Comparative study of role of MRI versus U.S in evaluation and prevention of hip dysplasia

Abstract

Developmental dysplasia of the hip (DDH), formerly known as congenital dislocation of the hip, comprises a spectrum of abnormalities that include abnormal acetabular shape (dysplasia) and malposition of the femoral head, ranging from dislocatable hip and mild subluxation to fixed dislocation. (Dezateux Cet al, 2007).

The origin and pathogenesis of DDH are multifactorial. Abnormal laxity of the ligaments and hip capsule is seen in patients with DDH. The maternal hormone relaxin may also be a factor. Causes of oligohydramnios are thought to be reduced in utero space, movement restriction, and being a first-born child. Extreme hip flexion with kneeextension, as in the breech position, tends to promote femoral head dislocation and leads to the shortening and contracture of the iliopsoas muscle. (DezateuxC et al, 2007).

Delayed diagnosis of mild hip dysplasia isan important cause of secondary osteoarthritisdespite routine screening of infants, accountingfor approximately 25% of all patients requiringtotal hip arthroplasty. The radiographicdiagnosis of hip dysplasia in the young adultmay be subtle. (Beltran LS et al,2013).