Abstract
Introduction
There is no consensus among scoliosis surgeons on which surface topography method and parameters may be used as an alternative to serial radiography to monitor scoliosis progression. The aim of this study was to evaluate the inter-correlation among surface rotation (4-D formetric II) with 3-D Quantec scan and 2-D cobb's angle measurements for assessing torso asymmetry in adolescent idiopathic scoliosis (AIS).
Materials & Methods
A prospective cohort of consecutive 24 patients with adolescent idiopathic scoliosis was accrued from the departmental scoliosis surface topography database. This group comprised of conservatively treated, Spinecor brace treated and postoperative patients in order to assess the wider utility and validity of 2 different surface topography methods (Formetric II & Quantec Spinal Imaging System). Parameters assessed were Q-angle, Suzuki hump sum, Posterior Trunk Symmetry Index (POTSI), surface rotation (rms), surface rotation (max) and maximum Cobb's angle on concurrently done scoliograms.
Results
There were 3 male and 21 female patients (87.5%) at a mean age of 14.1 years (range, 10-20 years). Maximum Cobb's angle ranged from 9 degrees to 80 degrees. There was a significant correlation between Cobb angle (mean-35.1°) and Q-angle (mean-21.8°). Scatter plot and regression analysis showed a linear relationship between surface rotation (mean-9.9 root mean square) and POTSI (mean-42.5) as well as Q-angle. Suzuki hump sum was a less reliable parameter.
Conclusions
Formimetric scans showed a linear correlation and reproducibility in patients with AIS receiving conservative treatment for smaller magnitude curves, when compared to Quantec scan. Due to ease of use, colourful and multi-mode representation of spinal deformity, Formetric may have an edge of preference for better clinic consultation to patient/parental appreciation of cosmetic issues and gain following treatment.
