Spinal
deformity
This is a lateral curvature of the spine hut is usually accompanied by a
rotational deformity as the spinal column starts to buckle and shorten. In the
thoracic region the rotation throws the ribs into prominence producing the
cosmetically deforming rib hump (Fig. 28.35a and b) whereas in the lumbar region
the same degree of curvature may not be so noticeable. A curve is described as structural
or fixed when there is loss of mobility in the involved segment. This
usually occurs because of alterations in the shape of the vertebrae and adaptive
changes in soft tissues. A curve is mobile when normal flexibility is
preserved; such curves are often described as postural although strictly
speaking the terms are not interchangeable. A postural curve is secondary to the
position of the body, one of the commonest causes being leg-length inequality.
Curves are also described on the basis of their anatomical site and whether they
are primary (major) or secondary (compensatory) to the primary
curve in an attempt to maintain spinal balance.
Idiopathic scoliosis is the commonest type and is usually considered in
three sub groups.
Infantile
idiopathic scoliosis may be related to sleeping position. It is usually noted
between birth and the age of 1 year. It is often a component of the ‘moulded
baby syndrome’ (plagiocephaly, tight hip adductors, scoliosis, foot deformities).
The curves are usually convex to the left and are more common in males. The
great majority resolve without treatment but approximately 10 per cent progress
and pose difficult problems. Serial examination and radiographs are important to
detect progressive cases. Measurement of the rib—vertebra angle difference (Mehta)
is helpful in predicting which cases are likely to progress. Treatment is
initially by bracing but if unsuccessful there is an indication for anterior
release of the affected spinal segments.
Juvenile
idiopathic scoliosis. This occurs between the ages of 3 years and puberty. The
distinction between juvenile and early adolescent curves is ill defined.
However, juvenile curves frequently progress and early bracing is advisable.
Adolescent idiopathic scoliosis is the commonest form and occurs at puberty. It is slightly more common in girls and usually convex to the right. A number of different patterns of curve has been described depending on site and distinguishing between the major and compensatory curves. Appreciation of the patterns is important in assessing the extent and level of spinal fusion. In general, treatment is required for all curves that are progressing.
The
following are important factors in assessing progression.
• Sex. Progression is more common in girls.
• Age. Progression is more likely when there is potential for skeletal
growth. Curves presenting before menarche have
• Curve pattern. Double curves are more likely to progress than single
thoracic curves which in turn are more likely to progress than lumbar curves.
• Curve magnitude. Progression is more likely with curves over 300.
• Other factors. Patients with slender spines are more likely to
progress.
Treatment.
Idiopathic scoliosis can only he treated by bracing and surgery. In general,
curves which measure less than 30degree should
be managed nonoperatively with regular clinical and
Surgery
is generally indicated when:
—
the curve is too large, i.e. >450
—
the site makes it difficult to brace, e.g. high thoracic or true double
thoracic curve,
—
the curve is fixed;
• the curve is deteriorating in a young child;
• there is loss of spinal balance;
• the cosmetic appearance needs correction.
Congenital
scoliosis
This is usually due to a failure of formation, e.g. hemivertebra (Fig.
28.38) or failure of segmentation, e.g. a bar. Mixed patterns can occur and the
anomalies may be single or multiple. Associated abnormalities are
diastomatomyelia, and cardiac and renal malformations. A unilateral
unsegmented bar with a contralateral hemivertebra at the same level along with
thoracolumbar anomalies are associated with particularly severe curves. In
general, early fusion in situ should be undertaken for curves that are
progressing or likely to progress. On occasions, other procedures may be
appropriate such as hemivertebra excision or growth arrest operations.
Tumours
Other
conditions
A kyphosis is normally present in the thoracic spine but more than 45degree is considered to be excessive. The deformity may be idiopathic or occur
as a result of:
• congenital abnormalities such as anterior bony bar;
• developmental delay, e.g. cerebral palsy;
• vertebral collapse, e.g. infection, osteoporosis, sickle cell disease
(Fig. 28.39a—c).
There is a spectrum of idiopathic scoliosis. In Scheuermann’s disease, the
kyphosis is associated with radiological changes such as irregular vertebral end
plates, apparent narrowing of the disc space and wedging of one or more
vertebrae. These changes make the kyphosis more rigid than the less severe postural
round back in which radiographs are normal. Apart from the cosmetic
deformity, Scheuermann’s disease may be associated with back pain, especially
after skeletal maturity and, in severe cases, brace treatment and occasionally
fusion may be justified.