Objective:

To compare outcomes between minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and anterior lumbar interbody fusion (ALIF) at L5/S1.

Methods:

Primary, elective, single, MIS-TLIF or ALIF with posterior fixation at L5/S1 were identified. Patient-reported outcome measures (PROMs) were collected. Coarsened exact matching was used to control for significant differences. Achievement of Minimum Clinical Important Difference [MCID] was determined by comparing ΔPROM scores to threshold values. Demographic/perioperative characteristics were compared between MIS-TLIF and ALIF cohorts using chi-squared and Student’s t-tests.. Differences in mean PROM scores, MCID rates, , and postoperative complications were evaluated using unpaired t-test.

Results:

Following coarsened exact matching, 93 patients received MIS-TLIF and 50 received ALIF. Cohorts differed in operative time, estimated blood loss (EBL), and postoperative narcotic consumption on POD 0 (p<0.034, all). . Mean PROMs differed significantly at: SF-12 PCS 6-weeks, and 1-year, PROMIS-PF 6-weeks, ODI 6-weeks, and VAS back 6-weeks with ALIF cohort demonstrating significantly improved mean PROMs (p ≤ 0.044, all). Significantly greater rates of MCID achievement for PROMS for the ALIF cohort: VAS back 6-weeks, ODI 12 weeks, SF-12 PCS 6-weeks, and PROMIS-PF 12-weeks (p ≤ 0.047, all). Greater rate of MCID achievement for MIS-TLIF cohort were seen for 6-week and overall VAS leg (p<0.046, all) Postoperative fever was greater in TLIF cohort (9.6% vs 2.0%, p<0.047).

Conclusion:

ALIF patients demonstrated significantly improved rates of MCID achievement for disability, physical function, and back pain during early postoperative period. However, overall MCID achievement rate for leg pain was higher for MIS-TLIF cohort.