The 5-Factor Modified Frailty Index is Associated With Increased Risk of Reoperations and Adjacent Level Disease Following Single-Level Transforaminal Lumbar Interbody Fusion

Abstract

Study Design Retrospective Cohort Study. Objectives To determine the predictive capability between the 5-factor modified frailty index (mFI-5) scores and adverse clinical and radiographic outcomes following single-level transforaminal lumbar interbody fusion (TLIF). Methods All patients over the age of 50 undergoing single-level open or minimally invasive TLIF from 2012 to 2021 with a minimum follow-up of 1 year were identified. Deformity, trauma, emergency, and tumor cases were excluded as were patients undergoing revision surgeries. An mFI-5 score was computed for each patient using a set of five factors which included hypertension requiring medication, chronic obstructive pulmonary disease, diabetes mellitus, congestive heart failure, and partially or fully dependent functional status. Univariate and multivariate logistic regression analysis were performed to evaluate the impact of mFI-5 scores on readmissions, reoperations, and postoperative complications. Results 156 patients were included and grouped according to their level of frailty: no-frailty (mFI = 0, n = 67), mild frailty (mFI = 1, n = 59), and severe frailty (mFI = 2+, n = 30). Multivariate analysis found high levels of frailty (mFI = 2+) to be independent predictors of reoperation (OR: 16.9, CI: 2.7 - 106.9, P = .003) and related readmissions (OR = 16.5, CI: 2.6 - 102.7, P = .003) as compared to the no-frailty group. An mFI-5 score of 2+ was also predictive of any complication (OR = 4.5, CI: 1.4 - 14.3, P = .01) and adjacent segment disease (ASD) (OR = 12.5, CI: 1.2 - 134.0, P = .037). Conclusion High levels of frailty were predictive of related readmissions, reoperations, any complications, and ASD in older adult patients undergoing single-level TLIF.