Is There a Difference in Outcome between Top and Side Loading Instrumentation System Used for the Surgical Treatment of Adolescent Idiopathic Scoliosis (AIS)

Abstract

Different new instrumentation system are available for the surgical treatment of patients with Adolescent Idiopathic Scoliosis (AIS) with more recent emphasis in the three dimensional deformity correction, restoration of normal sagittal alignment and patient based functional out comes. Different surgical approaches and techniques can be utilized for the deformity correction which includes derotation, compression and distraction, in situ bending, and translation. Method: This retrospective study compared two instrumentation technique used to treat AIS, top loading (group I) and side loading (group II) looking at deformity correction, scoliosis research society-30 questionnaire and cost of instrumentation. The hypothesis was that there is no difference in final outcome between the 2 groups. Results: A total of 30 patients (15 in each group) were randomly selected. Mean age was 13.7 years (12.1-17.3), all were female, main curve cobb angle was 63o (41-81) both groups were very similar in their pre operative parameters. Post operative SRS-30 score, percent curve correction, number of instrumented vertebrae were similar between the two groups. The cost of instrumentation was significantly higher in group 2 (7,147 USD for group one and 11,536 USD for group two) which is 38% higher. There was one minor complication in each group. Conclusion: Top and side loading instrumentation systems utilized in this study gave a very similar post operative results and functional out come with significant cost difference, which might be something to consider when allocating resources and implant purchase and cost for these procedures.