Anomalies of the Upper and Lower Limbs

Anomalies of the Shoulder Girdle and Upper Limbs

Congenital Elevation of the Scapula

Sprengel deformity, as congenital elevation of the scapula is also known, may be unilateral or bilateral. It is marked by the appearance of a scapula that is small, high in position, and rotated with its inferior edge pointing toward the spine—features that are easily identified on an anteroposterior radiograph of the shoulder or chest (Fig. 32.1). The left shoulder is the most commonly affected, and about 75% of all cases are observed in girls. Some cases of this anomaly are inherited in an autosomal dominant manner, although most cases are sporadic. A familial form of the Sprengel deformity is known as Corno disease. The finding of a congenitally elevated scapula is important because of this condition’s frequent association with other anomalies, such as congenital scoliosis, fused ribs, spina bifida, and fusion of the cervical or upper thoracic vertebrae, the latter deformity known as Klippel-Feil syndrome, also a congenital disorder (Fig. 32.2) caused by mutations in the GDF3 and GDF6 genes. Furthermore, there is sometimes a bony connection between the elevated scapula and one of the vertebrae (usually the C5 or C6 vertebra), creating what is known as the omovertebral bone (Fig. 32.3).

Madelung Deformity

This developmental anomaly of the distal radius and carpus, originally described by the German surgeon Otto Madelung in 1879, usually manifests in adolescent girls presenting with pain in the wrist and decreased range of motion but with no history of previous trauma or infection. Today, the term Madelung deformity is often used to describe a variety of conditions in the wrist marked by premature fusion of the distal physis of the radius, with consequent deformity of the distal ulna and wrist. From the etiologic viewpoint, these abnormalities can be divided into posttraumatic deformities, dysplasias, and idiopathic conditions. A genetic cause has also been proposed. Association with mesomelic dwarfism (e.g., Leri-Weill dyschondrosteosis, caused by deletion or duplication of the SHOX gene located within the band Xp22.3 of the chromosome X) and a mutation on the X chromosome (e.g., Turner syndrome) has also been described. The posttraumatic deformity may occur after repetitive injury or after a single event that disrupts the growth of the distal radius. Among the bone dysplasias associated with Madelung deformity are multiple hereditary cartilaginous exostoses, Ollier disease, achondroplasia, multiple epiphyseal dysplasia, and the mucopolysaccharidoses including Hurler and Morquio syndromes.

On physical examination, the hand is translated volarly to the long axis of the forearm and there is dorsal subluxation of the ulna. A decreased range of motion limits supination, dorsiflexion, and radial deviation, but pronation and palmar flexion are usually preserved.

The radiographic criteria for the diagnosis of Madelung deformity were proposed by Dannenberg and colleagues (Table 32.1). The posteroanterior and lateral projections of the distal forearm and wrist are sufficient to demonstrate any of the abnormalities associated with this deformity (Figs. 32.4 and 32.5) .

Surgical treatment of Madelung deformity is indicated for pain relief and cosmetic improvement. A variety of procedures are available. These include ligament release (Vickers physiolysis), wedge osteotomy, Carter-Ezaki dome osteotomy, and radioscaphocapitate arthrodesis. Occasionally, a Darrach or a Suavé-Kapandji procedure is indicated.

Anomalies of the Pelvic Girdle and Hip

An overview of the most effective radiographic projections and radiologic techniques for evaluating the most common anomalies of the pelvic girdle and hip is presented in Table 32.2.

Congenital Hip Dislocation (Developmental Dysplasia of the Hip)

The hip joint is the most frequent site of congenital dislocations. The condition occurs with an incidence of 1.5 per 1,000 births and eight times more often in girls than in boys. In unilateral dislocation, the left hip is involved twice as often as the right, and bilateral dislocation occurs in more than 25% of affected children. More commonly encountered in white than in black persons, the condition is very common in Mediterranean and Scandinavian countries; it is almost unknown in China, which may be explained in part by the Chinese custom of carrying the infant on the mother’s back with its hips flexed and abducted.

The criteria for the diagnosis of congenital dislocation of the hip (CDH) include physical and imaging findings. Certain clinical signs have been identified that are helpful in the evaluation of newborns and infants for possible CDH (Table 32.3).

Radiographic Evaluation

Each of the stages of CDH—dysplasia of the hip, subluxation of the hip, and dislocation of the hip—has a characteristic radiographic presentation. The term congenital hip dysplasia, first introduced by Hilgenreiner in 1925, refers to delayed or defective development of the hip joint leading to a deranged articular relationship between an abnormal acetabulum and a deformed proximal end of the femur (Fig. 32.6). The condition is considered

a precursor of subluxation and dislocation of the hip, although some authorities use the term developmental dysplasia of the hip (DDH) to denote all stages of CDH. In congenital subluxation of the hip, there is an abnormal relationship between the femoral head and the acetabulum, but the two are in contact (Fig. 32.7). Congenital dislocation of the hip, however, is marked by the femoral head’s complete loss of contact with the acetabular cartilage; the proximal femur is displaced most often superiorly, but lateral, posterior, and posterolateral dislocation may also be seen (Fig. 32.8).

