Restoration of the sagittal profile according to the Roussouly classification reduces mechanical complications and revision surgery in older patients undergoing surgery for adult spinal deformity (ASD)

Purpose: The mechanical complications related to ASD remain a concern due to their morbidity and associated revision surgery. Restoration of each patient's Roussouly profile may reduce these. Our aim was to examine if the restoration of the Roussouly profile reduced these complications and revision rates in older patients operated for degenerative ASD.

Methods: Retrospective analysis of a single-centre, 2-year minimum follow-up patient database. All patients undergoing corrective surgery (≥ 4 levels) for ASD were included with analysis of demographic data, operative records, restoration of Roussouly sagittal profile, mechanical complications and revision rates. Univariate and multivariate analysis was conducted.

Results: Fifty-two patients were included (mean age was 72.3 years, average follow-up 56.3 months). Twenty-six patients had a "restored" profile (50%) and 26 an "unrestored" profile (50%). The incidence of mechanical complications was 7 (27%) and 23 (88%) for the restored and unrestored groups, respectively (p < 0.001). Revision rates were 4 (15.4%) and 18 (69.2%), respectively (p < 0.000), in the restored and unrestored profiles. Univariate analysis determined that profile restoration and BMI were associated with mechanical complications and revision surgery, whilst only the profile restoration status maintained its statistical power in multivariate analysis (p = 0.002 and p = 0.002, respectively). Age was not a significant factor in univariate analysis. The relative risk for mechanical failure and revision surgery was 5.6 times (CI 1.929-16.39) and 3.08 times (CI 1.642-5.734) greater if the profile was not restored.

Conclusions: Achieving each patient's ideal Roussouly profile is associated with a reduced incidence of mechanical complications and revision rates in the older population after surgery for degenerative ASD.