Kyphosis

The diagnosis of a congenital spine problem is usually made by a pediatrician before the patient is seen by an

orthopaedist. The deformity may be detected before birth on prenatal ultrasonography (46)
or noted as a clinical deformity in the newborn. If the deformity is
mild, congenital kyphosis can be overlooked until a rapid growth spurt
makes the condition more obvious. Some mild deformities are found by
chance on radiographs that are obtained for other reasons. Clinical
deformities seen in the newborn tend to have a worse prognosis than
those discovered as incidental findings on plain radiographs. Physical
examination usually reveals a kyphotic deformity at the thoracolumbar
junction or in the lower thoracic spine. An attempt should be made to
determine the rigidity of the deformity by flexion and extension of the
spine. A detailed neurologic examination should be done, looking for
any subtle signs of neurologic compromise. Associated musculoskeletal
and nonmusculoskeletal anomalies should be sought on physical
examination.

High-quality, detailed anteroposterior and lateral
radiographs provide the most information in the evaluation of
congenital kyphosis (Fig. 20.8). Failure of
segmentation and the true extent of failure of formation may be
difficult to detect on early films because of incomplete ossification.
Flexion and extension lateral radiographs are helpful in determining
the rigidity of the kyphosis and possible instability of the spine.
Computerized tomography (CT) with three-dimensional reconstructions can
identify the amount of vertebral body involvement and can determine
whether more kyphosis or scoliosis might be expected (Fig. 20.9).
CT scans can only identify the nature of the bony deformity and the
size of the cartilage anlage. They do not show the amount of growth
potential in the cartilage anlage, and therefore only an estimate of
possible progression can be made. MRI should be obtained in most cases
because of the significant incidence of intraspinal abnormalities. In
addition, the location of the spinal cord and any areas of spinal cord
compression caused by the kyphosis can be seen on MRI. The cartilage
anlage will be well defined by MRI in patients with failure of
formation (Fig. 20.10); however, as with CT
scans and plain radiographs, MRI cannot reveal how much growth
potential is present in the cartilage anlage, and can only help one to
estimate the probability of a progressive deformity.

Congenital kyphosis, as well as associated renal
problems, can be seen on routine prenatal ultrasonography at as early
as 20 weeks of gestation (46). Myelograms have
been used for documenting spinal cord compression but have been mostly
replaced by MRI. If myelography is used, images should be taken in the
prone and supine positions. Myelograms obtained in only the prone
position may miss information about spinal cord compression because of
pooling of dye around the apex of the deformity. Myelography can be
used in conjunction with CT scanning to add to the diagnostic
information obtained.

Because the natural history of this condition is usually
one of continued progression with an increased risk of neurologic
compromise, surgery is usually the preferred method of treatment (23).
If the deformity is mild or if the diagnosis is uncertain, close
observation may be a treatment option. However, observation of a
congenital kyphotic deformity must be used with caution, and the
physician must not be lulled into a false sense of security if the
deformity progresses only 3 to 5 degrees over a 6-month period. If the
deformity is observed over 2 to 3 years, it will have progressed 20 to
30 degrees and cannot thereafter be easily corrected. Bracing has no
role in the treatment of congenital kyphosis, unless compensatory
curves are being treated above or below the congenital kyphosis (23,44,47).
Bracing a rigid structural deformity, such as congenital kyphosis,
neither corrects the deformity nor stops the progression of kyphosis.
To document that there has been a significant change in kyphosis, the
radiographs should be taken by a standardized method, and the same end
vertebral bodies should be measured. This will ensure that any change
that has occurred since the previous radiograph is accurately measured.

Surgery is the recommended treatment for congenital kyphosis. The type of surgery depends on the type and size

of the deformity, the age of the patient, and the presence of
neurologic deficits. Procedures can include posterior fusion, anterior
fusion, both anterior and posterior fusions, and anterior osteotomy
with posterior fusion. Fusion can be performed with or without
instrumentation.

Some of the more frequent complications of treatment of
congenital kyphosis are pseudarthrosis, progression of kyphosis, and
paralysis. Pseudarthrosis and progression of the kyphotic deformity can
be minimized by performing anterior and posterior fusions for
deformities of more than 50 degrees. The posterior fusion should extend
from one level above to one level below the involved vertebrae. This
may allow for some correction with growth.

Paralysis is perhaps the most feared complication of
spinal surgery. The risk of this complication can be lessened by not
attempting to maximally correct the deformity with instrumentation.
Instrumentation should be used only for stabilization of rigid
deformities. The use of halo traction in rigid congenital kyphotic
deformities has been associated with an increased risk of neurologic
compromise (51). Another long-term problem,
occurring in approximately 38% of patients with kyphosis, is low back
pain caused by increased lumbar lordosis, which is needed to compensate
for the kyphotic deformity (53).

Scheuermann disease can be divided into two distinct
groups: a typical form and an atypical form. These two types are
determined by the location and natural history of the kyphosis,
including symptoms occurring during adolescence and after growth is
completed. Typical Scheuermann disease usually involves the thoracic
spine, with a well-established natural history during adolescence and
after skeletal maturity (74). This classic form of Scheuermann kyphosis will have three or more consecutive vertebrae,

each wedged 5 degrees or more (Sorensen criteria), producing a
structural kyphosis. In contrast, atypical Scheuermann disease is
usually located in the thoracolumbar junction or in the lumbar spine,
and its natural history is well defined. The atypical type is
characterized by vertebral end-plate changes, disc space narrowing, and
anterior Schmorl nodes, but does not necessarily fulfill Sorensen’s
criteria of three consecutively wedged vertebrae of 5 degrees. Thoracic
Scheuermann is the most common form, with the atypical form less
frequently seen.

Typical Scheuermann disease consists of a rigid thoracic
kyphosis in a juvenile or adolescent spine. The apex of kyphosis is
located between T7 and T9 (10). The reported incidence of Scheuermann deformities in the general population ranges from 0.4% to 10% (75,76,77,78,79). Reported male-to-female ratios vary in the literature. Scheuermann originally reported a male preponderance of 88% (72). Most reports in the literature note either a slight male preponderance or an equal male-to-female ratio (35,77,78,79,80,81,82). Bradford et al. (76) has been the only one to report an increased incidence of Scheuermann disease in women.

The age at onset of Scheuermann kyphosis is during the prepubertal growth spurt, between 10 and 12 years of age. Sorensen (78)
described a Scheuermann prodrome in patients who had a lax, asthenic
posture from the age of approximately 4 to 8 years, and in whom, within
a few years, a fixed kyphosis developed. The clinical detection of
Scheuermann disease occurs at approximately 10 to 12 years of age.
Wedging of apical vertebrae has not been reported before 10 years of
age (83). Radiographic evidence of Scheuermann
disease is usually not detectable in patients younger than 10 years of
age because the ring apophysis is not yet ossified. Until the ring
apophysis ossifies, vertebral body wedging and irregularity of the end
plate are difficult to measure on radiographs.

Many possible etiologies have been suggested for
Scheuermann disease, but the true cause remains unknown. Genetic,
vascular, hormonal, metabolic, and mechanical factors have been
suggested as causes of Scheuermann kyphosis. Sorensen (78) noted a high familial predilection, and Halal et al. (84), in a study of five families, and McKenzie and Sillence (85),
in a study of 12 families, suggested that the disease may be inherited
in an autosomal dominant fashion with a high degree of penetrance.
Additional support for a genetic basis for this condition is provided
by Carr et al. (86,87) in a report of Scheuermann disease occurring in identical twins. Halal et al. (84), McKenzie and Sillence (85), and Carr et al. (87) have reported possible autosomal dominant inheritance of Scheuermann kyphosis.