FIGURE 32.1 Sprengel deformity. (A) Anteroposterior radiograph of the left shoulder of a 1-year-old boy demonstrates a high position of the left scapula typical of Sprengel deformity. (B) Anteroposterior and (C) oblique radiographs of the left shoulder of a 58-year-old woman, who remembers having “a crooked shoulder blade” since early childhood, show congenital elevation of the left scapula (arrows).

FIGURE 32.2 Klippel-Feil syndrome and Sprengel deformity. Anteroposterior radiograph of the left shoulder of a 13-year-old boy with Klippel-Feil syndrome shows an elevated scapula (arrow).

FIGURE 32.3 Klippel-Feil syndrome and Sprengel deformity. Posteroanterior radiograph of the cervical and upper thoracic spine in a 37-year-old woman with Sprengel deformity associated with Klippel-Feil syndrome (fusion of the cervical vertebrae) shows the omovertebral bone connecting the elevated right scapula and the C5 vertebra.

TABLE 32.1 Radiographic Criteria for the Diagnosis of Madelung Deformity

Changes in the Radius
	Double curvature (medial and dorsal) Decrease in bone length Triangular shape of the distal epiphysis Premature fusion of the medial part of the distal physis, associated with medial and volar angulation of the articular surface Focal radiolucent areas along the medial border of bone Exostosis at the distal medial border
Changes in the Ulna
	Dorsal subluxation Increased density (hypercondensation and distortion) of the ulnar head Increase in bone length
Changes in the Carpus
	Triangular configuration with the lunate at the apex Increase in distance between the distal radius and the ulna Decrease in carpal angle
Modified from Dannenberg M, Anton JI, Spiegel MB. Madelung’s deformity. Consideration of its roentgenological diagnostic criteria. Am J Roentgenol 1939;42:671.

FIGURE 32.4 Madelung deformity. (A) Posteroanterior radiograph of the left wrist of a 21-year-old woman shows a decrease in the length of the radius, the distal end of which has assumed a triangular shape. This is associated with a triangular configuration of the carpus, with the lunate at the apex wedged between the radius and the ulna. (B) Lateral radiograph demonstrates dorsal subluxation of the ulna (arrow).

FIGURE 32.5 Madelung deformity. (A) Posteroanterior and (B) lateral radiographs of the left wrist of a 42-year-old woman show characteristic changes of this anomaly including decreased length of the radius, elongation of the ulna associated with dorsal subluxation, and triangular configuration of the carpus with lunate wedged between the radius and the ulna. (Courtesy of Robert M. Szabo, MD, Sacramento, California).

TABLE 32.2 Most Effective Radiographic Projections and Radiologic Techniques for Evaluating Common Anomalies of the Pelvic Girdle and Hip

Projection/Technique	Crucial Abnormalities
*Congenital Hip Dislocation*
Anteroposterior of pelvis and hips	Determination of
		Hilgenreiner Y-line Acetabular index Perkins-Ombredanne line Shenton-Menard line (arc) C-E angle of Wiberg
	Ossification center of capital femoral epiphysis Relations of femoral head and acetabulum
Anteroposterior of hips in abduction and internal rotation Arthrography	Andrén-von Rosen line Congruity of the joint Status of
		Cartilaginous limbus (limbus thorn) Ligamentum teres Zona orbicularis
CT (alone or with arthrography) Ultrasound	Relations of femoral head and acetabulum Superior, lateral, or posterior subluxation Position of femoral head in acetabulum Status of
		Acetabular roof Cartilaginous limbus
*Developmental Coxa Vara*
Anteroposterior of pelvis and hips	Varus angle of femoral neck and femoral shaft
*Proximal Femoral Focal Deficiency*
Anteroposterior of hip and proximal femur	Shortening of femur Superior, posterior, and lateral displacement of proximal femoral segment
Arthrography	Nonossified femoral head
*Legg-Calvé-Perthes Disease*
Anteroposterior and frog-lateral of hips	Osteonecrosis of femoral head as indicated by crescent sign and subchondral collapse Gage sign Subluxation of femoral head Horizontal orientation of growth plate Calcifications lateral to epiphysis Cystic changes in metaphysis Sagging rope sign
Arthrography	Incongruity of hip joint Thickness of articular cartilage
Radionuclide bone scan	Decreased uptake of isotope (earliest stage) Increased uptake of isotope (late stage)
CT and MRI	Incongruity of hip joint Osteonecrosis
*Slipped Capital Femoral Epiphysis*
Anteroposterior of hips	Loss of Capener triangle sign Periarticular osteoporosis Widening and blurring of growth plate Decreased height of femoral epiphysis Absence of intersection of epiphysis by line tangent to lateral cortex of femoral neck Herndon hump Chondrolysis (complication)
Frog-lateral of hips	Absence of intersection of epiphysis by line tangent to lateral cortex of femoral neck Actual slippage (displacement) of femoral epiphysis
Radionuclide bone scan and MRI	Osteonecrosis (complication)
C-E, center-edge; CT, computed tomography; MRI, magnetic resonance imaging.

