Assessment of a Novel Adult Cervical Deformity Frailty Index as a Component of Preoperative Risk Stratification

Objective: To determine the value of a novel adult cervical deformity frailty index (CD-FI) in preoperative risk stratification.

Methods: We reviewed a prospective, multicenter database of adults with cervical spine deformity. We selected 40 variables to construct the CD-FI using a validated method. Patients were categorized as not frail (NF) (<0.2), frail (0.2-0.4), or severely frail (SF) (>0.4) according to CD-FI score. We performed multivariate logistic regression to determine the relationships between CD-FI score and incidence of complications, length of hospital stay, and discharge disposition.

Results: Of 61 patients enrolled from 2009 to 2015 with at least 1 year of follow-up, the mean CD-FI score was 0.26 (range 0.25-0.59). Seventeen patients were categorized as NF, 34 as frail, and 10 as SF. The incidence of major complications increased with greater frailty, with a gamma correlation coefficient of 0.25 (asymptotic standard error, 0.22). The odds of having a major complication were greater for frail patients (odds ratio 4.4; 95% confidence interval 0.6-32) and SF patients (odds ratio 43; 95% confidence interval 2.7-684) compared with NF patients. Greater frailty was associated with a greater incidence of medical complications and had a gamma correlation coefficient of 0.30 (asymptotic standard error, 0.26). Surgical complications, discharge disposition, and length of hospital stay did not correlate significantly with frailty.

Conclusions: Greater frailty was associated with greater risk of major complications for patients undergoing cervical spine deformity surgery. The CD-FI may be used to improve the accuracy of preoperative risk stratification and allow for adequate patient counseling.