Impact of postoperative spinal malalignment on postoperative health-related quality of life after long-level fixation for degenerative lumbar scoliosis: does residual coronal angularity matter?

Abstract

This study evaluates the influence of spinal malalignment on health-related quality of life (HRQOL) in a long-level fusion spine. This was a retrospective analysis of 121 consecutive patients with DLS after long-segment fusion. HRQOL and radiographic parameters were collected at final follow-up. For postoperative residual Cobb angle (CA), patients were divided as follows: group (0) (CA < 10°), group (+) (CA 10°∼20 °), and group (++) (CA > 20°). For postoperative coronal vertical axis (CVA), patients were separated as follows: group (0) (CVA < 2cm), group (+) (CVA 2 ∼ 3cm), and group (++) (CVA > 3cm). Patients were also grouped by the sagittal modifiers as group (0), group (+), and group (++) according to the Scoliosis Research Society (SRS)-Schwab classification, respectively. Visual analog scale (VAS) for back was significantly lower in CA 10°∼20° group compared to other groups. Patients with remnant CA > 20° showed worse Oswestry Disability Index (ODI), SRS-22 and the 36-item Short Form Health Survey (SF-36) - physical component scores (PCS). Sagittal vertical axis (SVA) showed significant correlation with HRQOLs after surgery, and the statistical significance of ODI, SRS-22 and SF-36 scores was observed among subgroups. In long-level fused spine, residual CA > 20° resulted in worse clinical outcomes and was recommended to avoid during surgery. And 10° to 20° residual CA was acceptable in DLS patients and even better than Cobb angle < 10° in several HRQOLs, therefore strictly pursing upright alignment seems unnecessary. SVA also showed effectiveness in assessing HRQOL in the fixed spine.