Fifty-eight patients who had scoliosis or kyphosis of varying etiologies
were followed for a minimum of two years (average, forty-four months) after
segmental spinal instrumentation using sublaminar wires. In eight (19 per
cent) of the patients who had been operated on for scoliosis one or both
rods broke. The average time that had elapsed before the breakage was
discovered was twenty-three months. None of the patients in whom a rod had
broken had had postoperative immobilization or a first-stage anterior
fusion, and only one had had supplementary grafting with banked bone.
Instrumentation to the pelvis was also associated with a greater incidence
of broken rods. The use of supplementary grafting with banked bone or the
use of postoperative immobilization significantly decreased the loss of
postoperative correction. Preliminary anterior spinal fusion helped prevent
breakage of rods but not loss of correction. It was concluded that
postoperative immobilization and use of large amounts of supplementary bone
graft lead to better results when using this implant system.