Orthopedics
All newborn babies should be examined for evidence of hip dysplasia, spinal dysraphism, and lower and upper extremity deformities. 1
Look at the extremities, and check for asymmetry or an abnormal appearance. Look at the baby when crying to determine if he or she moves all extremities. Gently examine the joints and their range of motion. Finally, stimulating the extremities should result in some kind of response, usually withdrawal. 2
4. A premature newborn infant receiving ventilator support in the NICU has decreased movement in the right lower extremity. What diagnostic tests may be appropriate?
Neonatal osteomyelitis or fracture need to be ruled out. Baseline laboratory testing should be considered (e.g., complete blood count and C-reactive protein) as part of the evaluation for possible joint infections, which are not uncommon in this setting. If an osteomyelitis is suspected, a blood culture should always be obtained. These tests may not be rewarding because infants may develop infection without abnormalities in laboratory values. Plain radiographs of the entire extremity should be obtained to help detect a subtle fracture that may not be apparent on clinical examination. Radiographs are often normal in the early phases of bone and joint infection. In this setting bone and joint infections most often involve more than one site. Therefore careful clinical assessment to detect subtle joint effusions or swelling over long bones is indicated. Often an ultrasound scan is helpful in confirming a joint effusion in the hip because overlying muscle may mask the usual clinical findings. A technetium-99 bone scan is very useful in detecting other sites of multicentric infection. 3
5. The initial evaluation of a first-born infant reveals multiple stiff joints in both the upper and lower extremities and thin, tapered, and “shiny” fingers. What is the main diagnostic consideration?
Arthrogryposis multiplex congenita is a clinical syndrome characterized by poor development of the joints in utero leading to multiple contractures. This does not appear to be a hereditary condition, and there is no increased risk in siblings of the same family. Many mothers report decreased fetal movement in utero. On clinical examination the limbs are usually symmetric. Joints may have either flexion or extension contractures. There is decreased active and passive motion of the affected joints. The normal skin creases are usually absent, and the skin is taut and glossy. Dimpling at the joints may be present. There is atrophy of the limbs. Often the hips are dislocated, and clubfoot (i.e., talipes equinovarus) or congenital vertical talus affects the feet. The upper extremities are usually internally rotated at the shoulder, with elbow flexion or extension contractures. There are often radial head dislocations. The forearms are pronated with adduction deformity of the thumbs. Delivery may be difficult as a consequence of the stiff elbow and knee joints. This may result in birth fractures of the humerus and the femur. General health is not affected by this syndrome, although patients often exhibit minor respiratory difficulties and failure to thrive as newborns. 4
7. A newborn infant is noted to have external rotation of the lower extremities at rest, with little spontaneous movement and bilateral foot deformities. What radiographs should be ordered?
Both spine and pelvis radiographs should be ordered. The abnormalities described can result from anomalies of the spine or the lower extremities. 5
8. A newborn child is suspected of having a genetic skeletal dysplasia. What is the most critical orthopedic radiographic examination?
The most important radiograph is the lateral cervical spine. More than 150 distinct osteochondrodysplasias have been identified. Each has distinctive features, but many also have similar radiographic findings. One of the most common is agenesis or hypoplasia of the upper cervical spine elements. This can lead to instability and places the child at great risk of spinal cord injury during ordinary handling. Detection of cervical instability is mandatory to allow proper stabilization and protection. 6
DDH is a maldevelopment of the hip joint characterized by a spectrum of pathology ranging from instability of the hip to irreducible dislocation. 7
CDH is an outdated term; DDH is preferred because it reflects the evolutionary nature of hip problems in infants in the first months of life. The overt pathologic process may not be present at birth, and periodic examination of the infant’s hip is recommended at each routine well-baby visit until the age of 1 year ( Fig. 16-1). 8
Figure 16-1 Congenital dislocation of the hip. (Netter illustration from www.netterimages.com. © Elsevier Inc. All rights reserved.)
The hip abduction, Ortolani, Barlow, and Galeazzi tests are recommended. 9
KEY POINTS: DEVELOPMENTAL DYSPLASIA OF THE HIP IN NEWBORNSInfants should have symmetric hip abduction. Having asymmetry in hip abduction could be a sign of a dislocated hip. 10
13. How do you perform an Ortolani exam?
It is performed with the child in the supine position. Beginning with the hips flexed 90 degrees and adducted to the midline, the examiner places the index finger on the greater trochanter and the thumb on the inside of the thigh, then gently abducts the hip and lifts up on the greater trochanter. If the hip is dislocated and reducible, a palpable sensation will be felt as the hip reduces into the acetabulum (known as an Ortolani-positive hip) ( Fig. 16-2). 11
14. What does it mean to describe a hip as “Ortolani positive”?
The Ortolani examination is a reduction maneuver. Therefore an Ortolani-positive hip is a hip that is dislocated in its resting state and reducible with gentle manipulation. A simple way to remember this: Think of the O in Ortolani meaning that a hip is “out,” or dislocated, when you start the examination. 12
It is performed with the child supine on the examination table. The hip is flexed 90 degrees and adducted just beyond midline. Gentle downward pressure is then applied to the hip through the knee. The sensation of the femoral head sliding out of the acetabulum indicates a Barlow-positive hip. 13
The Barlow examination is a provocative maneuver. A Barlow-positive hip is normally reduced but can be subluxed. A normal hip will not subluxate and is Barlow negative. 14
