Reliability, repeatability and comparison to normal of a set of new stereophotogrammetric parameters to detect trunk asymmetries

Aesthetic impairment is a crucial issue in Adolescent Idiopathic Scoliosis (AIS), but to date no objective measurements are available. The aim of the study is to evaluate the repeatability of 17 parameters measured by surface topography in a group of AIS subjects and verify their diagnostic validity. The paper is divided into three cross-sectional observational studies. We evaluated 17 selected surface topography parameters that could be good predictors of scoliosis' impact on the patients' trunk. We analysed short-term (30 seconds, 38 subjects) and medium-term (90 minutes, 14 subjects) repeatability of surface topography measures and their diagnostic validity in AIS (74 subjects, 33 AIS patients and 41 healthy subjects). All examined parameters were highly correlated as far as short and medium-term repeatability is concerned. We found a statistically significant difference between the scoliosis group and the control group in 3 surface rotation parameters, 1 shoulder parameter and 3 waist parameters. In conclusion, surface topography showed a good repeatability. Moreover, some of its parameters are correlated with AIS, enabling us to find differences between pathological and healthy subjects. Thanks to these findings, it will be possible to develop a tool that can objectively evaluate aesthetics is AIS patients.