Rasterstereography versus radiography for assessing shoulder balance in idiopathic scoliosis: A validation study relative to patients' self-image.

Abstract

Shoulder imbalance is a problem for scoliosis patients. Rasterstereography uses radiation-free surface topography to follow up these patients. Its use for assessing shoulder level has not been investigated earlier. This study aimed to determine the accuracy of shoulder assessment using rasterstereography (versus radiography) and to analyze its relationship with patients' self-image. In a cross-sectional setting, the reliability and validity of five rasterstereographic shoulder variables were measured in comparison with six radiographic shoulder parameters, using correlation analysis. The patients' self-perception was documented using the Scoliosis Research Society-22 (SRS-22) questionnaire and Trunk Appearance Perception Scale (TAPS). Forty patients were included in the study. The test-retest reliability of all rasterstereographic shoulder parameters was excellent (ICC > 0.95). The validity was moderate in comparison with six radiographic parameters (highest coefficient: 0.582). The radiographic and rasterstereographic shoulder levels correlated with the results in the SRS-22 questionnaire (highest coefficient: -0.463) and TAPS (highest coefficient: 0.413). Rasterstereography is a reliable and valid method for assessing shoulder level in idiopathic scoliosis. The parameters can be recommended as a complement to radiography and clinical evaluation for follow-up purposes. Radiographic and rasterstereographic shoulder parameters are significantly related to patients' self-perception. Shoulder variables thus need to be considered in scoliosis patients.