Research Fellow Hospital for Special Surgery Hospital for Special Surgery
Introduction: Frailty is defined as a state of minimal “physiologic reserve.” The modified 5 factor frailty index (mFI-5) is a recently proposed metric for assessing frailty and has been previously studied as a predictor of morbidity and mortality. However, its utility in predicting postoperative patient reported outcomes (PROMs) and return to activities remains understudied. The purpose of the present study is to provide more granular data on longer term patient outcomes in frail patients defined with the mFI-5 index following one- or two-level MI-TLIF for the treatment of degenerative lumbar disorders. Specifically, we aim to 1) study the relationship between PROMs and mFI-5 and 2) evaluate whether mFI-5 influences recovery kinetics.
Methods: This is a retrospective cohort study of patients undergoing 1 or 2 level minimally invasive transforaminal lumbar interbody fusion queried from a prospectively maintained multi-surgeon registry. Comorbidities including hypertension, congestive heart failure, diabetes, chronic obstructive pulmonary disease, and functional status were utilized to calculate the mFI-5. Patients were separated into 3 cohorts, “non-frail,” “moderately frail” or “severely frail” based on their mFI-5. Patient outcomes were compared between the cohorts.
Results: 392 patients were included of which 227 patients were non-frail, 134 were moderately frail, and 31 were severely frail. Frail patients had longer operative time (p=0.002), greater estimated blood loss (p=0.038). Despite similar preoperative PROMs, at a longer term follow up, frail patients also had worse PROM scores for ODI (p=0.009), VAS-back (p=0.028), and VAS-leg (p=0.004). Frail patients had worse preoperative (p=0.017) and postoperative (p < 0.001) SF-12 PCS. At 1-year, frail patients had lower rates of fusion (p=0.002). Frail patients also demonstrated lower rates of returning to work (p=0.018), returning to driving (p=0.027), and discontinuation of narcotics (p=0.004).
Conclusion : Frail patients as measured by the mFI-5 index demonstrated worse postoperative outcomes following 1 or 2 level MI-TLIF. Careful patient selection and preoperative optimization may be especially important in frail patients.