Scheuermann believed that the kyphosis was caused by a
form of avascular necrosis of the ring apophysis, which led to a growth
disturbance resulting in a progressive kyphosis with growth (72,73).
The problem with this theory is that the ring apophysis contributes
little, if at all, to the longitudinal growth of the vertebrae (87,88). Bick and Copel (89)
demonstrated that the ring apophysis lies outside the true
cartilaginous physis and contributes nothing to the longitudinal growth
of the vertebral body. Therefore, a disturbance in the ring apophysis
should not affect growth of the vertebrae or cause vertebral wedging.

Schmorl (90) described a herniation of disc material through the cartilaginous end plate, known as Schmorl nodes.
He believed that the herniation of disc material occurred because of a
weakened end plate. The disc herniation was thought to damage the
anterior end plate, resulting in abnormal growth, which in turn caused
the kyphosis. There is a definite increased incidence of Schmorl nodes
in patients with Scheuermann kyphosis, but the problem with this theory
is that Schmorl nodes are found outside the area of kyphosis, and are
also present in individuals who have asymptomatic, normal spines and do
not have a kyphotic deformity.

Ferguson (91) suggested that
persistence of an anterior vascular groove altered the anterior growth
of the vertebral body, but Aufdermaur and Spycher (92,93) and Ippolito and Ponseti (94)
were unable to document growth disturbances around the anterior
vascular groove, and concluded that persistence of an anterior vascular
groove is a sign of immaturity of the spine. Lambrinudi (95)
postulated that Scheuermann disease resulted from upright posture and a
tight anterior longitudinal ligament. The fact that no cases of
Scheuermann disease have been found in quadruped animals lends support
to this theory (96). This has led to the more
popular belief that the anterior end-plate changes are caused by
mechanical forces in response to Wolff’s law or the Hueter-Volkmann
principle. Compression forces in the anterior growth plate cause a
decrease in growth in the area of the kyphosis. Indirect support for
this argument can be found in the changes in the wedging of the
involved vertebral bodies and the reversal of these changes when
bracing or casting is used in the immature spine. Scoles et al. (96)
also support this theory by demonstrating disorganized endochondral
ossification in the involved vertebrae, similar to that seen in Blount
disease. They conclude that the changes in endochondral ossification
are the result of increased pressure on the vertebral growth plate.

Ascani et al. (97,98)
found that patients who have Scheuermann disease tend to be taller than
normal for their chronologic and skeletal ages, and that their bone age
tends to be more advanced than their chronologic age. Because they
found increased growth hormone levels in these patients, they suggested
that the increased height and the advanced skeletal age could be caused
by the increased growth hormone (97,98). The increased height and more rapid growth may make the vertebral end plates

more susceptible to increased pressure and result in the changes seen
in Scheuermann disease. The increased growth hormone levels noted by
Ascani et al. may also lead to a relative osteoporosis of the spine,
which, in turn, may predispose the spine to the development of
Scheuermann disease.

Bradford et al. (75,99), Burner et al. (100), and Lopez et al. (101)
reported in the 1980s that Scheuermann kyphosis may be caused by a form
of juvenile osteoporosis. However, using quantitative CT scans, Gilsanz
et al. (102) found no evidence of osteoporosis
in patients with Scheuermann kyphosis compared with normal research
subjects. The authors suggested that the technique used to determine
osteoporosis might account for the differences between their report and
those that show osteoporosis. In a study using single-photon
absorptiometric analysis of cadaver vertebrae from patients with
Scheuermann kyphosis, Scoles et al. (96) also found no evidence of osteoporosis.

What is shown by the histologic studies of Ascani et al. (97), Ippolito et al. (94,103), and Scoles et al. (96)
is that an alteration in endochondral ossification occurs. Whether this
altered endochondral ossification is the cause or result of kyphosis is
not known. Ippolito and Ponseti (94) found a
decrease in the number of collagen fibers, which were thinner than
normal, and an increase in proteoglycan content. Some areas of the
altered end plate showed direct bone formation from cartilage instead
of the normal growth-plate sequences for ossification. These studies
help support the belief that Scheuermann kyphosis is an underlying
growth problem of the anterior vertebral end plates.

Atypical Scheuermann kyphosis, or thoracolumbar and
lumbar kyphosis, is believed to be caused by trauma to the immature
spine, resulting in irregularities of the end plate (104).

Many early studies suggested an unfavorable natural
history for Scheuermann disease and recommended early treatment to
prevent severe deformity, pain, impaired social functioning,
embarrassment about physical appearance, myelopathy, degeneration of
the disc spaces, spondylolisthesis, and cardiopulmonary failure.
Despite these reports, few long-term follow-up studies of Scheuermann
disease were performed until that of Murray et al. (77). Findings by Travaglini and Conti (35,105), Murray et al. (77), and Lowe (106) suggest that the natural history of the disease tends to be benign.

The kyphotic deformity progresses rapidly during the adolescent growth spurt. Bradford et al. (107)
noted that, among the patients who required brace treatment, more than
half had progression of their deformities during this growth spurt
before brace treatment was begun. Little is known about progression of
the kyphosis after growth is completed, and whether it is similar to
that in scoliosis. It is not well documented whether the kyphosis will
continue to progress beyond a certain degree during adulthood.

Tragvaglini and Conte (35) found
that the kyphosis did progress during adulthood, but few patients
developed severe deformities. What is known is that patients with
Scheuermann kyphosis have more intense back pain, jobs that require
relatively little physical activity, less range of motion of the trunk
in extension, and different localization of back pain than the general
population that does not have Scheuermann kyphosis (77).
Even with these findings, when compared with normal individuals,
patients with Scheuermann kyphosis have no significant differences in
self-esteem, social limitations, or level of recreational activities.
The number of days they miss from work because of back pain is also
similar.

The data regarding the natural history of Scheuermann
disease suggest that, although patients may have some functional
limitations, their lives are not seriously restricted, and they have
few clinical or functional problems. Pulmonary function actually
increases in these patients, probably because of the increased diameter
of the chest cavity, until their kyphosis is more than 100 degrees.
Patients with kyphosis of more than 100 degrees have restrictive
pulmonary function. Another finding in patients with Scheuermann
kyphosis was that disc degeneration was five times more likely to be
seen on MRI in patients with Scheuermann compared with controls (108). The clinical significance of this finding is not known (77).

Mild to moderate scoliosis is present in about one third of patients with Scheuermann disease (106),
but the curves tend to be small, approximately 10 to 20 degrees.
Scoliosis associated with Scheuermann disease usually has a benign
natural history. The scoliotic curve is rarely progressive, and usually
does not require treatment. Deacon et al. (109,110)
divided scoliotic curves found in patients with Scheuermann disease
into two types, based on the location of the curve and the rotation of
the vertebrae into or away from the concavity of the scoliotic curve.
In the first type of curves, the apices of scoliosis and kyphosis are
the same, and the curve is rotated toward the convexity. The rotation
of the scoliotic curve is opposite to that normally seen in idiopathic
scoliosis. Deacon et al. (109,110)
suggested that the difference in direction of rotation is caused by
scoliosis occurring in a kyphotic spine, instead of the hypokyphotic or
lordotic spine that is common in idiopathic scoliosis. In the second
type of curves, the apex of the scoliosis is above or below the apex of
the kyphosis, and the scoliotic curve is rotated into the concavity of
the scoliosis, more like idiopathic scoliosis. This type of scoliosis
seen with Scheuermann kyphosis is the more common, and it rarely
progresses or requires treatment.

