Purpose: The aim of this study was to compare radiographic sagittal spinopelvic parameters between skeletally immature and skeletally mature patients with Scheuermann's disease (SD).
Methods: Cross-sectional analysis of standing postero-anterior and lateral radiographs of the spine of patients with SD was performed. Sagittal vertical axis (SVA), thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS) were measured on the lateral radiographs. Risser's sign was assessed on the postero-anterior radiographs. All of the parameters measured were compared between skeletally immature (Risser's sign 0-3) versus mature patients (Risser's sign 5). PI, PT, and SS in both groups were compared to PI, PT, and SS reported for normal children, adolescents, and adults.
Results: Sixty-six patients with SD (33 immature and 33 mature) were retrospectively reviewed and included in the study. There was no significant difference between the two groups of SD patients in: SVA (-16.6 vs. -22.9 mm, p = 0.74), TK (57.8° vs. 56°, p = 0.66), TLK (7.8° vs. 11.7º, p = 0.14), LL (63.2° vs. 62.2°, p = 0.74), PI (36.7° vs. 39.4°, p = 0.20), PT (3.8° vs. 7.3°, p = 0.10), and SS (32.8° vs. 32.1°, p = 0.75). Both, the immature and mature group of SD patients presented significantly lower PI and SS than normal children, adolescents, and adults, and significantly lower PT than normal adults.
Conclusions: There is no significant difference in sagittal spinopelvic parameters between skeletally immature and mature subjects with SD. Pelvic incidence in both groups of SD patients was significantly lower than PI in normal children, adolescents, and adults. This challenges the role of PI in predicting desired LL in patients with SD.