The Re-Evaluation of Frailty in Predicting Complications after Long-Segment Spinal Fusion for Adult Spinal Deformity.

Objective: To evaluate on a national scale how frailty status (stratified using the 5-item Modified Frailty Index (mFI-5)) affects the operative characteristics of and complications after long-segment spinal fusion (LSF) for adult spinal deformity (ASD).

Methods: Adults undergoing LSF of ≥3 vertebrae in the National Surgical Quality Improvement Program database years 2015-2020 were split into 2 cohorts: nonfrail with mFI = 0 or 1; frail with mFI ≥2. Demographics, operative characteristics, and 30-day complications were contrasted between the cohorts using the Student's t-test, the Fisher's exact test, or a multivariate analysis when appropriate.

Results: In the 340 LSF cases collected, 268 fell into the nonfrail cohort and 72 into the frail cohort. The frail cohort constituted a high rate of geriatric age (65.3% vs. 38.1%; P < 0.001), higher body mass index (32.9 ± 0.86 vs. 30.2 ± 0.39; P = 0.005), and more comorbidities in 9 of 14 measures. After surgery, the frail cohort experienced more urinary tract infections (odds ratio [OR], 3.33; confidence interval [CI], 1.01-10.94; P = 0.04). However, the frail cohort shared similarities with the nonfrail cohort in terms of length of stay (5.11 ± 0.51 vs. 6.01 ± 1.62 days; P = 0.60), home discharge (OR, 0.76; CI, 0.42-1.39; P = 0.38), readmission (OR, 2.45; CI, 0.87-6.89; P = 0.09), and overall rate of complications (OR, 0.89; CI, 0.50-1.59; P = 0.70).

Conclusions: Despite trends found in past studies of ASD, this analysis showed that the frailty status of mFI ≥2 is a poor predictor of surgical and hospitalization course and overall complications in LSF when examined up to 30 days postoperatively.