Lumbar spondylolysis is a frequently associated finding in Scheuermann kyphosis (Fig. 20.14).
The suggested reason for the increased incidence of spondylolysis is
that increased stress is placed on the pars interarticularis because of
the associated compensatory hyperlordosis of

the
lumbar spine in Scheuermann disease. This increased stress causes a
fatigue fracture at the pars interarticularis, resulting in
spondylolysis. Ogilvie and Sherman (111)
found a 50% incidence of spondylolysis in the 18 patients they
reviewed. Stoddard and Osborn reported a 54% incidence of spondylolysis
in their patients with Scheuermann kyphosis (112).

Other conditions reported in patients with Scheuermann disease include endocrine abnormalities (113), hypovitaminosis (114), inflammatory disorders (112,113), and dural cysts (96,115).

Clinical signs of Scheuermann disease occur around the
time of puberty. The clinical feature that distinguishes postural
kyphosis from Scheuermann kyphosis is rigidity. Often, mild Scheuermann
disease is believed to be postural because the kyphosis may be more
flexible in the early stages than in later stages. Usually, the patient
seeks treatment because of a parent’s concern about poor posture.
Sometimes the poor posture has been present for several months or
longer, or the parents may have noticed a recent change during a growth
spurt. Attributing kyphotic deformity in a child to poor posture often
causes a delay in diagnosis and treatment.

Pain may be the predominant clinical complaint rather
than deformity. The pain is generally located over the area of the
kyphotic deformity, but also occurs in the lower lumbar spine if
compensatory lumbar lordosis is severe. Back pain is usually aggravated
by standing, sitting, or physical activity. The distribution and
intensity of the pain vary according to the age of the patient, the
stage of the disease, the site of the kyphosis, and the severity of the
deformity. Pain usually subsides with the cessation of growth, although
pain in the thoracic spine can sometimes continue even after the
patient is skeletally mature (77,116).
More commonly, after growth is completed patients complain of low back
pain caused by the compensatory or exaggerated lumbar lordosis.

Most symptoms relating to Scheuermann disease occur
during the rapid growth phase. During the growth spurt, pain is
reported by 22% of patients, but as the end of the adolescent growth
spurt approaches, this figure reaches 60%. Some authors believe that
when growth is complete the pain recedes completely, except for
well-circumscribed paraspinal discomfort (117,118,119). In adult patients with Scheuermann disease, pain may be located in and around

the posterior iliac crest. This pain is thought to result from
arthritic changes at T11 and T12, because the posterior crest is
supplied by this dermatome. Stagnara (120) believes that the mobile areas above and below the rigid segment are the source of pain.

Symptoms also depend on the apex of kyphosis. Murray et al. (77)
noted that if the apex of kyphosis is in the upper thoracic spine,
patients have more pain with everyday activities. The degree of
kyphosis has also been correlated with symptoms. It seems logical that
the larger the kyphosis, the more likely it is to be symptomatic, but
Murray et al. (77) found that curves between 65
and 85 degrees produced the most symptoms, whereas curves of more than
85 degrees and less than 65 degrees produced fewer symptoms. However,
in patients with thoracolumbar or lumbar kyphosis (atypical Scheuermann
disease), activity decreased as the degree of kyphosis increased.

In a patient with Scheuermann disease, a thorough
examination of the back and a complete neurologic evaluation are
essential. With the patient standing, the shoulders appear to be
rounded and the head protrudes forward. The anterior bowing of the
shoulders is caused by tight pectoralis muscles. Angular kyphosis is
seen most clearly when the patient is viewed from a lateral position
and is asked to bend forward. Normally, the back exhibits a gradual
rounding with forward bending, but in patients with Scheuermann disease
an acute increase is evident in the kyphosis of the thoracic spine or
at the thoracolumbar junction. Stagnara et al. (122)
found cutaneous pigmentation to be common at the most protruding
spinous process at the apex of the kyphosis, probably the result of
friction exerted by the backs of chairs and clothing. Compensatory
lumbar and cervical lordosis, with forward protrusion of the head,
further increases the anterior flexion of the trunk. Associated
hamstring and hip flexor muscle tightness are often present.

The kyphotic deformity has some rigidity and will not
correct completely with hyperextension. Larger degrees of kyphosis are
not necessarily more rigid, and the amount of rigidity will vary with
the age of the patient (77).

The neurologic evaluation is usually normal but must not
be overlooked. Spinal cord compression has been reported occasionally
in patients with Scheuermann disease (123,124,125,126,127). Three types of neural compression have been reported: ruptured thoracic disc (128),
intraspinal extradural cyst, and mechanical cord compression at the
apex of kyphosis. However, spinal cord compression and neurologic
compromise are rare (129). Bouchez et al. (70) found that only 1% of patients with a paralyzing disc herniation had Scheuermann disease. Ryan and Taylor (126)
suggest that the factors influencing the onset of cord compression in
patients whose cord compression is caused by the kyphosis alone are the
angle of kyphosis, the number of segments involved, and the rate of
change of the angle of kyphosis. This may be why neurologic findings
are rare in Scheuermann kyphosis: the kyphosis occurs gradually, over
several segments, and without acute angulation.

The most important radiographic views are
anteroposterior and lateral views of the spine with the patient
standing. The amount of kyphosis present is determined by the Cobb
method on a lateral radiograph of the spine. This is accomplished by
selecting the cranial- and caudal-most tilted vertebrae in the kyphotic
deformity. A line is drawn along the superior end plate of the most
cranial vertebra and the inferior end plate of the most caudal
vertebra. Lines are drawn perpendicular to the lines along the end
plates, and the angle they form where they meet is the degree of
kyphosis (130).

The criterion for diagnosis of Scheuermann disease on a
lateral radiograph is more than 5 degrees of wedging of at least three
adjacent vertebrae (78). The degree of wedging
is determined by drawing one line parallel to the superior end plate
and another line parallel to the inferior end plate of the vertebra,
and measuring the angle formed by their intersection. Bradford believes
that three wedged vertebrae are not necessary for the diagnosis, but
rather an abnormal, rigid kyphosis is indicative of Scheuermann disease
(131).

The vertebral end plates are irregular, and the disc
spaces are narrowed. The anteroposterior diameter of the apical
vertebra is frequently increased (96) (Fig. 20.15).
Associated Schmorl nodes are often seen in the vertebrae in the
kyphosis. Flexibility is determined by taking a lateral radiograph with
the patient lying over a bolster placed at the apex of the deformity,
to hyperextend the spine and maximize the amount of correction seen on
a hyperextension radiograph. On the lateral radiographs, most patients
will be in negative sagittal balance (132).
Sagittal balance is measured on the radiographs by dropping a plumb
line from the center of the C7 vertebral body and measuring the
distance from this line to the sacral promontory; a positive value
indicates that the plumb line lies anterior to the promontory of the
sacrum. Normal sagittal balance values are ± 2cm to the sacral
promontory. On a lateral radiograph of lumbar Scheuermann kyphosis,
irregular

end
plates, Schmorl nodes, and disc-space narrowing will be seen, but
vertebral-body wedging is not as common. MRI and CT scans are necessary
only if the patient has unusual symptoms or positive neurologic
findings. An anteroposterior or posteroanterior radiograph of the spine
should be obtained to look for associated scoliosis or vertebral
anomalies. The patient’s skeletal maturity can be estimated from a
radiograph of the left hand and wrist, or from the Risser sign on the
anteroposterior radiograph of the spine.