TABLE 32.3 Clinical Manifestations of Congenital Dislocation of the Hip

Limited abduction of the flexed hip (due to shortening and contraction of hip adductors)

Increase in depth or asymmetry of the inguinal or thigh skinfolds

Shortening of one leg

Allis or Galeazzi sign^a—lower position of knee of affected side when knees and hips are flexed (due to location of femoral head posterior to acetabulum in this position)

Ortolani “jerk” sign (“clunk of entry” or reduction sign)

Barlow test (“clunk of exit” or dislocation sign)

Telescoping or pistoning action of thighs^a (due to lack of containment of femoral head within acetabulum)

Trendelenburg test^a—dropping of normal hip when child, standing on both feet, elevates unaffected limb and bears weight on affected side (due to weakness of hip abductors)

Waddling gait^a

^aThis finding can occur in older children.

Measurements

In contrast to an adult hip, the relationship between the femoral head and the acetabulum in a newborn’s hip cannot be assessed by direct visualization because the femoral head is not ossified, and as a cartilaginous body, it is not visible on conventional radiographs. The ossification center first appears between the ages of 3 and 6 months, and a delay in its appearance should be viewed as an indication of congenital hip dysplasia. The neck of the femur must therefore be used for ascertaining this relationship. The anteroposterior radiograph of the pelvis serves as the basis for determining several indirect indicators of the relationship between the femoral head and the acetabulum. To obtain accurate measurements, however, proper positioning of the infant is imperative; the lower extremities should be extended in the neutral position and longitudinally aligned, whereas the central ray should be directed toward the midline, slightly above the pubic symphysis, to ensure the symmetry of both halves of the pelvis. The measurements used to evaluate the relation of the femoral head to the acetabulum are the following (Fig. 32.9):

FIGURE 32.6 Congenital hip dysplasia. Anteroposterior radiograph of the pelvis of a 1-year-old boy shows a slightly flattened acetabulum and delayed appearance of the ossification center for the right femoral epiphysis; that of the left epiphysis is normally centered over the triradiate cartilage.

FIGURE 32.7 Congenital hip dysplasia. Anteroposterior radiograph of the pelvis of a 1-year-old girl shows congenital superolateral subluxation of the left hip. Note the slightly smaller size of the left femoral epiphysis.

The Hilgenreiner line or Y-line, which is drawn through the superior part of the triradiate cartilage, is itself a valuable indicator of femoroacetabular relations and serves as the basis for all other indicators.
The acetabular index, which is an angle formed by a line tangent to the acetabular roof and the Y-line, cannot alone be diagnostic of dislocation because it can occasionally exceed 30 degrees in normal subjects. Generally, however, values greater than 30 degrees are considered abnormal and indicate impending dislocation. Some investigators propose that only angles in excess of 40 degrees are significant.
The Perkins-Ombredanne line, which is drawn perpendicular to the Y-line through the most lateral edge of the ossified acetabular cartilage, is helpful in determining subluxation and dislocation of the hip. The intersection of this line with the Y-line creates four quadrants; normally, the medial aspect of the femoral neck or the ossified capital femoral epiphysis falls in the lower medial quadrant.

The Shenton-Menard line, which forms a smooth arc through the medial aspect of the femoral neck and the superior border of the obturator foramen, may be interrupted in subluxation or dislocation of the hip. Even under normal circumstances, however, the arc may not be smooth if the radiograph is obtained with the hip in external rotation and adduction.

FIGURE 32.8 Congenital hip dislocation. Anteroposterior radiograph of the pelvis of a 2-year-old boy demonstrates complete superolateral dislocation of the right hip. Note the abnormal position of the center of ossification in relation to the acetabulum compared with the normal left hip.

