A new technic for segmental spinal osteosynthesis using the posterior approach

The authors have designed a new method of instrumentation aimed at obtaining surgical fixation of the scoliotic curve without any postoperative external immobilisation. It is particularly strong and rigid and allows adequate reduction of the curve. This technique avoids the sublaminar space and thus prevents excessive blood loss and diminishes the danger of cord damage. The instrumentation is made of two parallel rough cylindrical rods inserted independently in the convexity and concavity of the curve. If necessary, they can be bent pre-operatively. They are attached to hooks placed on the laminae or pedicles, which are locked by bolts, thus allowing progressive straightening of the curve. They are joined by two transverse bars, one above and one below, to provide better rigidity to the device and to allow correction of rotation. The parts of the vertebrae left free by the device are denuded to allow the addition of grafts. Laboratory tests have demonstrated that this type of fixator is more rigid than the Harrington or Luque rods. Fifteen patients, either idiopathic or paralytic cases, were operated on without any neurological impairment. No loss of correction was observed since the hooks have been locked.