY

Transcription

1 ULTRASONOGRAPHIC EVALUATION OF HIP DYSPLASIA: review L. Breysem, MD DEPARTMENT OF RADIOLOGY

2 INTRODUCTION Clinical hip examination is part of the first routine examination of every newborn. An abnormal clinical examination abnormal clinical examination (positive Barlow and Ortolani; positive Galleazzi; limited abduction; asymmetrical skin folds) warrants further investigation.

3 INTRODUCTION Other considerations for further investigation are : Equivocal clinical examination: click or clunk? in case of potential compromise of hip maturation since development of the hip joint is a dynamic process

4 INTRODUCTION Maturation of the hip can be compromised: HOW? Persisting laxity on clinical examination can have impact on hip maturation. Risk factors at birth: Longstanding breech position, twin pregnancy Positive familial history for hip dysplasia Postural folding due to lack of amniotic fluid Foot abnormalities Macrosome baby

5 SO FAR, FURTHER INVESTIGATION WHEN Abnormal clinical examination Equivocal clinical examination Maturation of the hip could be compromised The next LOGICAL step is imaging

6 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 of ultrasound, X-ray of the pelvis or CT

7 IMAGING OF HIP DYSPLASIA Girl, GA: 39we Breech position Ortolani +/+ Pavlic since birth CASE REPORT 6 months old 2 weeks old 8 weeks old 12 months old 3 years old 2 weeks old US: severe dysplasia CT: posterior dislocation hip L>R R/ closed reduction + cast CT: bilateral centered hip R/ cast for 3 months, followed by Pavlic R/ Pavlic until 14 months of age Pelvic X ray up to 3 years of age: centered hip, no acetabular dysplasia

8 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

9 ULTRASOUND OF HIP DYSPLASIA It results in a spectrum of abnormalities depending on acetabular morphology, age, evolution in time, stability normal immature? dysplasia severe dysplasia As illustrated in next videomontage

10 ULTRASOUND OF HIPDYSPLASIA

11 ULTRASOUND OF HIP DYSPLASIA However, you need a classification that can serve as a guideline for appropiate therapeutic decisions

12 ULTRASOUND OF HIP DYSPLASIA: classification (Graf and 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 Severe dysplasia : bony angle of less than 43 at any age ( IIIa, IIIb and IV Graf) : decentered hip unstable

13 ULTRASOUND: BEST TIMING algorithm 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 4 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 months, afterwards pelvic X-ray (or CT)

14 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

15 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

16 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

17 ULTRASOUND TECHNIQUE (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

18 ULTRASOUND TECHNIQUE: in real time

19 ULTRASOUND TECHNIQUE: the image

20 ULTRASOUND TECHNIQUE NO INCLINATION of the transducer because this results in: -Bowing of the ilium -Loss of hip anatomy

21 Next step: ANALYSING THE IMAGE STATIC ANALYSIS DYNAMIC ANALYSIS BIOMETRIC ANALYSIS

22 STATIC ANALYSIS visualisation of the three anatomic repairs: ILIUM ^ L Labrum acetabulare * Deepest point of bony acetabulum

23 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

24 DYNAMIC ANALYSIS 1/ provocative posterior stress movement on the knee: unstable? dislocation? (Rosendahl) * An example of an unstable hip unstable hip: the femoral head can be displaced laterally

25 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

26 DYNAMIC ANALYSIS 2/ In a dislocated hip: from neutral leg position to flexed position : is the dislocation reversible? (Harcke) 3/ Consider also acetabular morphology! (Graf): instability is important in association with an abnormal bony acetabulum

27 BIOMETRIC ANALYSIS Angle measurements are usually performed to confirm the grade of abnormality on the static image. By drawing a baseline, an inclination line and a roof 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).

28 BIOMETRIC ANALYSIS start here baseline start here inclination line start here roof line

29 BIOMETRIC ANALYSIS start here roof line start here roof line In this case, the bony edge is unsharp In this case, the bony edge is sharp

30 BIOMETRIC ANALYSIS: pitfalls incorrect! incorrect! incorrect! correct

31 BIOMETRIC ANALYSIS Calculation of the bony and cartilaginous angle Cartilaginous angle Bony angle

32 BIOMETRIC ANALYSIS Automatic calculation of femoral head coverage (Morin( Morin): Ratio d/d x 100 (confer d:d on the image): the lower the ratio, the less coverage

33 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

34 TO CONCLUDE CASE REPORTS

35 NORMAL GA: 40 we; boy Familial history Ortolani: - US at 5 weeks old is normal R/ stop

36 IMMATURE? GA: 40we;girl Galleazzi + US at 6we: Alpha angle: 58 R/conservative Follow-up US at 12we (not shown) = normal R/ stop

37 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

38 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

39 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!

40 CONCLUSION REMARKS 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!

41 LITERATURE Hip Sonography, Second Edition R. Graf Springer, 2006 Developmental dysplasia of the hip, Sewell MD, Rosendahl K, Eastwood DM. BMJ Nov 24;339:b4454 Developmental dysplasia of the hip:background and the utility of ultrasound, Delaney L, Karmazyn B. Semin Ultrasound CT MRI 32: ; 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: Determining the reliability of the Graf Classification for hip dysplasia Clin Orthop Relat Res.2006 Jun;447: Management of neonatal hip instability and dysplasia Paton Early Human Development (2005) 81, Developmental dysplasia of the hip. A population-based comparison of ultrasound and clinical findings. Rosendahl K, Markestad T Acta Paediatr 1996;85:64-9

42 Thank you for your attention.