Ahead of Print: Magnitude of Sagittal Correction and HRQOL

Background: Sagittal plane malalignment has been established as the main radiographic driver of disability in adult spinal deformity (ASD).

Objective: To evaluate the amount of sagittal correction needed for a patient to perceive improvement (Minimal Clinically Important Difference, MCID) in health related quality of life (HRQOL) scores.

Methods: This was a multicenter, retrospective analysis of prospectively consecutive enrolled ASD patients. Inclusion criterion was a sagittal vertical axis (SVA group) >80mm. Demographic, radiographic, and HRQOL pre-operative and 2 year post-surgery data were collected. Surgical treatment was categorized based on SVA correction: <60mm, 60mm-120mm, and >120 mm. Changes in parameters were analyzed using paired t-test, one-way ANOVA, and chi-square test.

Free Article: Implications of Spinopelvic Alignment for the Spine Surgeon

The relation of the pelvis to the spine has previously been overlooked as a contributor to sagittal balance. However, it is now recognized that spinopelvic alignment is important to maintain an energy-efficient posture in normal and disease states. The pelvis is characterized by an important anatomic landmark, the pelvic incidence (PI). The PI does not change after adolescence, and it directly influences pelvic alignment, including the parameters of pelvic tilt (PT) and sacral slope (SS) (PI = PT 1 SS), overall sagittal spinal balance, and lumbar lordosis. In the setting of an elevated PI, the spineadapts with increased lumbar lordosis. To prevent or limit sagittal imbalance, the spine may also compensate with increased PT or pelvic retroversion to attempt to maintain anupright posture. Abnormal spinopelvic parameters contribute to multiple spinal conditions including isthmic spondylolysis, degenerative spondylolisthesis, deformity, and impact outcome after spinal fusion. Sagittal balance, pelvic incidence, and all spinopelvic parameters are easily and reliably measured on standing, full-spine (lateral) radiographs, and it is essential to accurately assess and measure these sagittal values to understand their potential role in the disease process, and to promote spinopelvic balance at surgery.