Журнал позвоночника и нейрохирургии

A Single Sagittal Parameter for Decision Making in Adult Spinal Deformity

David Christopher Kieser, Louis Boissiere, Caglar Yilgor C, Daniel Larrieu, Takashi Fujishiro, Ahmet Alanay, Emre Acaroglu, Frank Kleinstueck, Ferran Pellisé, Francisco Javier Sanchez Perez-Grueso, Anouar Bourghli, Derek Cawley, Jean-Marc Vital, Olivier Gille and Ibrahim Obeid

Objective: Decision-making in adult spinal deformity (ASD) remains challenging with complex algorithms and scores inhibiting every day use. Thus, there is an appetite for a simplified parameter to be identified that can guide surgical decision-making. This study therefore questions whether a simplified sagittal modifier (SSM) or relative spinopelvic alignment (RSA) could offer a reliable tool to determine operative intervention in patients with ASD. Methods: Multicenter, prospective study of consecutive ASD patients. Inclusion criteria were ASD patients presenting with at least one criteria: Cobb ≥ 20°; SVA ≥ 5 cm; TK ≥ 60° or PT ≥ 25°. A total of 1238 patients (431 non-operative and 807 operative) were classified according to their SSM and RSA. A Chi2 test was performed for surgical indication (operated or not). p<0.05 value was considered significant. Results: For non-operative patients: 235 (55%) were classified as aligned with SSM and 323 (75%) with the RSA; 157 (36%) vs. 39 (9%) respectively as moderate and 39 (9%) vs. 69 (16%) respectively as severe malalignment. For operative patients: 252 (31%) vs. 388 (48%) respectively were classified as aligned, 289 (36%) vs. 96 (12%) respectively as moderate and 266 (33%) vs. 323 (40%) respectively as severe malalignment with each respective modifier. Both modifiers were significant (p<0.01) for decision-making. Conclusions: Both the SSM and RSA are significantly correlated to the intention to surgically treat patients with ASD. RSA is a simple and powerful parameter that is more discriminant than SSM in decision-making. RSA should be considered as a parameter that can guide the decision for surgical intervention in patients with ASD.