Role Of Ultrasonography In Diagnosis Of Congential Dislocation Of The Hip:

Khaled Mohammed Abd-ulla

Early diagnosis of developmental dysplasia of the hip in newborns isessential if treatment is to be successful. Screeing of newborns isappropriate because developmental dysplasia of the hip has a highprevalance and significant morbidity and is treatable. Screening by clinicalexamination alone has shortcomings, and the use of sonography forscreening has been proposed (Harcke H. T. 1994). .’Hip sonography enables an accurate and clinically rlevant evaluationof hip maturation during the first days of human life. Experience hasshown that an integration of hip sonography into neonatal screeningprogramms IS useful and necessary because clinical and evenroentgenographic does not always establish a confinned diagnosis ofdysplasia (Schuler et al., 1990).Various sonographic techniques widely spread used. It’s found byHaller J. that the area for ultrasound examination of the pediatric pelvis isbest studied in transverse and longitudinal scans with the patient in supineposition.In ’general, the best compromize between penetration and resolutionIS provided by a 7mm diameter, 5 MHz transducer with a short internalfocus in neonates and small infants (Ha/lerJ.O et al., 1981). Dynamicand static sonography has become the imaging technique of choice in thediagnosis and follow up of developmental dyspalsia of the hip. (Soholeskiet 01., 1993).117In vienna speising Hospital and Benha University Hospital, 600infants ”one week to 10 months” were examined by Hosny,sonographically. Examination and interpretation of the sonographicpictures were performed according to the principles and guidelines ofGraf. Hips classified into 4 major sonographic types:Normal; delayed ossification; subluxation and dislocation.Type I: ex: angle > 60, bone roof contour is good, iliac promontoryaangular or slightly rounded and the cartilage roof is coveringthe head.Type II: ex: angle is 59-43, bony roof contour is satisfactory, iliacpromontory is rounded and cartilage roof is covering the head.Type III: ex: angle is < 43, bony roof contour is poor, iliac promontory isflat and cartilage roof is everted.Type IV: ex: angle is < 43, bony roof contour is poor, iliac promontory isflat and cartilage roof is trapped between the femoral head andthe acetabular cavity. (Hosny, 1994).Ther’s a direct correlation between the sonographic types andtreatment and follow up of cases of hip dysplasia and dislocationAccording to the study of Exner, the policy of treatment recommended isas follows:1- Observe hips with ex: angle < 55° and > 50°. Recommend ”doublediapering” to allow the parents to do something other than waiting;repeat examination after 4-6 weeks.2- For dysplastic hip with no dislocation ec angle S;49°, 13<72°, prescribeabduction brace (modified Frejka’s pillow) worn over the clothes;repeat examination after 2-3 weeks. If no improvement occurs,prescribe Pavlik harness.3- For dysplastic hip with mild dislocation (ex:: :$:49°, 13> 72°, <900),prescribe Pavilk harness; repeat examination after 2 weeks.4- For dislocated hip (13) 90°), prescribe adhesive plaster extension; repeatexamination weekly. (Exner. /988). •Sonographic screerung of all newborns has three principaldrawbacks:1- In a number of infants, sonography shows minor abnormalities of bothstability and acetabular development that will resolve by a later agewithout treatment.2- The observation and treatment of these false - positive cases as well asthe process of screening every newborn, consume considerableresources.3- The final drawback is that the few cases of dysplasia tha.