1)Paper:

Title:
Surgical Correction of spinal curvatures by means of in situ rod contouring The evolution of ideas over six years of practice.

Surgical correction of scolioses is three-dimensional. While the Harringtontechnique treats one plane without being concerned about vertebral rotation, the Cotrel-Dubousset (CD) technique, which relies on rod rotation, has led to confusion through its action in both the frontal and the lateral planes. We now know that this technique resolves vertebral rotation only slightly, if at all (+1.1 degrees at the level of the superior end vertebra, -2.3 degrees at the level of the inferior end vertebra, and -0.4 degrees at the apex). It is from these findings that the idea of in situ rod contouring was developed, in which reduction is obtained by bending the rod ム alternating between the frontal and the sagittal planes, and adapting the method according to the segment being treated. In the thoracic region correction efforts are directed inwards and towards the rear. The combined effect of these two forces on the pedicular hook turns the vertebra and corrects the vertebral rotation. At the lumbar level, correction efforts are directed inwards and towards the front. At this level, as well as bending the rod, convex screws are applied along the axis of the rod to obtain the desired rotation. Distraction and compressive maneuvers are not necessary for the correction; the forward movement of the apex vertebra imposes a displacement on adjacent vertebrae. These principles have changed the rules for spinal instrumentation; laminar hooks have been rejected in favor of pedicular implants (both screws and hooks). Vertebral derotation is assessed by calculating intervertebral rotation independently of any spatial reference point. The correction obtained by in situ contouring is significantly better for all of the instrumented vertebrae (p=0.015) and for the apex vertebrae (p=0.003). Clinical and radiographic results are stable at six years follow-up.

2) Workshop:

Title:
Instrumenting the scoliotic spine with the Spine Clip System, and reduction through in situ contouring.

A model of the spine, complete with the soft tissues, will be used; presenting a scoliosis with vertebral rotation. Employing a posteriorapproach, the spinal column will be instrumented with screws and hooks. A rod will be placed in the implants (thoracic concavity, lumbar convexity)
and will be contoured in situ to obtain correction in all three spatial planes. Lumbar screws will be applied about the rodユs axis. A second, stabilizing, rod will then be inserted (thoracic convexity, lumbar concavity). No distraction or compressive maneuvers are necessary for the
correction.