Ultrasound neonatal screening: the effect of anamnestic risk factors on hip dysplasia

Abstract

Hereditary, pelvic respectively breech presentation or abdominal delivery, premature as well as post-term birth and twin pregnancy are considered to be anamnestic risk factors for congenital dysplasia of the hip. The results of ultrasound hip screening of two University hospitals are presented with special regard to the correlation of these risk factors and the occurrence of pathologic hips. 24 different physicians of the orthopaedic departments examined the hips of 6617 newborns (female: 3253--49.2%; male: 3364--50.8%) by ultrasound (screening). 94.6% of the examinations were performed within a period of 5 days after birth. The ultrasound examinations, the assessment of the echograms and classification into types of hip were performed according to Graf's technique. All investigations were assessed retrospectively over the period of time with the help of documentation forms (data of newborn baby, case history, clinical and sonographical findings, kind of therapy and procedure) and statistically checked (Chi-Quadrate-test). In 436 children (6.6%) we found hips required therapy respectively control investigations (type IIa, a < 55 degrees or worse; Graf's classification). For the entire group we achieved the following types of hips (right/left side): Ia--724 (10.9%)/645 (9.8%); Ib--3931 (59.4%)/3892 (58.8%); IIa (> or = 55 degrees)--1733 (26.2%)/1768 (26.7%); IIa (< 55 degrees)--143 (2.2%)/181 (2.7%); IIc--55 (0.8%)/77 (1.2%); D--20 (0.3%)/39 (0.6%); IIIa--9 (0.1%)/11 (0.2%); IIIb--1 (< 0.1%)/3 (0.1%); IV--1 (< 0.1%)/1 (< 0.1%). In newborn babies with cases of hip dysplasia in their family (heredity) and pelvic respectively breech presentation at birth, as well as for girls and the left side we found a significant higher rate (p < 0.05) of hips required therapy respectively control investigations (type IIa, alpha < 55 degrees or worse; Graf's classification). A correlation of the other mentioned risk factors premature respectively post-term birth, twin pregnancy and cases of abdominal delivery without breech presentation was not evident.