FIGURE 32.9 Measurements helpful to evaluate the relation of the femoral head to the acetabulum. (A) The Hilgenreiner line or Y-line is drawn through the superior part of the triradiate cartilage. In normal infants, the distance represented by a line (ab) perpendicular to the Y-line at the most proximal point of the femoral neck should be equal on both sides of the pelvis, as should the distance represented by a line (bc) drawn coincident with the Y-line medially to the acetabular floor. In infants aged 6 to 7 months, the mean value for the distance (ab) has been determined to be 19.3 ± 1.5 mm; the distance for (bc) is 18.2 ± 1.4 mm. The acetabular index is an angle formed by a line drawn tangent to the acetabular roof from point (c) at the acetabular floor on the Y-line. The normal value of this angle ranges from 25 to 29 degrees. The Shenton-Menard line is an arc running through the medial aspect of the femoral neck and the superior border of the obturator foramen. It should be smooth and unbroken. (B) The Perkins-Ombredanne line is drawn perpendicular to the Y-line through the most lateral edge of the ossified acetabular cartilage, which actually corresponds to the anteroinferior iliac spine. In normal newborns and infants, the medial aspect of the femoral neck or the ossified capital femoral epiphysis falls in the lower inner quadrant. The appearance of either of these structures in the lower outer or upper outer quadrant indicates subluxation or dislocation of the hip.

The Andrén-von Rosen line, which is drawn on a radiograph obtained with the hips abducted 45 degrees and internally rotated, describes the relation of the longitudinal axis of the femoral shaft to the acetabulum (Fig. 32.10). In dislocation or subluxation of the hip, this line bisects or falls above the anterosuperior iliac spine.

After the capital femoral epiphysis achieves full ossification at approximately 4 years of age, a diagnosis of gross displacement can usually be made without difficulty. The evaluation of subtle hip dysplasias, however, can be aided by another parameter of the relation of the femoral head to the acetabulum, the center-edge (C–E) angle of Wiberg (Fig. 32.11). Determination of this angle is most useful after full ossification of the femoral head because its relationship to the acetabulum is then fully established.

Arthrography and Computed Tomography

Aside from conventional radiography, hip arthrography is the most useful technique for evaluating CDH. During the procedure, radiographs are routinely obtained with the hip in the neutral (Fig. 32.12A) and frog-lateral positions (Fig. 32.12B), as well as in abduction, adduction, and internal rotation. In subluxation, the femoral head lies lateral to just below the margin of the acetabular cartilaginous labrum, and the joint capsule is usually loose (Fig. 32.13). In complete dislocation, the femoral head lies superior and lateral to the edge of the labrum (Fig. 32.14). Deformities may also be encountered in the cartilaginous limbus, a structure lying between the femoral head and the acetabulum. In advanced stages, it may be inverted and hypertrophied, thus making the reduction impossible. Moreover, the portion of the capsule lying medial to the femoral head is usually constricted to form an isthmus with a “figure-eight” appearance.

FIGURE 32.10 The Andrén-von Rosen line. (A) With at least 45 degrees of hip abduction and internal rotation, the line is drawn along the longitudinal axis of the femoral shaft. In normal hips, it intersects the pelvis at the upper edge of the acetabulum. (B) In subluxation or dislocation of the hip, the line bisects or falls above the anterosuperior iliac spine.

Computed tomography (CT), either alone (Fig. 32.15) or with arthrography, is also a frequently used modality in the evaluation of CDH. In subluxation or dislocation, the congruity of the acetabulum and the femoral head, which is normally centered over the triradiate cartilage, is disturbed (Fig. 32.16). CT has proved to be the most accurate technique for determining the degree of subluxation or dislocation. It is also an essential modality for monitoring the progress of CDH treatment. In the adult patient, it provides an effective method to evaluate the undercoverage of the femoral head by bony acetabulum (Fig. 32.17).

FIGURE 32.11 Angle of Wiberg. The C-E angle of Wiberg is helpful in evaluating the development of the acetabulum and its relation to the femoral head. A baseline is projected, connecting the centers of the femoral heads. The C-E angle is formed by two lines originating in the center of the femoral head, one drawn perpendicular to the baseline into the acetabulum, and the other connecting the center of the femoral head with the superior acetabular lip. Values below the lowest normal value given for each age group indicate hip dysplasia.

FIGURE 32.12 Arthrogram of a normal hip. (A) Arthrogram of the right hip in the neutral position in a 5-month-old boy shows contrast agent accumulating in the large recesses medial and lateral to the constriction produced by the orbicular ligament (arrow). Note the smoothness and even thickness of the cartilage covering the femoral head. (B) On the frog-lateral view, contrast is seen outlining the edge of the cartilaginous labrum (arrow). The ligamentum teres can be seen medial to the femoral head, extending from the inferior portion of the acetabulum.

