The Impact of Osteoporosis on Patient Presentation in the Adult Spinal Deformity Population

Introduction: Osteoporosis is commonly comorbid with adult spinal deformity (ASD), a cyclical relationship in which each condition may synergistically contribute to the severity of patients’ clinical presentation. We hope to investigate osteoporosis’s role in a patient’s preoperative presentation.

Methods: Operative ASD patients with complete preoperative baseline (BL) were included. Osteoporosis defined as an existing diagnosis of osteoporosis at BL. High risk defined as female ≥ 65Y based on American Association of Clinical Endocrinologist definitions. Alignment was assessed using the Global Alignment and Proportionality (GAP) score and the Sagittal Age Adjusted Score (SAAS). HRQLs: ODI, SF-36, and SRS-22r. ODI stratified by disability severity into quintiles. The three cohorts, osteoporotic (O), high risk (HR), and non-osteoporotic (NO), were characterized via descriptive statistics and means comparison analyses to understand group differences and multivariate logistic regression to assess risk factors while adjusting for appropriate covariates.

Results: 899 patients included: age 60.3±15.0Y, 74%F, BMI 27.5±5.8kg/m2, CCI 1.7±1.7. Cohort composition: O 165 (18.4%), HR 194 (21.6%), NO 540 (60.1%). O had worse quality of life at BL in the following: ODI (50 v 43, p<.001), SF-36 PCS (28 v 32, p<.001), SRS activity (2.66 v 2.90, p=.022), pain (2.26 v 2.43, p=.032), appearance (2.25 v 2.44, p=.006), and total (2.63 v 2.79, p=.005).
When adjusting for BL age, BMI, gender, CCI, and mFI, HR/O were significantly less likely to be SAAS-matched at BL (OR: .646, p=.038). When adjusting for BMI, CCI, and mFI, HR/O were significantly less likely to be GAP-proportioned at BL (OR: .485, p=.003). When adjusting for those GAP proportioned and SAAS-matched at BL, HR/O were more likely to be severely disabled (ODI>60) (OR: 1.45, p=.041).

Conclusion : Osteoporosis affects ASD patients in many domains. These patients suffer from a poorer quality of life, have higher comorbidity burdens, and present with more severe deformity.