The indications for the treatment of patients with
Scheuermann kyphosis can be grouped into five general categories: pain,
progression of deformity, neurologic compromise, cardiopulmonary
compromise, and cosmesis.

Treatment options include observation, nonoperative
methods, and surgery. Observation is an active form of treatment. If
the deformity is mild and nonprogressive, the kyphosis can be observed
every 4 to 6 months with lateral radiographs. The parents and patient
must understand the need for regular follow-up visits. If the deformity
begins to progress, another form of treatment, such as bracing,
casting, or surgery, may be indicated.

Nonoperative methods of treatment include exercise,
physical therapy, bracing, and casting. Exercise and physical therapy
alone will not permanently improve kyphosis that is caused by skeletal
changes. The improvement seen with these methods is due to improved
muscle tone and correction of bad posture. The goals of physical
therapy are to increase flexibility of the spine, correct lumbar
hyperlordosis, strengthen extensor muscles of the spine, and stretch
tight hamstring and pectoralis muscles. The efficacy of this treatment
method has not been proven, and although it may improve the postural
component of Scheuermann disease, its effect on a rigid kyphosis is
questionable.

Other nonoperative treatment methods can be divided into
active correction systems (braces) and passive correction systems
(casts). For either a brace or a cast to be effective, the kyphotic
curve must be flexible enough to allow correction of at least 40% to
50% (83,98,133).

The Milwaukee brace is the brace recommended for the treatment of Scheuermann disease (134) (Fig. 20.16). The

Milwaukee brace functions as a dynamic three-point orthosis that
promotes extension of the thoracic spine. The neck ring maintains
proper alignment of the upper thoracic spine, and the padded poster
uprights apply pressure over the apex of the kyphosis. The pelvic
girdle stabilizes the lumbar spine by flattening the lumbar lordosis. A
low-profile brace, without a chin ring and with anterior shoulder pads,
can be used for curves with an apex at the level of T9 or lower. The
indications for brace treatment are an immature spine (at least 1 year
of growth remaining in spine), some flexibility of the curve, and
kyphosis of more than 50 degrees. The brace is initially worn full-time
for an average of 12 to 18 months. If the curve is stabilized and no
progression is noted after this time, a part-time brace program can be
used until skeletal maturity is reached. Gutowski and Renshaw (135)
reported that part-time bracing (16 hours per day) is as effective as
full-time bracing, and is associated with improved patient compliance.
In this study, a Boston lumbar orthosis was used to treat the kyphosis.
The rationale for correction with this orthosis is that reduction of
the lumbar lordosis causes the patient to dynamically straighten the
thoracic kyphosis to maintain an upright posture. This presupposes a
flexible thoracic kyphosis, a normal neurovestibular axis, and the
absence of hip-flexion contractures.

Several orthopaedists have noted that, after initial
improvement, there is a significant loss of correction after the
discontinuation of brace treatment (50,136). Montgomery and Erwin (82)
believe that if permanent correction of kyphosis is possible, a change
in vertebral body wedging should be seen before bracing is
discontinued. Although some loss of correction can occur after bracing
is discontinued, it is still effective in obtaining some correction of
the kyphosis, and possibly in reversing vertebral body wedging, or at
least preventing progression of the kyphotic deformity (82) (Fig. 20.17).
Poor results with brace treatment have been reported in patients in
whom the kyphosis exceeded 75 degrees; in cases when the wedging of the
vertebral bodies was more than 10 degrees; or when the patient was near
or past skeletal maturity (131).

Antigravity and localizer casts have been used
extensively in Europe for nonoperative treatment of Scheuermann
kyphosis, with good results (120,137,138,139). De Mauroy and

Stagnara (137)
developed a therapeutic regimen that uses serial casts for correction.
This method consists of three stages. First, a physical therapy program
is started in preparation for the casts. Next, three sequential
antigravity casts, changed at 45-day intervals, are applied in order to
obtain gradual correction of the deformity. The third stage involves
the use of a plastic maintenance brace that is worn until skeletal
maturity is reached. With this regimen the deformity was reported to
improve by 40%, and there was less loss of correction after this form
of nonoperative treatment was discontinued (120,138,139).

The indications for surgical correction remain unclear
because of various opinions about pain, disability, trunk deformity,
and importance of cosmesis. Therefore, the decision for surgery must be
made on an individual basis. The current indications for surgery are a
progressive kyphosis of more than 75 degrees, or significant kyphosis
associated with pain that is not alleviated by nonoperative treatment
methods. The biomechanical principles of correction of kyphosis
secondary to Scheuermann disease include lengthening the anterior
column (anterior release), providing anterior support (interbody
fusion), and shortening and stabilizing the posterior column
(compression instrumentation and arthrodesis) (140).
Surgical correction of kyphosis can be achieved by a posterior
approach, an anterior approach, or a combined anterior and posterior
approach. The combined anterior and posterior approach has been the
most frequently recommended and reliable procedure (141,142,143,144) (Fig. 20.18).
A posterior procedure alone can be considered if the kyphosis can be
corrected to, and maintained at, less than 50 degrees while a posterior
fusion occurs (136,137,138,145,146). The spine can be instrumented with Harrington compression rods (77,147) or a posterior segmental hook-and-screw type of instrumentation system (148).
If Harrington compression rods are used for posterior instrumentation,
¼-inch rods are used. Even when ¼-inch Harrington compression rods are
used, a brace or cast should be applied after surgery to prevent rod
breakage until a solid fusion is obtained. Prolonged immobilization is
necessary, however, and there are potential complications. With
posterior segmental instrumentation systems and the use of pedicle
screws, posterior-only surgery for flexible curves has become more
popular, but long-term outcome studies have yet to be published. When
this type of instrumentation system is used, postoperative
immobilization may not be required. Anterior instrumentation for
Scheuermann disease has been reported by Kostuik (149);
it consists of anterior interbody fusion and anterior instrumentation
with a Harrington distraction system augmented by postoperative
bracing. The single or dual rods and multiple bone screws that are
available in the present-day spine instrumentation systems may be used
instead of the Harrington distraction system. Although Kostuik has
reported good results with this technique, the anterior instrumentation
approach for treatment of Scheuermann kyphosis is not widely used (149).

