The purpose of this study was to establish the a)feasibility, b) reproducibility of spinal Quantec scans (a non-intrusive surface topography system) and c) the validity of the Quantec Q-angle against Cobb angles from spinal radiographs, in non-ambulant children with cerebral palsy (CP). Eighteen non-ambulant children (aged 5–11 years) with CP had successful clinical, radiological and Quantec assessment of their spine while seated in a supportive seating system. Scoliosis incidence was 72%, Cobb angles ranged from 1–73° (mean 18.2°). Quantec scanning was feasible with appropriate postural support. Mean interobserver differences were 0.5 ± 5.8° (median 1.3°, 5 / 95th percentiles lying at −7.3 / 8.5° respectively). Mean differences between Cobb and Q-angle were 0.02 ± 6.2° (median 1.0°, with 5 / 95th percentiles lying at −8.2 / 7.7° respectively). Surface topography may be used to safely monitor the spine for non-ambulant CP children. Results show similar or improved trends to previous comparisons with idiopathic scoliosis. Ovadia (2007) showed an interobserver mean difference of 6.3 ± 4.9° using an Ortelius800TM system. Thometz (2000) showed mean differences between Cobb and Q-angle ranging from 1.1–12.6 ± 4.9–10.2°. Further research is needed for the user group described in this study with larger spinal curves.
