- See:
Crankshaft Phenomenon:
- Progressive Congenital Scoliosis:
- fundemental procedure for congenital scoliosis is posterior spine fusion w/o instrumentation;
- in young children correction of congenital scoliosis w/ instrumentation carries a higher risk of neurologic injury;
- in older children w/ congenital scoliosis, instrumentation & correction of deformity may be
done if
tethering of spinal cord has been ruled out;
- posterior fusion is performed on both convex & concave sides of curve because arthrodesis
performed only on convex side only tend to bend with time;
- the exception to this, however, is when a convex fusion is combined with hemi-epiphysiodesis;
-
anterior and posterior spinal arthrodesis:
- indicated for deformities with known high
risk of progression (such as concave bar
with convex
hemivertebrae);
- curve correction occurs through the angulated vertebrae adjacent to actual
congenital bar
or
hemivertebrae, & not thru congenital deformity;
- Surgical Considerations:
-
Harrington distraction rods may be dangerous in congenital scoliosis,
because of dysraphic problems;
- distracting a
tethered cord is likely to produce paralysis;
- shortening of a long (convex) side of the curve can be preferable to lengthening of a short (concave) side;
- use of subQ Harrington rod, which involves exposure of spine at ends of rod for hook insertion,
has been successful when vertebrae adjacent to hooks are fused;
- rod must be distracted periodically (every six months) & spine must be braced until arthrodesis
of the remainder of curve is performed when child is older (10 years of age or older);
-
crankshaft phenomenon
- in skeletally immature pt, isolated posterior arthrodesis w/ instrumentation of a lordotic curve
may act as a posterior tethering bar, producing lordosis & bending of the fusion mass
as the unfused anterior vertebral bodies continue to grow;
