//Disorders Of The Lower Extremity Page 1 of 3 Disorders Of The Lower Extremity Normally developed and functional lower extremities permit locomotion with ease and a minimal amount of energy expenditure. A disability resulting from a deformed, shortened, or painful lower limb can be considerable (see Gait and Gait Disturbances, earlier). Many problems of the lower extremities occurring in childhood are congenital and, if they remain unrecognized or are unsuccessfully treated, can result in lifelong disability. Knowledge of the normal anatomy and function of the hip, knee, ankle, and foot is necessary to accurately recognize and treat abnormalities in this region (see Lower Extremity Examination, earlier). Developmental Dislocation of the Hip Developmental dislocation of the hip, formerly referred to as congenital dislocation of the hip, consists of displacement of the femoral head from its normal relationship with the acetabulum. It is a relatively frequent problem, with an incidence of 1 to 2 per 1000 births. It is generally detectable at birth or shortly thereafter. Female infants are affected significantly more frequently than male infants, and unilateral dislocation is twice as frequent as bilateral. Developmental dislocation may be divided into idiopathic and teratogenic types. Idiopathic dislocation is more frequent, and patients often have a positive family history for the defect. Its severity varies from subluxated, to dislocated and reducible, to dislocated and irreducible. This type of developmental dislocation may be related to abnormal intrauterine positioning or restriction of fetal movement in utero, which impedes adequate development and stability of the hip joint complex. The relaxing effect of hormones on soft tissue during pregnancy may also contribute, with affected infants perhaps being more sensitive to the pelvic relaxation effects of maternal estrogen. A history of breech presentation is not uncommon, and these patients often exhibit generalized ligamentous laxity. Teratogenic dislocations of the hip represent a more severe form of the disorder and are probably the result of a germ plasm defect. They occur early in fetal development and result in malformation of both the femoral head and the acetabular socket. Associated congenital anomalies are common in infants whose dislocations are teratogenic, including clubfoot deformity, congenital torticollis, metatarsus adductus, and infantile scoliosis. The importance of careful hip evaluation in the newborn and at early infant visits cannot be overemphasized. Early diagnosis enables prompt institution of treatment and results in a better outcome. A knowledge of the clinical signs and skill in techniques of examination are necessary. Typically, the infant with a dislocated hip has no noticeable difference in the position in which the leg is held, although some affected infants may hold the leg in a position of adduction and external rotation. If the dislocation is unilateral, the skin folds of the thighs and buttocks are often asymmetrical and the involved lower extremity appears shorter than the opposite side (Fig. 21-89, A). This foreshortening is accentuated by holding the hips and knees in 90 degrees of flexion (Galeazzi sign). In patients with bilateral dislocations, this asymmetry is not present. In a truly dislocated hip, the most consistent physical finding is that of limited abduction (see Fig. 21-89, B). Additional diagnostic maneuvers may assist in establishing the diagnosis. In patients with reducible dislocations, the Ortolani sign is positive when a palpable clunk is felt on abduction and internal rotation (relocation) of the hip. The Barlow test is positive if, with the knees flexed and hips flexed to 90 degrees, the hips are gently adducted with pressure applied on the lesser trochanter by the thumb. A palpable clunk indicating posterior dislocation is appreciated if the hip is unstable or dislocated. When the hip is dislocated and irreducible, only limitation of abduction is apparent. http://www.expertconsultbook.com/expertconsult/b/book.do?method=getContent&refresh ... 