Modifiable Uncontrolled Frailty (mFI-5) in Lumbar Fusion Outcomes.

STUDY

DESIGN

Retrospective Cohort.

OBJECTIVE

To investigate impact of controlled/uncontrolled sub-stratification of modified frailty index (MFI-5) on postoperative outcomes after lumbar fusion for degenerative disease.

BACKGROUND

mFI-5 outperforms age as a predictor of postoperative risk. Sub-stratification of mFI-5 by controlled versus uncontrolled frailty has allowed for better risk prognostication in spinal deformity cases.

METHODS

Adult patients who underwent elective, single-level lumbar fusion (2017-2021) were identified. Fusions for infection/trauma/tumor/revision were excluded. Patients were classified as frail/non-frail based on having any mFI-5 criteria (history of chronic obstructive pulmonary disease [COPD], congestive heart failure [CHF], diabetes mellitus [DM], hypertension [HTN] requiring medication, and functional status). Frailty was considered controlled unless patients had a COPD exacerbation within 3 months prior to surgery, preoperative hemoglobin A1c >7, or HTN ≥140/90 mmHg for ≥2 visits.

RESULTS

1,286 patients were included (controlled/uncontrolled/non-frail-804/159/323). Uncontrolled frailty patients had more 31-90 day ED visits (9.43% vs. 4.13%,P=0.009), 0-30 day readmissions (5.66% vs. 2.49%,P=0.042), and renal complications (13.2% vs. 6.38%,P=0.005) compared to controlled frailty patients. Controlled frailty patients were older (56.3 vs. 62.9, P<0.001) and had more 0-30 day ED visits (2.19% vs. 5.63%,P=0.021) compared to non-frail patients. Uncontrolled frailty patients were older (56.3 vs. 63.8,P<0.001), and had higher 0-30 (2.19% vs. 7.55%,P=0.010) and 31-90 day ED visits (1.88% vs. 9.43%,P<0.001), 0-30 day readmissions (0.93% vs. 5.66%,P=0.003), and renal complications (3.76% vs. 13.2%,P<0.001) compared to non-frail patients. Multivariable regression demonstrated that uncontrolled frailty alone was independently associated with 30-day ED visits (odds ratio [OR]-3.68,P=0.030), any ED visit (OR-3.33,P=0.008), 90-day readmission (OR-5.42,P=0.047) and any readmission (OR-5.41,P=0.005).

CONCLUSION

Multivariable regression demonstrated that uncontrolled frailty was an independent risk factor for ED visits and readmission after single-level lumbar fusion. Further work is needed to identify the best pre- and postoperative strategies to optimize outcomes for this vulnerable population.