FIGURE 32.13 Arthrogram of congenital hip dysplasia. (A) Arthrogram of the right hip in the neutral position in a 1-year-old girl with congenital subluxation of the hip shows the typical displacement of the hip lateral to but below the acetabular labrum. There is accumulation of contrast agent in the stretched capsule (arrow), and the ligamentum teres is elongated. (B) In the frog-lateral position, the head moves more deeply into the acetabulum, but subluxation is still present.

FIGURE 32.14 Arthrogram of congenital hip dislocation. (A) Anteroposterior radiograph of the right hip in an 8-year-old girl demonstrates complete superolateral dislocation of the femoral head. Note the shallow acetabulum. (B) Arthrogram of the hip shows a deformed cartilaginous limbus and stretching of the ligamentum teres. The femoral head lies superior and lateral to the edge of the cartilaginous labrum. Note the accumulation of contrast agent in the loose joint capsule.

FIGURE 32.15 CT of the normal hips. Axial section of both hips in a 19-monthold infant shows good congruity of the acetabula and femoral heads, which are centered over the triradiate cartilage.

FIGURE 32.16 CT of congenital hip dislocation. Axial section through the proximal femora and hips of a 6-month-old boy shows posterolateral dislocation of the left hip. The right hip is normal.

FIGURE 32.17 3D CT of congenital hip dysplasia. 3D reconstructed CT image of the pelvis of a 32-year-old man with congenital bilateral hip dysplasia shows undercoverage of the femoral heads by bony acetabula.

Ultrasound

In the past decade, ultrasound has become one of the most effective techniques to diagnose and evaluate congenital hip dysplasia. It is performed with the patient at rest, and during motion and stress. A lateral approach is widely used, with the infant supine or in the lateral decubitus position. Scanning is performed in the coronal plane with the hips extended or flexed (see Fig. 31.17). In the axial plane, the thighs are in 90 degrees of flexion, and images are obtained with and without stress. The osseous and cartilaginous components of the hip joint are well demonstrated on the displayed images, and acetabular coverage of the femoral head can be assessed. In addition, the slope of the acetabulum (α-angle) can be measured with respect to the iliac line. An angle of 60 degrees or more is normal. An angle 50 to 60 degrees is considered physiologic before age 3 months but needs to be followed up by repeat studies. Values less than 50 degrees are abnormal at any age. A second angle (β-angle) is formed by the iliac line and a line drawn from the labrum to the transition point between the iliac bone and the bony acetabulum. This measurement is indicative of the acetabular cartilaginous roof coverage and is secondary in significance to the α-angle. The smaller the β-angle, the less the cartilaginous coverage because of a better acetabular bony containment of the femoral head. The dynamic study, first described by Harcke in 1984, incorporates the use of real-time ultrasound visualization of the hip joint. The purpose of this technique is to demonstrate the instability. It is performed in the transverse flexion projection and consists of a Barlow maneuver to try to displace, sublux, or dislocate an apparently well-seated femoral head.

Recently, three-dimensional (3D) sonographic evaluation of DDH has been attempted. This technique permits evaluation of the osseous and fibrocartilaginous acetabulum and its relationship to the femoral head in a global fashion (gestalt) without the need for detailed acetabular angle measurements. The information obtained can be stored for later review, analysis, and additional reconstructions with different parameters. The computer-generated sagittal plane image offers a unique view of the hip that is unobtainable with conventional sonography (Fig. 32.18). The generated spatial-revolving image likewise yields an informative craniocaudal (bird’s eye) view of the infant hip (Fig. 32.19). The 3D appearance of the revolving image is enhanced by the transparency of the reconstruction, in contrast to the contour reconstructions available with 3D CT.

Magnetic Resonance Imaging

In the past decade, the role of magnetic resonance imaging (MRI) in evaluation of the developmental dysplasias of the hip has evolved. Although the various investigators do not recommend this technique for routine use, nevertheless they point out the beneficial features of this modality such as qualitative information not available through radiography, particularly in the patients in whom the conservative treatment failed. Conversely, some authors suggest that MRI provides accurate anatomical information regarding the labrum, the ligamentum teres, the intraarticular fat pad (pulvinar), the transverse ligament, and the iliopsoas tendon. In addition, in some studies of the young adults, MRI studies demonstrated improved detection and characterization of DDH by providing morphologic information about acetabular deficiency. This technique also allowed evaluation of potential associated injuries to the articular cartilage, the labrum, and the ligamentum teres (Fig. 32.20).

Classification

Dunn has proposed a classification of CDH based primarily on the shape of the acetabular margins, the gross contour of the femoral head, and whether there is eversion or inversion of the limbus:

Type I: This is usually seen in neonates. The changes along the acetabular margins are mild. The femoral head, which is anteverted but spherically normal, is not completely covered by acetabular cartilage. This may lead to variable instability, particularly in extension and adduction of the hip. The labrum may also be deformed.

