Detecting Developmental Dysplasia of the Hip

Catherine Witt, RNC, MS, NNP

Disclosures

Adv Neonatal Care. 2003;3(2) 

In This Article

Primary Universal Screening: Systematic Physical Examination of the Hips

Universal newborn screening by a properly trained health care provider is critical to early detection and treatment of DDH. Variation in detection rates have been shown in the literature, and are believed to be related to training and experience. Nurse practitioners were more likely to detect anomalies on physical examination, including DDH, than their senior house officer counterparts.[16]

A focused and systematic assessment of the hips should be a routine part of every admission and discharge physical in both the newborn intensive care unit (NICU) and newborn nursery. Nurses may focus on the infant's range of motion, response to diapering, and soft tissue findings. In addition to assessing these findings, nurse practitioners and physicians are typically responsible for manipulating the hips to assess joint stability.

The infant's state, comfort, and relaxation will all enhance the sensitivity of the screening examination for DDH. Although serial examinations may improve detection rates, examinations that are too frequent or too forceful may limit the success rate of the examination.

Optimally, the infant should be in a quiet, relaxed state for the examination. An infant who is upset and crying can tighten the muscles around the hip joint, making the diagnosis of an unstable joint more difficult.[17] Perform the examination on a firm surface. Gently undress the infant from the waist down and remove the diaper to allow unimpaired movement of the legs and complete observation of the extremities.

While the infant is in the supine position, observe for symmetrical spontaneous movements of the hips. Evaluate for abduction to 75° and adduction to 30°; both should occur without difficulty (Fig 6).[1] Evaluate for Allis' or Galeazzi sign by gently flexing the infant's legs, with knees together, resting the soles of the feet on the bed. The height of both knees should be equal. A positive Galeazzi sign, that is, unequal knee height, is an important finding that may signify unequal leg length. This is a sensitive indicator beyond the first 2 months of life.

Note the limited abduction of the thighs when flexed. Reprinted from Cooperman DR, Thompson GH. Neonatal orthopedics. In: Fanaroff AA, Marin RJ, eds. Neonatal-Perinatal Medicine: Diseases of the Fetus and Newborn. 7th ed. St. Louis, MO: Mosby; 2002:1603-1632, with permission.

Next, gently roll the infant to the prone position. Evaluate the gluteal folds for asymmetry, and observe for any restrictions in movement. Abnormalities in inspection may occur singly or in combination, and can be seen in normal and abnormal infants. They include a discrepancy in leg length, an outward turn of the leg, asymmetric gluteal folds, and/or limited abduction.

These findings are classified as an equivocal examination by the current AAP guidelines; carefully document them. They should serve as a warning sign for potential DDH and, at a minimum, should prompt a follow-up examination within 2 to 3 weeks of birth.

The 2 classic maneuvers used to assess neonatal hip stability are the Ortolani and Barlow tests. The Ortolani maneuver moves a dislocated hip back into the socket, creating a distinct, palpable sensation. To perform the Ortolani maneuver, place your index and middle fingers along the greater trochanter of the femur and your thumb along the inner thigh (Fig 7A and B). With the infant's legs in a neutral position, flex the infant's hips 90°. Gently abduct the hips while lifting forward on the femur. A positive Ortolani sign is noted if the hip is dislocated, by a characteristic clunk that is felt as the femoral head slides over the posterior rim of the acetabulum and is reduced.[18]

Ortolani maneuver. (A) Initial downward pressure further dislocates the hip, which then (B) relocates as the thigh is adducted. A palpable “clunk” will be noted. Reprinted from Graham JM. Smith's Recognizable Patterns of Human Deformations. 2nd ed. Philadelphia, PA: Elsevier Science (USA); 1988, with permission.

The Barlow test is a provocative maneuver used to diagnose a dislocatable hip. With the infant in a supine position, the hips are flexed to 90° and abducted. The thigh is grasped, and the leg is gently adducted while applying downward and lateral pressure (Fig 8A and B). A palpable clunk or movement indicates that the femoral head dislocates by sliding over the posterior rim of the acetabulum.[19]

Barlow maneuver. (A) The leg is pulled forward and then (B) adducted in an attempt to dislocate the femur. Reprinted from Graham JM. Smith's Recognizable Patterns of Human Deformations. 2nd ed. Philadelphia, PA: Elsevier Science (USA); 1988, with permission.

The examination for DDH is positive when either the Ortolani or Barlow sign is positive. It is important to remember that if the hip is already completely dislocated and cannot be moved back into the socket, both maneuvers will be negative.

Although both legs can be manipulated at one time, it is optimal to stabilize the pelvis with 1 hand and manipulate 1 leg at a time. Both maneuvers should be performed gently. It does not require a great deal of force to cause the hip joint to dislocate or reduce. Although it is difficult to dislocate a normal hip because of the suction effect of the synovial fluid, damage to the acetabulum or femoral head can result from repeated or forceful examinations.[1]

Carefully document all clinical findings of the examination, and notify the primary care provider. Discuss your findings with parents and develop a well-defined plan of care that can be shared with the family and the follow-up provider. Written documentation is key to assure that early clinical suspicions translate into close clinical follow-up in the critical 2- to 4-week period after birth.

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