A pilot study of scoliosis assessment using radiation free surface topography in children with GMFCS IV and V cerebral palsy

Background: Prevalence of scoliosis in cerebral palsy (CP) parallels the extent of neurological impairment and causes significant morbidity. Monitoring is important but requires regular radiological investigation. Surface topography provides a non-radiological approach to scoliosis monitoring.

Aim: To evaluate validity, reproducibility and feasibility of Quantec® scans to monitor scoliosis in children with severe CP.

Methods: Twenty non-ambulant children with CP, Gross Motor Function Classification System (GMFCS) grade IV/V had clinical, radiological and Quantec spinal assessment. The children were supported during scans using a seating system specifically designed for this study. Validity was assessed by comparing Quantec (Q) angle with gold standard (Cobb angle), reproducibility analysed using Bland-Altman plots and feasibility assessed using a questionnaire.

Results: Prevalence of scoliosis on radiological examination was 65%. Of these children, 85% had curves with Cobb angle less than 28°. Quantec scanning was feasible with appropriate postural support. Mean (and standard deviation) for differences between Cobb and Quantec (Q) angle were 0.02° (6.2°) and for Quantec inter-observer variability were 0.5° (5.8°).

Conclusions: Quantec scanning was feasible, reproducible and had good validity when compared with Cobb angle in a supportive seating system. To consolidate these findings a further study needs to be undertaken with larger number of children with Cobb angles between 25° and 45°.