Abstract
Background: To assess the potential for Quantec imaging to save radiographs in the follow-up of patients with early onset scoliosis. This is a group of patients who often have many radiographs due their age at diagnosis.
Methods: This is a prospective cohort study. Twenty-four children with early onset scoliosis are identified. They all have a minimum of three simultaneous radiographs and Quantec scans as part of routine follow up for their scoliosis curves. There are 15 males and 9 females (22 thoracic, 1 thoracolumbar, 1 lumbar). Mean age at diagnosis is 3 years (range 1–4.8 years). The Cobb angle of the major curve is measured from each radiograph and compared with the Q-angle using Bland-Altman plots and linear regression analysis.
Results: The mean Cobb angle was 30° and the mean Q-angle 19°. The correlation coefficient was 0.68 (p< 0.05). In curves with Cobb angle < 30°, The Bland-Altman plots show a close scatter with a mean difference of 3.4°. It was calculated that this could have safely saved 18 radiographs in 14 patients. In curves > 30°, there was a large scatter and a mean difference between Cobb angle and Q-angle of 20.1°.
Conclusion: In early onset scoliosis, curves with Cobb angle less than 30° can be safely followed clinically and with the Q-scan reducing the number of radiographs required. Curves with Cobb angle greater than 30° cannot be reliably observed with Quantec scans alone.
The abstracts were prepared by Mr Colin E. Bruce. Correspondence should be addressed to Colin E. Bruce, Consultant Orthopaedic Surgeon, Alder Hey Children’s Hospital, Eaton Road, Liverpool, L12 2AP.
