Radiological analysis of the sagittal profile of the Colombian population according to the theoretical Roussouly classification

Abstract Background The theoretical Roussouly classification describes sagittal spinal profiles based on pelvic morphology. As most reference data originate from Caucasian populations, its applicability to Hispanic populations remains limited. This study aimed to describe sagittal spinal alignment in an asymptomatic Colombian population using the theoretical Roussouly classification. Methods A retrospective cross-sectional study analyzed whole-spine standing radiographs (2020–2024) from asymptomatic adults aged 18–50 years at Clínica Tolima. Spinopelvic parameters were measured using Surgimap, and sagittal profiles were classified according to the theoretical Roussouly classification. Results A total of 792 participants (57.58% female) were included. All sagittal profile types were identified. Type 3 was the most prevalent (36.74%), followed by Type 4 (28.16%); Type 3 Anteverted Pelvis (AP) accounted for 11.11%. Strong correlations were observed between Pelvic Incidence (PI) and Sacral Slope (SS) (r = 0.82), PI and Lumbar Lordosis (LL) (r = 0.88), and SS and LL (r = 0.79) (all p < 0.001). Sex was associated with higher SS and LL values, while age showed a limited association with SS only. Conclusions Sagittal profile distribution and spinopelvic relationships in this Colombian population were comparable to those reported in other ethnic groups.