Reliability and Validity of Scoliosis Measurements Obtained with Surface Topography Techniques: A Systematic Review

Background. Surface topography (ST) is one of the methods in scoliosis assessment. This study aimed to systematically review the reliability and validity of the ST measurements for assessing scoliosis. Methods. A literature search of four databases was performed and is reported following PRISMA guidelines. The methodological quality was evaluated using Brink and Louw appraisal tool and data extraction was performed. The results were analyzed and synthesized qualitatively using the level of evidence method. Results. Eighteen studies were included and analyzed. Four were evaluated for reliability, six for validity, and eight for reliability and validity. The methodological quality of fourteen studies was high. Good to excellent intra-investigator reliability was shown on asymmetry, sagittal, horizontal, and most frontal ST measurements (evidence level: strong). Asymmetry and most frontal, sagittal, horizontal ST measurements showed good to excellent inter-investigator reliability (evidence level: moderate). When comparing corresponding ST and radiological measurements, good to strong validity was shown on most frontal, sagittal, and asymmetry measurements (evidence level: strong). Formetric measurements had good intra-investigator reliability and validity (evidence level: strong). Conclusions. Most asymmetry, sagittal, and frontal ST measurements showed satisfactory reliability and validity. Horizontal ST measurements showed good reliability and poor validity. The ST technique may have great potential in assessing scoliosis, especially in reducing radiation exposure and performing cosmetic assessments.