Adolescent Idiopathic Scoliosis: Evaluation on the Effect of Screw Density in the Correction

Abstract

Objective: The objective was to investigate implant density or the number of screws correlated with the correction of the main curve in patients undergoing surgery for adolescent idiopathic scoliosis (AIS). Methods: We evaluated 112 medical records: 33 patients with screw density of up to 50%, and 79 patients with a density of 100%; all patients underwent surgical correction by posterior approach with transpedicular fixation. Results: In the group of patients with screw density of up to 50% the residual Cobb median was 10°; in the group with 100% density, the median was 7°. Conclusion: Biostatistical analysis showed that the group with up to 50% of screw density presented correction rate of 82.1% and the group with 100% density had correction of about 86.8%. It is therefore concluded that the difference is statistically significant in favor of the fixation with 100% density (p =0.010).

Surgical Outcome of Three-Dimensional Correction of Adolescent Idiopathic Scoliosis

“…In this study, the mean preoperative Cobb was 51.8°, ranging from 40° to 81°, while mean postoperative Cobb was 8°, ranging from 3° to 25°, with significant decrease in Cobb immediate and 1 year postoperatively when compared to preoperative level (p < 0.001 for both). Similar results were reported by Garcia et al (10) who included 79 patients and there was a statistically significant difference in the postoperative Cobb angle as compared to the preoperative Cobb angle (7° vs 53°) respectively. The results of the current study also agree with Kilinc et al (11) who showed that the preoperative mean main thoracic Cobb angle measured 61.2° and corrected to 25.3° postoperatively, and was 28.5° at 2-year follow-up.…”