- Discussion:
- deformity is characterized by severe angular deformity with a prominent gibbus at the apex of the curve;
- etiology involves either failure of
segmentation or defect in
formation of vertebral body elements;
-
defect of formation:
- failure of formation of the anterior elements produces the worst deformity;
- prognosis for defect in formation is considerably worse;
- natural history involves relentless progression of deformity;
-
sequelae:
-
paraplegia commonly results if untreated;
- breakdown of the overlying soft tissues;
- compression of the abdominal viscera;
- impairment of pulmonary function;
- poor sitting posture;
-
defect of segmentation:
- slightly better prognosis;
- produces a more rounded kyphotic shape;
- deformity progresses more slowly and paraplegia is uncommon;
- Associated Conditions:
-
congenital scoliosis:
-
mucopolysaccharidoses:
-
spondyloepiphyseal dysplasia congenita:
- Posterior Fusion:
- in children
< 5 yrs w/ curves
< 55 deg, only an situ posterior arthrodesis is required since
some spontaneous correction of kyphosis will occur with continued growth;
- posterior fusion may have wider indications w/ kyphosis due to failure of
segmentation (as opposed to failure of formation);
- posterior kyphectomy & arthrodesis involve meticulous care of tissues;
- resection of the non-functioning cord at apex of the deformity;
- water-tight dural closure, w/ care being taken not to occlude terminal
end of normal spinal cord at site of transection of cord;
- bivalve total-contact orthosis is used to support trunk until fusion is solid;
- Anterior & Posterior Fusion:
- combined anterior & posterior fusion is indicated for children
> 5 years, and curves
> 55 deg;
-
paralytic deformity:
- reconstruction begins w/ anterior release w/ interbody arthrodesis;
- decompression of spinal cord anteriorly is required;;
- as a staged procedure, posterior arthrodesis is followed by segmental spinal fixation to pelvis;
-
reduction:
- correction of kyphotic defomrity carries a high risk of paraplegia, esp when it is tried preoperatively w/ traction;
- this will stretch cord over fixed kyphotic deformity;
- congenital kyphosis may be corrected intraoperatively if intra operative cord monitoring if available;
-
anterior arthrodesis:
- requires
strut graft as well as
interbody arthrodesis;
- anterior unsegmented bar will develop in growing child if interbody arthrodesis is not added to procedure
since unfused vertebral bodies will continue to grow & contribute to the deformity;
- strut graft is placed as close to vertebral bodies as possible to reduce the risk of pseudoarthrosis;
-
vertebral resection:
- w/ severe deformity present at birth, vertebral resection and a short
arthrodesis may be required for closure of overlying soft tissues;
- loss of correction with growth is common, and arthrodesis of entire spine may be required by age 10 yrs;
Congenital kyphosis due to defects of anterior segmentation.
Kyphosis in childhood and adolescence.
Spine 1978;3:285-308.
Winter RB, Hall JE:
