Ultrasonography and radiography of the hip in infants

Abstract

Both hip joints in 156 children, aged 2 months to 2 years, were examined by ultrasonography (ultrasound) and radiography. Pathologic findings were based on an increased acetabular index, bony defects of the lateral acetabular rim, and lateral and/or proximal displacement of the proximal femur. Each hip was classified as normal, dysplasia, subluxation, or dislocation. The same diagnosis was reached by ultrasound and radiography in 303 of the 312 hips. The accordance was good in normal joints, in subluxation, and in dislocation. However in 7 of the 15 hips with radiographic dysplasia, ultrasound was normal. These patients were not treated, and spontaneous normalization or improvement occurred in all of them. One parameter only, the distance from the lateral margin of the ossification center of the femoral head to Perkins' line, was measured by both ultrasound and radiography; the correlation was high (r = 0.73). We recommend ultrasound as the primary imaging technique when congenital dislocation is suspected clinically.

Ultrasound measurements in hips of children above 2 years of age:Normal variations in 232 hips

“…Thus, it is essential to establish the limits of normal variation of LHD in the various age groups. The present results showed somewhat smaller values for the upper normal limit of LHD in the two youngest age groups than did our previous study (Terjesen et al 1991). Based on both these studies, the following upper normal limits are suggested: 4 mm at age 2-3 years, 5 mm at 4-7 years, 6 m m at 8-1 1 years, and 7 mm in adolescents above I 1 years of age.…”

“…Although ultrasound (like radiography) entails potential measurement errors due to patient positioning, transducer position, and identification of anatomic landmarks on images, the moderate interobserver variation of f 1 mm (Terjesen et al 1991) confirms our experience that the technique is appropriate in clinical practice.…”

“…limping (6), and out-toeing gait (4). The criteria for including patients in the study were: no previous hip disorder, normal range of motion of both hips, normal anatomic structures of the hip by ultrasound assessment, and ultrasound measurements within the range of normal hips in our previous study (Terjesen et al 1991). Thus, patients with HD, transient synovitis, Perthes' disease, slipped capital femoral epiphysis, and neuromuscular disease were not included.…”

“…We examined all children with ultrasound from the lateral and anterior aspects of the hip joint, according to the method of Terjesen et al (1991). Real-time ultrasound with a 5 MHz linear transducer was used.…”

“…The benefit of ultrasound in evaluating congenital hip dysplasia (HD) in newborns and infants has become well established during the past decade (Graf 1984, Clarke et al 1985, Terjesen et al 1989. In older children, most of the acetabulum cannot be seen because of the large ossification center of the femoral head, but other bony and soft structures of the hip joint are visible, allowing assessment of the extent of femoral head coverage by the acetabulum (Terjesen et al 1991).…”