CoCr rods provide better frontal correction of adolescent idiopathic scoliosis treated by all-pedicle screw fixation

Pedicle screw fixation is considered biomechanically advantageous in adolescent idiopathic scoliosis (AIS) correction, because it uses as an anchor the pedicle, which is the hardest part of the vertebral body. The ability of the rod to correct and hold the correction is a key factor in the selection of rod material. The goal of this study was to compare the results obtained by stainless steel (SS) and cobalt–chromium (CoCr) rods materials for the treatment of AIS curves. Ninety patients were retrospectively included. Sixty-four patients (group 1) were operated on using CoCr rods. Twenty-six patients (group 2) were operated on using SS rods. All the patients were treated by the same surgeon using all-pedicle screw constructs. In group 1, the correction was respectively 41.03° and 35.78° for main and secondary curves. In group 2, the correction was respectively 30.98° and 24.42° for main and secondary curves. Statistical analysis showed improved correction rates in patients operated with CoCr rods for main (P