Sagittal Alignment of the Spine in Patients with Adult Spinal Deformity

Abstract

Adult spinal deformity (ASD) is common spinal disorder in the elderly. The feature of spinal alignment in ASD patients is loss of lumbar lordosis, which results in a forward leaning posture. Sagittal imbalance has been shown to correlate with poor health related QOL especially concerning upright standing and walking. Past studies have been conducted to understand ideal sagittal global alignment, and some formulas have been developed to calculate the ideal lumbar lordosis matching pelvic incidence, which assists in surgical planning when deciding the amount of correction. To evaluate the individual spinal deformity in the sagittal plane, understanding the presence of compensatory mechanisms is indispensable. The basic mechanisms of sagittal compensation are extension of the neighboring flexible spine or backward rotation of the pelvis to avoid anterior translation of the gravity line. Global evaluation of the entire spine and pelvis including compensatory mechanisms allows for better planning for surgical management of these patients. This paper provides an overview of the sagittal spinal parameters which concern the diagnosis and treatment of patients with ASD, and describes a therapeutic solution for future ASD care.