When anterior and posterior surgery together are
performed for Scheuermann disease, the anterior release and fusion are
performed first. The anterior release can be done by an open anterior
exposure or by thoracoscopy. The posterior fusion and instrumentation
can be done on the same day as the anterior release and fusion, or they
can be done as a staged procedure. Harrington compression rods can be
used for posterior instrumentation, but usually a segmental
instrumentation system using multiple hooks or pedicle screws is used.
Lowe (143) and Coscia et al. (150)
have reported a high complication rate after using Luque rods and wires
for posterior fixation, because this system does not allow for any
compression. The posterior instrumentation should include at least
three fixation points above the apex and at least two fixation points
below the apex of the kyphosis. The fusion and instrumentation should
include the proximal vertebra in the measured kyphotic deformity and
the first lordotic disc distally (104,132,140,151).
If the fusion and instrumentation end in the kyphotic deformity, a
junctional kyphosis at the end of the instrumentation is likely to
develop.

Lowe emphasized that overcorrection of the deformity should be avoided in order to prevent junctional kyphosis (140,143).
He recommended that no more than 50% of the preoperative kyphosis be
corrected and that the final kyphosis should never be less than 40
degrees. He also found that patients with Scheuermann disease tend to
be in negative sagittal balance and become further negatively balanced
after surgery, which may predispose them to the development of
junctional kyphosis (132). Reinhardt and Bassett (152)
recommended fusion to the first square vertebra distally if the end
vertebra distally is wedged, so as to prevent junctional kyphosis. The
type of instrumentation used will determine whether postoperative
immobilization is needed. This immobilization can consist of a brace or
a Risser body cast. The patient’s activity is restricted for 6 to 9
months until a solid fusion is obtained.

The evaluation of a postlaminectomy deformity should
focus on (a) the flexibility of the deformity, (b) loss of spinal
structures, and (c) determination of future deformity with growth. The
flexibility of a deformity can be estimated by flexion and extension
lateral radiographs. If these cannot be obtained, a lateral traction
film may be used. CT scans and three-dimensional reconstruction views
may better delineate which bony elements are missing. MRI may be used
but gives more information about the spinal cord, disc, and surrounding
soft tissue than about the bony elements. To aid in preoperative
planning, Lonstein recommends drawing the spine preoperatively (153).
The lines should represent the spinous processes and intact laminae and
facet joints. This may aid in predicting progression of a
postlaminectomy deformity.

Treatment of postlaminectomy kyphosis is difficult, and it is best to prevent the deformity from occurring (175).
The facet joints should be preserved whenever possible during
laminectomy. Localized fusion at the time of facetectomy or laminectomy
may help prevent progressive deformity (176).
Because of the loss of bone mass posteriorly, however, localized fusion
may not produce a large enough fusion mass to prevent kyphosis. Even
so, this approach is advocated because it may produce enough bone mass
posteriorly to stabilize what otherwise would be a severe progressive
deformity.

The surgical technique of laminoplasty to expose the
spinal cord may lessen the chance of progressive deformity. This
approach involves suturing the laminae back in place after removal, or
removing just one side of the laminae and allowing them to hinge open
like a book to expose the spinal cord, then suturing that side of the
laminae back in place (177,178,179).
This procedure may provide only a fibrous tether connecting the laminae
to the spine, but studies have shown a decreased incidence of
postlaminectomy kyphosis when it has been used (180,181).
Another technique is to hinge the laminae open in a lateral direction
after dividing the laminae in the midline. This provides a lateral
trough for the placement of bone graft for a lateral fusion (182,183). The use of these techniques has been reported to decrease the incidence of postlaminectomy deformity (165,184).

After surgery in which the laminae have been removed, bracing has been suggested to prevent deformity (185,186),
although no studies have documented the efficacy of this form of
treatment. After the deformity has occurred and started to progress,
bracing is ineffective in preventing further progression (153,156).

For progressive or marked deformity, spinal fusion is
recommended, although the patient’s long-term prognosis should be
considered before making definitive treatment plans. If the prognosis
for survival is poor, spinal fusion may not be appropriate. However,
given the availability of effective treatment protocols for tumors and
the improved survival rates, fusion is usually indicated for
progressive deformity. Combined anterior and posterior spinal fusion is
preferred in most patients (187) because the frequency of pseudarthrosis is greater if either procedure is done alone.

Lonstein (153) reported
pseudarthrosis in 57% of patients after posterior fusion and in 15% of
patients after anterior fusion. Anterior and posterior fusion can be
performed on the same day, or as staged procedures. When the anterior
procedure is performed, care must be taken to remove all the physes
back to the posterior longitudinal ligament. Leaving some of the physes
in the vertebral body can cause an increase in the deformity. When the
posterior procedure is performed, instrumentation of the involved spine
is desirable, but not always possible, because of the absence of
posterior elements. The development of pedicle screw fixation has been
helpful in allowing the use of posterior instrumentation for
postlaminectomy kyphosis. When it can be performed safely, this
procedure provides secure fixation while the spinal fusion is maturing.
Torpey et al. (188) recommend a posterior
fusion using titanium rod instrumentation at the time of laminectomy.
The instrumentation provides stability postoperatively, and the
titanium rods allow for postoperative MRI to evaluate spinal cord
tumors. In certain cases, anterior instrumentation with rod and bone
screws or plates may be used in order to obtain stability and
correction of the deformity (188). If the
deformity is severe or long-standing, anterior release followed by halo
traction, or a halo cast with an Ilizarov device, can be used for
obtaining gradual correction (189,190).

Milwaukee brace treatment has been recommended for
progressive curves, but generally has been ineffective for
postirradiation kyphosis (204,216),
especially in patients with soft tissue contractures contributing to
the deformity. The irradiated skin may also be of poor quality, making
long-term brace wear difficult. If progression occurs, spinal fusion,
with or without instrumentation, should be performed

regardless
of the age of the patient. Because bone quality is poor, fusion can be
difficult to obtain after a single attempt. Anterior and posterior
fusion are recommended, and should extend at least one or two levels
above and below the end of the kyphosis (168,188,204,216,217,218).
The posterior fusion mass may require reexploration and repeated bone
grafting after 6 months, and immobilization may need to be prolonged
for 6 to 12 months. Posterior instrumentation should be used whenever
feasible, because it adds increased stability while the fusion mass is
maturing and may allow for some limited correction of the kyphotic
deformity (Fig. 20.21). Anterior
instrumentation can be used in certain cases. However, because of the
radiation, the vertebral bodies usually remain in an infantile form,
and instrumentation with bone screws may be difficult.

Correction of postirradiation kyphosis is difficult.
Typically, these curves are rigid, and soft tissue scarring and
contractures often further hamper correction. Healing can be prolonged,
and pseudarthrosis is common. Infection is a frequent complication in
these patients because of poor vascularity of the irradiated tissue (204). Riseborough et al. (204) reported a pseudarthrosis rate of 37% and an infection rate of 23% in his patients after surgery. King and Stowe (216)
also reported a high complication rate in patients who were treated
surgically. Because viscera also can be damaged by irradiation, bowel
obstruction, perforation, and fistula formation may occur after spinal
fusion. This can be difficult to differentiate from postoperative cast
syndrome, and the treating physician should be aware of this
complication (219). Radiation myelopathy may also occur in this patient population (220). King and Stowe (216)
reported postoperative paraplegia in 2 of 7 patients who had undergone
radiation treatment for neuroblastoma and surgery for correction of
their kyphotic spine deformity. King and Stowe believed that these two
patients had a subclinical form of radiation myelopathy and that spinal
correction compromised what little vascular supply there was to the
cord. Therefore, the surgeon should be aware of this possibility and
try to avoid overcorrection.

