Phase IV Comparing Rods of Yield Strengths to Correct Adolescent Idiopathic Scoliosis.

A Multi-Centre Randomized Phase IV Clinical Trial Comparing Rods of Varying Yield Strengths and Their Ability to Hold Correction of Adolescent Idiopathic Scoliosis.

There has been a growing trend amongst surgeons to use a construct for correction of scoliosis which involves segmental instrumentation with pedicle screws. Pedicle screw proponents cite greater curve control in all planes, which results in improved spinal curve correction. Some surgeons have noted due to the increased strength of the all screw construction that the rod is now the weak part of the spinal fixation. Although no evidence has been raised in regards to hardware failure there is a perception that a loss of balance in the sagittal plane is the result of flex in the titanium rod. A novel solution to the issue of rod flexibility is raised with the expedium super steel instrumentation which allows for greater stiffness than a 5.5 mm titanium rod with the same lower profile. This study aims to compare the new super steel technology with other established instrumentations used to correct spinal stenosis.

Inclusion Criteria: aged 10-20; presenting with a progressive lenke type 1A, N; or type idiopathic adolescent scoliosis measuring greater than 45 degree cobb angle Exclusion Criteria: rigid scoliosis requiring a three column release or osteotomy; patients that can not have pedicle screw instrumentation due to technical concerns