Disparities in Recovery and Survival Rates in Cervical versus Thoracolumbar Spinal Deformity Patients Are Attributable to Frailty Status at Presentation

Introduction: Previous studies have demonstrated relatively higher risk of death in CD surgeries, yet there remains a paucity of literature comparing and contrasting the comorbidities and predictive factors associated with death in ASD vs CD surgery.

Methods: Operative ASD and CD patients ≥18yrs with pre-(BL) and (5Y) data were included. Group differences were assessed via means comparison analysis. Backstep logistic regression identified mortality predictors. Kaplan-Meier analysis assessed survivorship of expired patients. Lpg rank analysis determined differences in survival distribution groups.

Results: 161 total patients were included (99 ASD, 83 CD). Within 5Y, 12 ASD patients (12.1% of ASD cohort) and 16 CD patients (19.3% of CD cohort) expired (p=0.004). At baseline, ASD and CD patients differed significantly in BL Frailty score (0.29 vs 0.41, p < .001), though not in age, gender, nor BMI (all p>.05). The most common comorbidities in ASD patients were: arthritis (46%), hypertension (31%), and anemia (23%); in CD patients: osteoporosis (50%), previous myocardial infarction (17%), and any cancer (17%). No significant differences in major nor intraoperative complications between living or expired ASD or CD patients were observed (all p>.05), though ASD patients did experience more minor surgical complications overall (p=.017). Accounting for age, BMI, and gender, regression revealed only frailty status remained a significant predictor of death overall between cohorts(p=.047). Further regression analysis revealed Mean survival time for ASD was 84.11 weeks versus 65.17 in CD patients (p=.387).

Conclusion : Total two-year all-cause mortality in adult spinal deformity and cervical deformity patients remains below 3% despite high rates of comorbidities, suggesting rigorous selection criteria plays an important role in maintaining the safety of such surgeries. This study demonstrates that while cervical deformity patients demonstrate greater incidence of death post-operatively, significantly increased baseline frailty status may be the principal cause of such results and should be considered when assessing surgical risks versus benefits.