Treatment of spinal problems is required most often in
patients with achondroplasia. The most common sagittal plane deformity
in achondroplastic dwarfs is thoracolumbar kyphosis (223,224,225).
The kyphosis is usually detected at birth, and is accentuated when the
child is sitting because of the associated hypotonia in these infants (226).
Ambulation is delayed until approximately 18 months of age, but after
ambulation begins, the thoracolumbar kyphosis tends to improve. The
kyphosis usually does not resolve in children who have more hypotonia.
According to Lonstein (227), thoracolumbar
kyphosis resolves in 70% of achondroplastic dwarfs, and persists in
30%. In one third of these patients, or 10% of achondroplastic dwarfs,
the thoracolumbar kyphosis is progressive (227) (Fig. 20.22).

A lateral radiograph of the thoracolumbar spine during
infancy shows anterior wedging of the vertebrae at the apex of the
kyphosis (225). In patients whose thoracolumbar
kyphosis resolves, the anterior vertebral body wedging also improves.
When the kyphosis is progressive, anterior vertebral body wedging
persists.

Sponseller has reported three reasons why thoracolumbar
kyphosis should be corrected: (a) it may cause pressure on the conus
and result in neurologic symptoms; (b) it results in an increase in the
compensatory lumbar lordosis, which can increase problems from an
already stenotic lumbar spine; (c) it may increase significantly if
decompressive laminectomies are needed for lumbar stenosis in the
future (226).

If no improvement in the thoracolumbar kyphosis is
evident once a child begins walking, a thoracolumbosacral orthosis
(TLSO) is recommended in order to try to prevent progression of the
kyphosis (228,229,230,231). Early treatment to prevent the development of a progressive kyphosis has been recommended by Pauli et al. (232).
They developed an algorithm for treatment of the young achondroplastic
patient, first counseling the parents against unsupported sitting and
continuing with close follow-up. If kyphosis develops and is greater
than 30 degrees, TLSO bracing is begun and continued until the child is
walking independently and there is evidence of improvement in vertebral
body wedging and kyphosis. Using this form of early intervention, Pauli
et al. (232) reported no occurrences of
progressive kyphosis. Sponseller recommends serial hyperextension
casting if the kyphosis does not respond to bracing. If there is a
satisfactory response to serial casting (50% or more correction in 3 to
4 months), brace treatment can be resumed (226).

Indications for surgery are documented progression of a
kyphotic deformity, kyphosis of more than 40 degrees in a child older
than 5 or 6 years of age, and neurologic deficits relating to the
spinal deformity (224,226,233).
Distinguishing between neurologic deficits that result from a kyphotic
deformity and those associated with lumbar stenosis (which is common in
achondroplastic dwarfs) can

be
difficult. A thorough physical examination and diagnostic studies such
as CT scan and MRI may be necessary in order to determine appropriate
treatment. The infant should be evaluated for foramen magnum stenosis,
because this may be the underlying cause for the hypotonia and delayed
ambulation in achondroplastic patients with kyphosis. If present, the
stenosis should be treated by decompression of the foramen magnum (234).
Most patients with progressive thoracolumbar kyphosis require combined
anterior and posterior fusion. Instrumentation that uses hooks or wires
that go into the spinal canal is not recommended in these patients
because the small size of the spinal canal and the lack of epidural fat
make instrumentation hazardous. Ain has reported good results with
anterior fusion and instrumentation combined with posterior fusion.
This has the advantage of not entering an already stenotic spinal canal
and giving secure fixation to aid in spinal fusion (235).

Kyphotic deformities can also occur in children with
pseudoachondroplasia and are caused by wedging of multiple vertebral
bodies in the thoracolumbar and thoracic spine. The kyphotic deformity
in patients with pseudoachondroplasia differs from that in patients
with achondroplasia. In patients with pseudoachondroplasia, the
kyphosis involves multiple levels, and is less acutely angular than the
deformity in patients with achondroplasia, which involves only one or
two levels. Bracing may prevent progression of this deformity, but
surgery is indicated if progression occurs despite bracing. Spinal
fusion with instrumentation can be performed safely in patients with
pseudoachondroplasia because there is no associated stenosis of the
spinal canal as in patients with achondroplasia (236,237).

Thoracolumbar kyphotic deformities occur in
approximately half of the patients with congenital spondyloepiphyseal
dysplasia; these deformities usually respond to a modified TLSO (226). If surgery is needed for a progressive kyphosis, anterior and posterior fusions are recommended (237).

Spinal deformity is a common finding in diastrophic dysplasia (238).
These spinal deformities consist of cervical kyphosis, thoracic
kyphoscoliosis, and lumbar hyperlordosis. Midcervical kyphosis occurs
in 15% to 33% of patients with diastrophic dwarfism (226,239,240). However, Remes et al. and Herring have reported spontaneous improvement (239,240,241). Progressive cervical kyphosis (>60 degrees) can be stabilized with a spinal fusion (210,220,221).
If a posterior fusion is to be performed, the increased incidence of
cervical spina bifida in diastrophic dwarfism must be considered during
dissection (239,240,242).

Mucopolysaccharidoses are inherited lysosomal storage
disorders caused by deficiency of the enzymes that are necessary for
the degradation of glycosaminoglycans. There are at least 13 types of
mucopolysaccharidoses. The more common names of this condition are
Hurler, Hunter, Sanfilippo, Morquio, and Moroteux-Lamy syndromes. Bone
marrow transplantation has increased the life expectancy of these
patients. Before this treatment method became available, most children
did not survive long enough to require intervention for spinal
deformities. With increased survival, progressive kyphotic deformities
of the spine with neurologic compromise are being reported (243,244,245).
Despite bone marrow transplantation, the deposition of metabolites in
bone is not reversed to the same extent as that in soft tissue (246).

Children with mucopolysaccharidosis develop
thoracolumbar kyphosis, with anterior beaking and flattening of the
vertebral bodies at the level of the kyphotic deformity. Swischuk
suggested a mechanical cause for the anterior beaking (247).
He postulated that hypotonia results in thoracolumbar kyphosis,
resulting in herniation of the nucleus pulposus into the anterior
vertebral body, which causes the anterior beaking of the vertebral
body. Field, however, examined two specimens at postmortem and found
that the end-plate formation was normal, but there was a failure of
ossification in the anterosuperior part of the vertebral body (246).

Bracing may be used in order to prevent progression of
the kyphotic deformity, but the effectiveness of this form of treatment
has not been documented. Spinal fusion is recommended for a progressive
kyphosis in patients with mucopolysaccharidosis. Tandon reported good
results with posterior spinal fusion, and Dalvie has reported good
results with anterior fusion and instrumentation (243,244).
Further studies will be needed to determine which approach is best, but
the goal of surgery is to obtain a stable fusion of the involved area
to prevent any further progression of the kyphosis (226,237,248).

Gaucher disease is an uncommon hereditary glycolipid
storage disorder characterized by the accumulation of glucocerebroside
in the lysosomes of macrophages of the reticuloendothelial system.
Splenomegaly with associated pancytopenia is the most common clinical
manifestation. The skeletal manifestations are caused by infiltration
of the bone marrow by Gaucher cells; they include bone crisis,
pathologic fracture, osteopenia, osteonecrosis, and osteomyelitis.
Progressive kyphosis of the spine has been reported in these patients.
The proposed etiology of the

kyphosis
is infiltration of the bone marrow by Gaucher cells, resulting in bone
crisis, osteopenia, and osteonecrosis that lead to vertebral body
collapse, often on multiple levels. Kyphosis can be progressive because
of continued vertebral body collapse or growth abnormalities secondary
to vertebral body collapse. If a progressive kyphosis develops,
surgical intervention is recommended. If the spine is still flexible,
posterior fusion and instrumentation are adequate, but if the deformity
is rigid, anterior and posterior fusion and instrumentation are needed (Fig. 20.23) (249,250).

