Minimally Invasive Surgery vs Standard Posterior Approach in the Treatment of Developmental Idiopathic Scoliosis

The minimally invasive technique, involves two small median skin incisions that allow the deep structures to be exposed. The muscle fibers are separated from the bony insertion by the process of subperiosteal "skeletonization." The Investigators then proceed with the arthrectomy of the levels to be instrumented and the infiltration of pedicle screw pairs of the appropriate caliber according to the "free-hand" technique. After amplioscopic control of proper screw placement, osteotomies of the posterior elements are performed to facilitate correction of the metameres.

The standard open technique involves a longitudinal incision along the midline extended along the entire thoracolumbar spine, the paravertebral muscles are incised and spread apart to expose the posterior vertebral structures, in a stretch extending more than 30 cm. The series of facetectomies are performed first, and then pairs of pedicle screws are infixed freehand. After performing the osteotomies necessary to mobilize the vertebral metameres at the apex of the deformity, correction by derotation maneuvers is continued, and the obtained correction is fixed with pre-shaped bars that are then connected to the screws and tightened to the nuts by dynamometric technique. Almost all vertebral levels of the thoracolumbar tract are included in the arthrodesis