Developmental Dysplasia of the Hip: Optimal Ultrasound Screening Strategy Among High Risk Newborns

Abstract

Musculoskeletal ultrasonography is becoming an attractive imaging modality for screening of high risk infants for DDH because of its advantages such as accessibility, low cost, rapid examination and ability to detect the soft tissues & cartilage which cannot be seen by conventional radiography. Hip ultrasonography has the ability not only to visualise the unossified parts of the newborn hip but also to show movement of the femoral head within the socket. Ultrsonographic screening of all newborns can identify cases at an earlier age and lead to earlier treatment and prevent complication. So we conclude that the hip ultrasound screening of high risk infants for developmental dysplasia of the hip is important for early diagnosis & treatment. The current study included 270 cases of high risk infants for DDH. Their ages ranged from 4weeks to 6 months. We found that the most prevalent risk factor for hip dislocation in our study was ceaserean section delivery followed by breech presentation and oligohydraminos. The mean value of Alpha angle of the right hip was high than that of the left hip, where mean values of Beta angle of left hip was high than that of right hip. Graf type degree Ia was the most frequent degree in the right & left hips followed by IIa in right hip and IIb in left hip. Caesarean section delivery was the most prevalent risk factor in Graf type degree Ia, IIa & Ib in the right hip and in Graf type degree Ia, IIa & IIb in the left hip. Clinical suspicion was more frequent in Graf type degree IIc. Positive family history & oligohydramnios were the most frequent risk factors in Graf type IIb in the right hip. Graf type Ia was the most frequent degree among both males & females in the studied group in the right and left hips. Among risk factors breech presentation and oligohydramnios were significantly higher in female infants than male infants while caesarean section was significantly higher in male infants than female infants. Normal degree of hip stability is the most frequent degree in the right and left hips by Harche dynamic technique.