Marfan syndrome is a generalized disorder of connective
tissue that affects the supporting structures of the body, especially
those in the musculoskeletal system. This syndrome is caused by
mutations in coding of the genes for the glycoprotein fibrillin (251,252).
Spinal deformity is the most common skeletal abnormality in Marfan
syndrome, and scoliosis is the most common of these spinal deformities (227,253,254,255,256,257,258). Thoracic lordosis has been traditionally reported as the most common sagittal plane deformity (259,260).
In some patients, the thoracic lordosis becomes severe enough to
compromise respiration. With the lordotic posture of the thoracic
spine, an associated kyphosis or relative kyphosis may develop in the
lumbar spine. A third common spinal deformity associated with Marfan
syndrome is thoracolumbar kyphosis, which affects approximately 10% of
patients (Fig. 20.24). These spinal deformities usually occur during the juvenile growth period, before the adolescent growth spurt (260).
Sponseller et al. found that 41% of their patients with Marfan syndrome
had a kyphotic deformity of more than 50 degrees, with a tendency
toward longer kyphoses extending through the thoracolumbar junction (261).

Brace treatment has been recommended to try to halt the progression of spinal deformity but has been found to be ineffective (262,263). Correction of kyphotic deformities requires anterior and posterior spinal fusion with segmental instrumentation (262).
Thoracic lordosis is corrected by posterior segmental instrumentation
to correct the lordotic deformity, followed by posterior fusion (264).
Because dural ectasia corrodes pedicles, a CT scan of the pedicles
should be obtained to plan fixation. In addition, fusion should be
extended. Complications are more frequent after surgical correction of
spinal deformity in patients with Marfan syndrome than after spinal
surgery in other patients (262).

Cervical spine abnormalities are also common in patients with Marfan syndrome, but clinical problems from these

abnormalities are rare. Basilar impression and focal cervical kyphosis
are the most frequently reported cervical spine abnormalities. Focal
cervical kyphosis is usually associated with a lordotic thoracic spine (265).

Because of the increased incidence of cervical spine abnormalities, Hobbs et al. (265)
have recommended that patients with Marfan syndrome should avoid sports
that involve risks of high-impact loading of the cervical spine.

In 1950, Larsen et al. (266) described a congenital malformation syndrome (267)
consisting of facial dysmorphism and hyperelasticity of the joints,
with congenital dislocation of the knees and frequent dislocation of
the hips and elbows (119,268,269,270,271).
Equinovarus or valgus foot deformities and ancillary calcaneal nuclei
are also characteristic features of this syndrome. Abnormalities of the
cervical spine, specifically cervical kyphosis, were not emphasized in
the original description, and often this life-threatening finding is
overlooked (189,268,272). Johnston et al. (267)
reported cervical kyphosis and vertebral body anomalies in five of nine
patients with Larsen syndrome. The apex of the kyphosis usually occurs
at the fourth or fifth cervical vertebra, with marked hypoplasia of one
or two of the vertebral bodies (Fig. 20.25).
Cervical kyphosis is present in infants with Larsen syndrome.
Developmental delay may be attributed to hypotonia and dislocation of
the knees or hips, but the underlying cause for developmental delay may
be a chronic myelopathy from the cervical kyphosis. Cervical kyphosis
and vertebral hypoplasia are easily demonstrated on lateral C-spine
radiographs. Flexion and extension views are usually not needed and may
be difficult to obtain safely in an infant. MRI scans will demonstrate
spinal cord compression or compromise.

The treatment recommendation for cervical kyphosis in
Larsen syndrome is the use of an early posterior arthrodesis to
stabilize the spine. An in situ posterior
arthrodesis with autogenous iliac crest bone graft, followed by
immobilization in either a halo or Minerva cast or custom orthosis, is
recommended. Reduction of the kyphosis is obtained only in the
postoperative halo or Minerva cast or orthosis stage of the treatment.
Johnston et al. (267) found that, over a period
of time following a solid posterior arthrodesis, a gradual correction
of the kyphosis occurs because of continued anterior vertebral body
growth. Because the posterior arthrodesis is performed at a young age,
the patient must be followed for potential complications from continued
anterior growth, which would result in lordosis. Johnston and
Schoenecker (273) described a patient who developed neurologic symptoms from this growth-related lordosis.

Kyphosis can occur as a direct result of trauma to the spinal column or the spinal cord. Deformity can occur at a

fracture site from a malunion, chronic instability leading to
progressive deformity, paralysis after spinal cord injury, or from
anterior growth arrest (274,275,276,277,278).
Kyphosis at the fracture site is acute and spans a short segment of
vertebrae. Paralytic kyphosis is a long, C-shaped deformity that spans
many vertebral segments. Progressive kyphosis may also occur after
development of a posttraumatic syrinx (279).

Kyphosis at a fracture site requires surgical
intervention for correction. Anterior, posterior, and combined anterior
and posterior procedures have been described for correction of
posttraumatic kyphosis (280,281,282,283,284). Brace treatment has been ineffective for progressive paralytic kyphosis (274),
and surgery is indicated for paralytic kyphosis of more than 60
degrees. If the kyphosis is flexible and can be reduced to less than 50
degrees, posterior fusion with segmental instrumentation can be
performed. If the kyphosis is rigid and cannot be reduced to less than
50 degrees on preoperative bending view x-ray films, anterior release

and fusion should be followed by posterior fusion and segmental instrumentation (274,278).

Kyphoscoliosis is common in patients with neurofibromatosis, although kyphosis may be the predominant deformity (285). Funasaki et al. (286)
found that 50% of their patients with neurofibromatosis and spinal
deformity had an abnormal sagittal curve. The vertebral bodies are
frequently deformed and attenuated at the apex of the kyphosis.
Dystrophic vertebral body changes may develop over time (287,288). Crawford (287,289)
described this as modulation of the deformity, from a nondystrophic
curve to a dystrophic curve. The kyphosis is typically sharp and
angular over a relatively small number of vertebral segments. Severely
angular kyphosis can cause neurologic compromise (290,291). Lonstein et al. (292)
found that cord compression due to spinal curvature from
neurofibromatosis was second only to congenital kyphosis as a cause of
spinal cord compression. The kyphosis in patients with
neurofibromatosis typically involves the thoracic spine or upper
thoracic spine. Involvement of the cervical and cervicothoracic
vertebrae has also been reported (290,293,294,295,296,297).

Kyphotic deformities with dystrophic changes tend to be progressive, and they more commonly lead to neurologic compromise.