Type II: The hips are subluxed, and the cartilaginous labrum shows eversion. The femoral head is normally anteverted but shows a loss of sphericity. The acetabulum is shallower than in type I, and the failure of the acetabular roof to ossify laterally leads to an increased acetabular angle.

Type III: There is significant deformity of the acetabulum and femoral head, which is posterosuperiorly dislocated, leading to the formation of a false acetabulum by eversion of the labrum. The limbus is hypertrophied, and the ligamentum teres is elongated and pulled, bringing with it the transverse acetabular ligament. This situation compromises the acetabular space, precluding complete reduction.

In 1979, Crowe and colleagues proposed classification of congenital hip dislocation in the adults based on the extent of proximal migration of the femoral head. Grade I comprises those cases showing minimal abnormal development of the femoral head and acetabulum with less than 50% subluxation; grade II—those cases showing abnormal development of the acetabulum with 50% to 75% subluxation; grade III—when the acetabulum is developed without a roof and there is full dislocation in the hip joint (75% to 100%), with false acetabulum developing at the site of dislocated femoral head; and grade IV—when the femur is positioned high on the pelvis (high hip dislocation, 100% dislocation).

Treatment

The principle behind conservative treatment is to reduce the dislocation of the femoral head, by means of a flexion-abduction maneuver, for a period sufficient enough to permit proper growth of the head and acetabulum, which in turn ensures a congruent and stable hip joint. This approach is usually taken in the very early stages of CDH and in infants younger than age 2 years; it includes splinting, such as with the Frejka splint or Pavlik harness, as well as various traction procedures (Fig. 32.21). Colonna or buck skin traction is usually used in children 2 months to 12 years of age, with a well-padded spica cast applied simultaneously to the unaffected side. Interval radiographs are obtained to monitor the progress of the traction and the descent of the femoral head. A system for this purpose, composed of various traction “stations,” has been described by Gage and Winter (Fig. 32.22). It has been reported that the achievement of “station +2” by means of skeletal traction, before further treatment by open or closed reduction, is associated with a far smaller frequency of osteonecrosis of the femoral head.

When the conservative approach fails, the child is too old for conservative treatment, or the abnormalities are too extensive, then surgical management is indicated. Radiologic assessment of the hip, in which CT examination plays the leading role, is mandatory before surgical intervention because it provides the surgeon with excellent images of the anatomy of the hip, particularly the size of the femoral head, its relation to the acetabulum, and the acetabular configuration. The information regarding these structures may contraindicate the use of certain surgical procedures.

Several surgical techniques are now used for treatment of congenital hip dysplasia. Their common goal is to achieve better coverage of the femoral head. These surgical procedures can be divided into four categories: shelf operations, in which bone grafts are used to extend the acetabular roof; acetabuloplasties, in which the acetabular roof is mobilized and turned down; pelvic osteotomies, in which the acetabulum is redirected; and pelvic displacement osteotomies, in which the femoral head is positioned beneath the displaced bony portion of the pelvis. Capsulorrhaphy consists of removal of the excess of the stretched joint capsule, combined with a femoroplasty and/or acetabuloplasty. Femoral varus derotational osteotomy is performed to correct an excessive anteversion of the neck and valgus deformity. It involves a varus angulation of the proximal femur, with or without rotation, to redirect the femoral head into the acetabulum (Fig. 32.23). The most popular procedure is the Salter osteotomy of the innominate bone, which may be combined with simultaneous derotational varus osteotomy of the femoral neck. It is usually performed in children aged 1 to 6 years. The principle of this technique is to redirect the abnormal orientation of the acetabulum, which in children with CDH faces more anterolaterally, thus rendering the hip stable only in abduction, flexion, and internal rotation. This redirection is accomplished by displacing the entire acetabulum anterolaterally and downward, without changing its shape or capacity, by means of a triangular bone graft (Fig. 32.24). Pemberton osteotomy is an incomplete transiliac osteotomy, hinging the anterolateral acetabular roof on the flexible triradiate cartilage. This procedure is indicated when there is an elongated, dysplastic acetabulum; however, it should be performed only in children younger than age 7 years when there is flexibility

in the triradiate cartilage and when growth remains for remodeling of the joint surfaces. Steele triple innominate osteotomy is usually indicated for children older than age 6 to 8 years who have an immobile symphysis pubis. In addition to Salter osteotomy, osteotomies of the inferior and superior pubic rami are performed. The acetabulum is brought forward and rotated in the frontal plane, avoiding external rotation. The Chiari pelvic osteotomy is usually reserved for older children. This is a displacement osteotomy that essentially provides a shelf or buttress to limit further proximal subluxation of the femoral head. This procedure displaces the femoral head medially and increases the weight-bearing surface of the head by producing an overhanging superior acetabular ledge. This technique may also be combined with a varus derotational osteotomy of the femoral neck. Ganz osteotomy, also known as Bernese periacetabular osteotomy, is usually performed in older children and adolescents and occasionally in adults. The principle behind the procedure is to allow anterior and lateral rotation and medialization of the hip without violation of the posterior column of the hemipelvis. Osteotomies are performed around the acetabulum (complete osteotomy of the pubis and biplanar osteotomy of the ilium); however, the cut through the posterior column of the ischium is incomplete. The acetabular fragment is rotated anteriorly and laterally (maintaining anteversion) and is then medialized. This procedure provides excellent femoral head coverage and acetabular mobility.

