Porth's Essentials of Pathophysiology, 4e

Disorders of the Skeletal System: Trauma, Infections, Neoplasms, and Childhood Disorders 1103

C h a p t e r 4 3

Ortolani Test

of DDH. Thus, the hips of children presenting with con- genital abnormalities should be examined carefully. Early diagnosis of DDH is important because treat- ment is easiest and most effective if begun during the first 6months of life. Also, repeated dislocations cause damage to the femoral head and the acetabulum. In infants, signs of DDH include asymmetry of the hip or gluteal folds, shortening of the thigh so that one knee (on the affected side) is higher than the other knee, and limited abduction of the affected hip 63–67 (Fig. 43-20). The asymmetry of gluteal folds is not definitive but indicates the need for further evaluation. Physical examination remains the key to the diagnosis of DDH. However, the U.S. Preventive Services Task Force (USPSTF) recently concluded that evidence was insufficient to recommend routine screen- ing of asymptomatic infants as a means of preventing adverse outcomes. 66 This recommendation applies only to infants who do not have obvious hip dislocation or other abnormalities evident without screening. Several examination techniques can be used to screen for a dislocatable hip. Two provocative dynamic tests for assessing hip stability in the newborn are the Ortolani maneuver (for reducible dislocation) and the Barlow maneuver (for the dislocatable hip) 8,63–65 (Fig. 43-21). The Galeazzi test is a measurement of the length of the femurs that is done by comparing the height at the knees while they are flexed at 90 degrees. An inequal- ity in the height of the knees is a positive Galeazzi sign and is usually caused by hip dislocation or congenital femoral shortening. This test is not useful in detecting bilateral DDH because both leg lengths will be equal. In an older child, instability of the hip may produce a delay in standing or walking and eventually cause a character- istic waddling gait. When the thumbs are placed over the anterior iliac crest and the hands are placed over the lateral pelvis in examination, the levels of the thumbs are not even; the child is unable to elevate the opposite side of the pelvis (positive Trendelenburg test). Diagnosis of DDH is confirmed by ultrasonography or radiography. Ultrasonography is used in infants with high-risk factors (e.g., female infants born in the breech position) or an abnormal result on examination. 63–67 Radiographs of newborns with suspected DDH are of limited value because the femoral heads do not ossify until 4 to 6 months of age. After 6 months of age, the FIGURE 43-20. Congenital dysplasia of the left hip with shortening of the femur, as indicated by legs in abduction and asymmetric gluteal and thigh folds (arrows).

Barlow Test

increasing ossification of the femur renders ultrasonog- raphy less reliable, and radiographs are preferred. Treatment of DDH should be individualized and depends on whether the hip is subluxated or dislocated. Subluxation of the hip at birth often resolves without treatment and should be observed for 2 weeks. When sub- luxation persists beyond this time, treatment may be indi- cated and referral is recommended. The best results are obtained if the treatment is begun before changes in the hip structure (e.g., 2 to 3 months) prevent it from being reduced by gentle manipulation or abduction devices. The Pavlik harness is used on newborns (up to 6 months) to maintain the femoral head in the acetabulum. 63 The A feeling of the head of the femur slipping out into the anterior lip of the acetabulum, constitutes a positive Barlow sign.This can be confirmed by abducting the hip by pressing with your index and middle fingers back inward and feeling for movement of the femoral head as it returns to the hip socket. FIGURE 43-21. Examination for developmental dysplasia of the hip. In the newborn both hips should be able to be equally flexed, abducted, and rotated without producing a “click.” A diagnosis of developmental dysplasia of the hip may be confirmed by the Ortolani “click” test (top), in which the involved hip cannot be abducted as far as the opposite one, and there is a “click” as the femoral head moves back into place. A positive Barlow test (bottom) is not diagnostic of developmental dyplasia of the hip, but indicates laxity and a dislocatable progressively, and a need for the baby to be re-examined in the future.