Effect of higher implant density on curve correction in dystrophic thoracic scoliosis secondary to neurofbromatosis Type 1

Abstract

OBJECTIVE The aim of this study was to investigate how implant density affects radiographic results and clinical outcomes in patients with dystrophic scoliosis secondary to neurofbromatosis Type 1 (NF1). METHODS A total of 41 patients with dystrophic scoliosis secondary to NF1 who underwent 1-stage posterior correction between June 2011 and December 2013 were included. General information about patients was recorded, as were preoperative and postoperative scores from Scoliosis Research Society (SRS)-22 questionnaires. Pearson correlation analysis was used to analyze the associations among implant density, coronal Cobb angle correction rate and correction loss at last follow-up, change of sagittal curve, and apical vertebral translation. Patients were then divided into 2 groups: those with low-density and those with high-density implants. Independent-sample t-tests were used to compare demographic data, radiographic fndings, and clinical outcomes before surgery and at last follow-up between the groups. RESULTS Signifcant correlations were found between the implant density and the coronal correction rate of the main curve (r = 0.505, p < 0.01) and the coronal correction loss at fnal follow-up (r =-0.379, p = 0.015). There was no signifcant correlation between implant density and change of sagittal profle (p = 0.662) or apical vertebral translation (p = 0.062). The SRS-22 scores improved in the appearance, activity, and mental health domains within both groups, but there was no difference between the groups in any of the SRS-22 domains at fnal follow-up (p > 0.05 for all). CONCLUSIONS Although no signifcant differences between the high-and low-density groups were found in any of the SRS-22 domains at fnal follow-up, higher implant density was correlated with superior coronal correction and less postoperative correction loss in patients with dystrophic NF1-associated scoliosis.