FIGURE 32.18 Ultrasound of congenital hip dysplasia. (A) On the coronal 3D ultrasound image of the left hip in a 3-day-old girl (lower left) the acetabulum (A) appears shallow, and subluxation of the femoral head can be observed at the intersection of the ilium (I) line with the medial third of the femoral head (FH). On the reconstructed axial image (upper left), the femoral head is subluxated but still in contact with the acetabulum. On the sagittal image (upper right), only the peripheral segment of femoral head is visualized. (B) A sagittal image of a normal left hip (left) is shown for comparison. Note that femoral head (FH) is centered over the ilium line (I). A sagittal image of a subluxated head (right) clearly shows distortion of femoral head-ilium line relationship. LAT, lateral; INF, inferior; SUP, superior. (From Gerscovich EO, Greenspan A, Cronan MS, Karol LA, McGahan JP. Three-dimensional sonographic evaluation of developmental dysplasia of the hip: preliminary findings. Radiology 1994;190:407-410.)

FIGURE 32.19 3D ultrasound of congenital hip dysplasia. (A) Craniocaudal projection (bird’s eye view) of a normal left hip shows the ilium (I) projecting over the midportion of the femoral head (FH) (arrows outline its contour). (B) Craniocaudal projection of a subluxated left hip shows that the ilium (I) projects over the medial portion of the femoral head (FH) (arrows outline its contour). The femoral head is laterally displaced. LAT, lateral; ANT, anterior; POST, posterior. (From Gerscovich EO, Greenspan A, Cronan MS, Karol LA, McGahan JP. Three-dimensional sonographic evaluation of developmental dysplasia of the hip: preliminary findings. Radiology 1994;190:407-410.)

FIGURE 32.20 MRI of congenital hip dysplasia. (A) Coronal T2-weighted MRI of a 5-year-old boy with left DDH demonstrates a shallow left acetabulum, uncoverage of the femoral head, and a superiorly rotated and torn labrum (arrow). (B) Coronal T1-weighted MRI of a 5-month-old boy with left DDH demonstrates lateral subluxation and uncoverage of the femoral head, a dysplastic and shallow acetabulum, an everted and hypertrophied labrum (arrow), and hypertrophy of the pulvinar and transverse ligament (arrowheads).

FIGURE 32.21 Treatment of congenital hip dysplasia. (A) Anteroposterior radiograph of the pelvis in a 1-year-old boy demonstrates the typical appearance of congenital dislocation of the left hip. (B) After conservative treatment with a Pavlik harness at age 2 years, there is still subluxation. Note the broken Shenton-Menard arc. At age 3 years, after further conservative treatment by skin traction and application of a spica cast, there is almost complete reduction of subluxation, as demonstrated by contrast arthrography (C). (D) CT scan, however, demonstrates some minimal residual lateral displacement of the femoral head, as evidenced by the medial accumulation of contrast.

FIGURE 32.22 The Gage and Winter system. This measurement of stations for monitoring the progress of treatment by traction and the descent of the femoral head is based on the position of the proximal femoral metaphysis relative to the ipsilateral acetabulum and the contralateral normal hip.

FIGURE 32.23 Femoral varus derotational osteotomy and acetabular shelf procedure. (A) Anteroposterior radiograph of the left hip demonstrates a bone allograft attached with two metallic screws in the superior lateral aspect of a dysplastic left acetabulum (arrow), providing good coverage of the femoral head (arrowhead). Note the hardware of the varus derotational osteotomy in the proximal left femur. (B) Coronal T2-weighted MRI of the same patient demonstrates the artifact due to the screws used for the shelf operation (long arrow). The humeral head is still separated from the acetabulum (short arrow) due to the presence of infolded labrum (arrowhead). Compare with the right side for the normal position of the femoral head within the acetabulum.

