Objective:

To identify perioperative predictors of minimum clinically important difference (MCID) for patients undergoing lateral lumbar interbody fusion (LLIF) for the patient-reported outcome measures (PROMs) of Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS-PF), Visual Analog Scale (VAS) Back, VAS Leg, Oswestry Disability Index (ODI), and Patient Health Questionnaire-9 (PHQ-9).

Methods:

Patients undergoing LLIF were identified through retrospective review of a single-surgeon database. Overall MCID achievement was determined as the number of unique patients achieving ΔPROM thresholds of PROMIS-PF=4.5, VAS Back=2.1, VAS Leg=2.8, ODI=14.9, and PHQ-9=3.0 over a 2-year postoperative time period. Univariate and multivariable logistic regression were utilized to determine perioperative predictors for MCID achievement.

Results:

Two-hundred and ninety patients were identified. For PROMIS-PF MCID achievement, increased preoperative PROMIS-PF and POD 1 VAS pain were significant negative predictors. For VAS Back, primary fusion with revision decompression was a negative predictor, while increased preoperative VAS Back was a positive predictor of MCID achievement. For VAS Leg, increased preoperative VAS Leg was a positive predictor. For ODI, increased POD 0 VAS pain was a negative predictor, while increased preoperative ODI was a positive predictor. For PHQ-9, increased preoperative PHQ-9 was a positive predictor.

Conclusion:

In patients undergoing LLIF, perioperative predictors for MCID achievement were highly dependent on PROM. Preoperative PROM was the most consistent perioperative predictor for achieving MCID. Elevated acute postoperative pain and primary fusion after failed index decompression were significant predictors of failing to achieve MCID. Surgeons may use these findings in prognostication and management of postoperative expectations.