Secondary pathological changes in infant with developmental dysplasia of the hip: the application value of high frequency ultrasound

Abstract

Objective To investigate the clinical value of high frequency ultrasound in discovering secondary pathological changes in infant with developmental dysplasia of the hip (DDH). Methods Thirty-four infants with 36 dislocation hips were involved. Among them, 32 were with unilateral dislocation of hip joint, 2 were with bilateral dislocation of hip joint. High frequency ultrasound were used to observe the morphological changes of hip glenoid labrum, adipose hyperplasia in acetabulum, thickness variation of articular capsule, and development of the ossification center of the femoral head. Besides, the morphological changes of hip glenoid labrum and adipose hyperplasia in acetabul were compared with those from MRI. Results The sensitivity and specificity of ultrasound in diagnosing glenoid labral introversion were 82% and 100% respectively. The coincidence rate of diagnosing glenoid labral introversion and glenoid labral extroversion were both 83%. Adipose hyperplasias in acetabul were clearly seen in 31 hips using ultrasound. The thickness of articular capsule in the affected hip and in the healthy hip was (2.8±0.6)mm versus (1.7±0.4)mm, and the difference was obviously significant (P<0.01). The ossification center of the femoral head in the 34 infants were classified as the following four types: ①which was smaller in the affected side than in the healthy side (22/34); ②which was shown in the healthy side (7/34) but not in the affected side; ③which in both sides were not shown(4/34); ④which in both sides were small(1/34). Conclusions Ultrasound is a method of simple, rapid, non-invasive in diagnosing DDH, and it can be used to discover secondary pathological changes in infant with DDH, which provide important reference for clinical diagnosis and treatment. Key words: Ultrasonography; Hip dislocation; Infants; Pathological changes