FIGURE 32.24 Salter osteotomy. (A) Anteroposterior radiograph of the pelvis in a 7-year-old girl with CDH shows persistent superolateral subluxation of the left hip following conservative treatment. Note the anterolateral orientation of the acetabulum in comparison with the normal right hip. (B) Postoperative film after Salter osteotomy through the supraacetabular portion of the iliac bone shows the acetabulum displaced anterolaterally and downward; a triangular bone graft, taken from the anterolateral aspect of the ilium, is secured by two Steinmann pins at the site of the osteotomy. (C) Four years later, the femoral head is completely covered by the acetabulum. Because of a valgus configuration of the femoral neck, the patient may yet require a varus derotational osteotomy.

Proximal Femoral Focal Deficiency

Proximal femoral focal deficiency (PFFD) is a congenital anomaly characterized by dysgenesis and hypoplasia of variable segments of the proximal femur. The defect ranges in severity from femoral shortening associated with a varus deformity of the neck to the formation of only a small stub of distal femur.

Classification and Radiographic Evaluation

Several classifications of PFFD have been proposed. The one offered by Levinson and colleagues, which is based on the severity of the abnormalities involving the femoral head, femoral segment, and acetabulum, is the most practical from the prognostic point of view:

Type A: The femoral head is present, and the femoral segment is short. There is a varus deformity of the femoral neck. The acetabulum is normal.

Type B: The femoral head is present, but there is an absence of bony connection between it and the short femoral segment. The acetabulum exhibits dysplastic changes.

Type C: The femoral head is absent or represented only by an ossicle. The femoral segment is short and tapered proximally. The acetabulum is severely dysplastic.

Type D: The femoral head and acetabulum are absent. The femoral segment is rudimentary, and the obturator foramen is enlarged.

FIGURE 32.25 Proximal femoral focal deficiency. (A) Anteroposterior radiograph in an 18-month-old boy who had a short right leg demonstrates a varus configuration at the right hip joint, the absence of an ossification center for the proximal femoral epiphysis, and shortening of the femur—the classic radiographic features of PFFD. (B) A coned-down view of the right hip shows superior, posterior, and lateral displacement of the proximal femoral segment in relation to the acetabulum. (C) Arthrography was performed to classify the abnormality, and the presence of the femoral head in the acetabulum and the absence of any defect in the femoral neck were found, making this a type A focal deficiency.

Conventional radiography is usually sufficient to make a diagnosis of PFFD. The femur is short, and the proximal segment is displaced superior, posterior, and lateral to the iliac crest; ossification of the femoral epiphysis is invariably delayed (Fig. 32.25). Arthrography is useful in the evaluation of this anomaly, particularly in its classification, because early in infancy, the nonossified femoral head and acetabulum can be outlined adequately with a positive contrast agent (Fig. 32.25C). This technique is also helpful in distinguishing PFFD from the occasionally similar presentations of CDH. In severe cases of PFFD, MRI may be useful to establish the presence or absence of cartilaginous bridge between the proximal and distal femoral segments (Fig. 32.26).

Treatment

Several surgical procedures are used to correct this anomaly, including amputation. One limb-sparing procedure involves conversion of the knee to a hip joint by flexing it 90 degrees and fusing the femur to the pelvis. Another technique, developed by Borggreve in 1930 and called the turn-about procedure or rotation-plasty after an improvement by Van Nes, converts the foot into the knee joint; the limb is then fitted with a leg prosthesis.

FIGURE 32.26 MRI of proximal focal femoral deficiency. Coronal T1-weighted image of a young girl with PFFD demonstrates absent proximal right femoral shaft terminating in a blunted chondral surface (arrow), which was not bridging with the hypoplastic proximal femoral head and neck (not shown).

Legg-Calvé-Perthes Disease

Legg-Calvé-Perthes disease, also known as coxa plana, is the name applied to osteonecrosis (ischemic necrosis) of the proximal epiphysis of the femur. Recent genetic studies suggest that beta fibrinogen gene G-455-A polymorphism is a risk factor for this condition. The anomaly occurs five times more often in boys than in girls, usually between the ages of 4 and 8 years. Its appearance at an early age is usually associated with a better prognosis. Either hip can be affected, and bilateral involvement, which is successive rather than simultaneous, is seen in approximately 10% of cases (see Fig. 32.27). The clinical symptoms consist of pain, limping, and limitation of motion. Not infrequently, the pain is localized not to the involved hip but to the ipsilateral knee. It is a self-limiting disorder that eventually heals, but because of the progressive deformity it produces in the shape of the femoral head and neck, it often leads to precocious osteoarthritis of the hip joint. The cause of this anomaly has been the subject of debate. Some investigators consider it a type of idiopathic osteonecrosis, but trauma or repeated microtrauma may play a role in compromising the circulation of blood to the femoral capital epiphysis. Trueta has suggested that the blood supply to the femoral head is deficient between the ages of 4 and 8 years and that this might be a factor in the development of the condition.

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