Long-term Postural Stability Changes After Correction of Spinal Deformity: A prospective, controlled pilot study.

Abstract

Study design: Prospective cohort study.

Objective: This study aimed to investigate the durability of postural stability after ASD correction surgery and its' association with clinical outcomes.

Summary of background data: The prevalence of symptomatic adult spinal deformity (ASD) necessitates surgical intervention, aiming to correct global spinal balance and spinopelvic parameters. Short-term studies have shown improvements in postural control following surgery, but the long-term impact remains unclear.

Methods: This single-center prospective cohort study included adult patients undergoing long-segment fusion surgery between November 2019 and July 2021. Preoperative and postoperative balance assessments, radiographic analyses, and patient-reported outcome measures (PROMs) were conducted. Statistical analyses evaluated changes in postural stability and clinical outcomes.

Results: Fifteen ASD patients were analyzed. Significant improvements were observed in the early postoperative period in coronal center of pressure (COP) sway (P=0.048) and amplitude (P=0.027), total COP sway (P=0.042), coronal center of gravity (COG) amplitude (P=0.013), total COG sway (P=0.044), and head sway in the coronal plane (P=0.025). These improvements were maintained at the final postoperative visit for all measurements except coronal COG amplitude (early vs. last postoperative visit, P=0.040). Radiographic parameters, including pelvic incidence - lumbar lordosis mismatch (P=0.041) and sagittal vertical axis (P=0.032), also significantly improved postoperatively. PROMs revealed significant enhancements in VAS back pain (P=0.045), RAND SF-36 pain (P=0.016), RAND SF-36 physical functioning (P=0.008), and PROMIS pain interference (P=0.032) scores at the last follow-up.

Conclusion: These results demonstrate that the postural stability improvements seen after ASD correction are durable and correlate with enhanced clinical outcomes, such as reduced back pain and improved physical functioning. These findings underscore the clinical importance of achieving sagittal alignment in ASD patients. Further research with larger cohorts and extended follow-up periods is warranted to confirm these associations and establish postural stability assessment as a vital parameter in evaluating patients' quality of life postoperatively.

Level of evidence: Level 3.