Treatment of kyphoscoliosis in patients with
neurofibromatosis begins with a thorough physical examination for
neurologic abnormalities. MRI scans should be obtained to demonstrate
any intraspinal lesions, such as pseudomeningocele, dural ectasia, or
neurofibroma, which may cause impingement on the spinal cord (298).
Any intraspinal lesions should be treated appropriately before spinal
fusion and instrumentation are undertaken. Because posterior fusion
done alone has resulted in a high rate of pseudarthrosis (65%) (299), combined anterior and posterior spinal fusion combined with posterior instrumentation is recommended (300).
Titanium instrumentation is preferred so as to allow for future MRI
studies of the spine. Abundant autogenous bone grafts and prolonged
immobilization may be required in order to obtain a solid fusion in
these patients, and repeated bone grafting may be required 6 months
after the initial surgery. Vascularized fibular or rib grafts may also
be used for anterior fusion and structural support (99,287,293,296,301,302,303).

There is spine involvement in 50% of patients with skeletal tuberculosis (304).
Spinal tuberculosis is the most dangerous form of skeletal tuberculosis
because of its ability to cause bone destruction, deformity, and
paraplegia. In childhood spinal tuberculosis, the extent and degree of
abscess formation is greater than that seen in adult tuberculosis, but
paraplegia is less common in children than in adults with spinal
tuberculosis (305). The most frequent site of
spinal tuberculosis in children is the thoracolumbar junction and its
adjacent segments. Tuberculosis infection usually destroys the anterior
elements of the spine and results in a significant angular kyphosis at
the infected site. The involved anterior vertebral bodies usually fuse
once the infection is adequately treated. In young children, continued
growth of the intact posterior element can cause a late increase in
kyphosis in an already kyphotic spine (305).

All forms of active spinal tuberculosis are treated with
a complete course of chemotherapy. First-line drugs are streptomycin,
isoniazid, and rifampicin, and second-line drugs are ethambutol and
pyrazinamide (306). Medical therapies for spinal tuberculosis will adequately treat the tuberculum infection in most cases (304,307,308,309,310).
Bracing or casting has been used along with medical therapy to try to
prevent progression of kyphosis during therapy. Rajasekaran found an
average increase of 15 degrees in deformity in all patients who were
treated nonsurgically (311). The greatest increase in deformity occurred during the first 6 months of treatment.

Indications for surgery in spinal tuberculosis are
spinal instability, neurologic involvement, prevention or correction of
spinal deformity, drainage of significant abscesses, or diagnostic
biopsy (307). Neurologic involvement and
present or impending paraplegia are more obvious indications for
surgical intervention than the other indications. Rajasekaran described
four prognostic signs to predict spinal instability and late increase
in deformity. When more than two signs are present, this is a reliable
predictor of progressive deformity and spinal instability. These
prognostic signs include: (a) dislocation of the facets, (b) posterior
retropulsion of the diseased fragments, (c) lateral translation of the
vertebrae in the anteroposterior view, and (d) toppling of the superior
vertebra (Figs. 20.26 and 20.27) (312).
Other factors that lead to a significant increase in kyphosis in
children who are not treated surgically are involvement of three or
more vertebral bodies, initial kyphosis of more than 30 degrees, and
age younger than 15 years (313,314,315).

Several different surgical approaches have been used in the treatment of spinal tuberculosis (316,317,318,319,320).
Anterior debridement and strut grafting, with or without a posterior
fusion and instrumentation, has the most consistent long-term results (306,321,322,323,324,325,326,327,328,329,330,331,332). Good results have been reported with the use of allografts for structural support anteriorly (333,334,335).
Anterior debridement and fusion with anterior instrumentation of the
spine has also had positive results in the treatment of spinal
tuberculosis (336,337).
Some correction of the kyphosis may be obtained at the time of surgery.
Kyphosis can also be a problem in patients with healed spinal
tuberculosis (338). The infected area of the
anterior spine usually fuses, and continued growth posteriorly causes
progressive kyphosis that can result in paraplegia. The presence of
neurologic symptoms is an indication for anterior decompression and

fusion, which can be followed by posterior fusion and instrumentation.

Idiopathic juvenile osteoporosis is an acquired systemic
condition that consists of generalized osteoporosis in otherwise normal
prepubertal children (339). Although idiopathic
juvenile osteoporosis is uncommon, associated kyphosis and back pain
are common in patients with this condition.

Schippers (340) first described
this condition in 1939 and, since that time, other authors have
described its clinical findings and natural history (143,341,342,343,344,345,346,347).
The etiology of idiopathic juvenile osteoporosis is unknown. Laboratory
values of serum calcium, phosphorus, alkaline phosphatase, parathyroid
hormone, and osteocalcin are normal. The collagen type and ratios from
skin biopsy samples are also normal. There have been some reports of a
slight decrease in 1,25-dihydroxyvitamin D (345,348,349),
but the significance of this finding is not known. Low serum calcitonin
levels have also been reported, but treatment with calcitonin has not
proven to be beneficial (343,350). In contrast, Saggese et al. (346) noted normal serum calcitonin levels in their patients. Green (351)
believes that a mild deficiency of 1,25-dihydroxyvitamin D can explain
most of the findings in idiopathic juvenile osteoporosis. During rapid
growth phases the deficiency is discovered because growth requirements
cannot keep pace, causing a relative osteoporosis. When puberty occurs,
the increase in sex hormone overcomes the deficit in
1,25-dihydroxyvitamin D, and the relative osteoporosis improves. This
theory has yet to be proved.

Clinically, these patients complain of insidious onset of back pain (352), lower-extremity pain or fractures, and difficulty in walking (67,251,353,354).
Difficulty in walking may sometimes be the only finding. This condition
occurs during the prepubertal period, and is slightly more common in
boys than in girls. Vertebral collapse or wedging, with resulting
kyphosis, is common. Brenton and Dent (350)
classified idiopathic juvenile osteoporosis as mild, moderate, and
severe types. Patients with the mild type have only back pain and
vertebral fractures; those with the moderate type have back and
lower-extremity pain and fractures, with some limitation of activities
but eventual return to normal function; and those with the severe form
have back and lower-extremity pain and fractures. Both metaphyseal and
diaphyseal fractures can occur in the lower extremities. Patients with
severe disease improve clinically but do not return to normal activity
after puberty.

Plain radiographs show wedging or collapse of the
vertebral bodies. A “codfish” appearance of the vertebral bodies can
occur, with the superior and inferior borders of the vertebrae becoming
biconcave (Fig. 20.28). Other studies that can
be useful for following the progress of this disease are single-photon
absorptiometry, dual-photon absorptiometry, and quantitative CT
scanning (343,345,346). The problem with these tests is that normal ranges for adolescents and children are variable and have not been standardized.

Idiopathic juvenile osteoporosis is a diagnosis of
exclusion. Other diseases that must be considered include metabolic
bone diseases, leukemia, Cushing syndrome, lysinuric protein
intolerance, type I homocystinuria, and

osteogenesis
imperfecta. The natural history of this condition is spontaneous
improvement or remission at the onset of puberty. Associated kyphosis
tends to improve after the onset of puberty.

Treatment of idiopathic juvenile osteoporosis involves
modification of activities, possible calcium and vitamin D
supplementation, and supportive treatment of spinal deformities. It
must be ensured that there is sufficient restriction of activities in
order to prevent fractures, but not so much restriction as to cause an
increase in osteoporosis. If a significant progressive kyphosis
develops, the Milwaukee brace is the treatment of choice (344).
The brace is to be worn until there is evidence of improvement of the
osteoporosis. Operative therapy for this condition has been associated
with a high complication rate because the poor bone quality makes
instrumentation and fusion difficult (355).