5/10/2012 //Disorders Of The Lower Extremity Page 2 of 3 Figure 21-89 Developmental dislocation of the hip. A, In cases of unilateral dislocation, the involved extremity is foreshortened and the thigh and groin creases are asymmetric. B, Limited abduction of the involved hip is seen. This is a consistent finding in infants with a dislocated and irreducible hip. C, In this anteroposterior radiograph obtained in a 3-month-old child, the proximal left femur is displaced upward and laterally, and the acetabulum is shallow. The femoral head is not visible on the radiograph because of the delayed ossification associated with developmental hip dislocation. D, In the frog-leg view, the long axis of the affected left femur is directed toward a point superior and lateral to the triradiate cartilage, in contrast with that of the right, which points directly toward this structure. The radiographic findings of a developmental hip dislocation are characteristic. The femoral head is generally located lateral and superior to its normal position, and the acetabulum may be shallow, with lateral deficiency and a characteristic high acetabular index or slope (Fig. 21-89, C and D). Reduction of the dislocated hip is apparent if, on abduction of the hip to 45 degrees, a line drawn through the axis of the metaphysis of the neck crosses the triradiate cartilage (Fig. 21-89, diagram). Because ossification is not evident radiographically until 3 to 6 months of age, ultrasound evaluation of the hip is often helpful in determining the acetabular–femoral head relationships. Furthermore, in developmental dislocation, ossification may be delayed even longer, because normal articulation forces are absent. In teratogenic hip dislocation, there may be hypoplasia of both the acetabular and femoral sides with noncongruent development of one or both of these structures. The early radiographic findings, however, are similar to those already mentioned. Successful correction of congenital hip dislocation depends on early diagnosis and institution of appropriate treatment. In the first 6 months of life, use of a Pavlik harness, which permits gentle motion of the hip in a flexed and abducted position, may achieve and maintain a satisfactory reduction. Between 6 and 18 months of age, gentle closed reduction and immobilization in a spica cast with or without surgical release of the contracted iliopsoas and adductor muscles is indicated. After the age of 18 months, reduction by manipulative measures is http://www.expertconsultbook.com/expertconsult/b/book.do?method=getContent&refresh ... 5/10/2012 //Disorders Of The Lower Extremity Page 3 of 3 difficult owing to contractures of the associated soft tissues. In such instances open reduction is usually indicated. In cases of teratogenic dislocation, underlying maldevelopment makes the outcome less satisfactory, even with optimal management. With early recognition and appropriate treatment, a relatively normal hip with satisfactory function can be anticipated in cases of idiopathic hip dislocation. Failure of concentric reduction or complications such as avascular necrosis of the femoral head, resulting from overzealous attempts at closed reduction in long-standing cases, may result in a lifelong disability characterized by pain and stiffness in the hip; an antalgic, lurching gait; and shortening of the involved limb. Copyright © 2012 Elsevier Inc. All rights reserved. Read our Terms and Conditions of Use and our Privacy Policy. For problems or suggestions concerning this service, please contact: [email protected] http://www.expertconsultbook.com/expertconsult/b/book.do?method=getContent&refresh ... 5/10/2012 //Femoral Anteversion Page 1 of 1 Femoral Anteversion Femoral anteversion may be viewed as a normal variation of lower extremity positioning in the developing child. In utero and at birth, the femoral neck sits in an anteverted position relative to that of the adult. During childhood it remodels to a position of slight anteversion and normal alignment of the lower extremities. In certain children, however, delayed rotational correction may result in persistent intoeing. An unsightly gait, kicking of the heels, and tripping on walking or running are frequent related complaints. There may be a history of sitting on the floor with knees bent and the lower legs turned outward in a reversed tailor position. In general, the condition is bilateral and is not associated with other musculoskeletal problems. On examination, the child is noted to stand with the thighs, knees, and feet all turned inward. An increase in internal rotation over external rotation is apparent on assessment of range of motion of the hip (Fig. 21-92). Radiographic findings are normal. No treatment is indicated, other than reassurance that the condition will correct with growth and instructions to avoid sitting in the predisposing position. Figure 21-92 Femoral anteversion. A, The condition occurs bilaterally, and in the standing view, both legs appear to turn inward from the hip down. B, On assessment of range of motion, the degree of internal rotation of the hips is found to be greater than normal. (Courtesy Michael Sherlock, MD, Lutherville, Md.) Copyright © 2012 Elsevier Inc. All rights reserved. Read our Terms and Conditions of Use and our Privacy Policy. For problems or suggestions concerning this service, please contact: [email protected] http://www.expertconsultbook.com/expertconsult/b/book.do?method=getContent&refresh