Study design:

Retrospective cohort study.

Objective:

The objective of this study was to compare the incidence of surgical site infection (SSI) after lateral lumbar interbody fusion (LLIF) and posterior/transforaminal lumbar interbody fusion (P/TLIF).

Summary of background data:

Previous studies have shown that LLIF can improve neurological symptoms to a comparable degree to P/TLIF. However, data on the risk of SSI after LLIF is lacking compared with P/TLIF.

Methods:

The study was conducted under a retrospective cohort design in patients undergoing LLIF or P/TLIF for lumbar degenerative diseases between 2013-2020 using a hospital administrative database. We used propensity score overlap weighting to adjust for confounding factors including age, sex, body mass index, comorbidities, number of fusion levels, hospital size, and surgery year. We estimated weighted odds ratios (ORs) and 95% confidence intervals (CIs) for SSI within 30 days postoperatively.

Results:

27,119 patients (2,874 in the LLIF group and 24,245 in the P/TLIF group) were included in this study. Compared with P/TLIF, LLIF was associated with a significantly lower risk of SSI (0.7% vs. 1.2%; weighted OR, 0.57; 95% CI, 0.36-0.92; P=0.02).

Conclusions:

In this large retrospective cohort study of adults undergoing lumbar interbody fusion, LLIF was associated with a significantly lower risk of SSI than P/TLIF. The small, but significantly, decreased risk of SSI associated with LLIF may inform decisions regarding the technical approach for lumbar interbody fusion.We compared the risk of SSI between 2,874 patients who underwent LLIF and 24,245 patients who received P/TLIFPatients who had received LLIF were significantly less risk of experiencing an SSI compared with those receiving P/TLIF (0.7% vs. 1.2%; weighted OR, 0.57; 95% CI, 0.36-0.92; P=0.02).As a secondary outcome, patients who had received LLIF had less risk of transfusion (7.8% vs. 11.8%; weighted OR, 0.63; 95% CI, 0.54-0.73; P<0.001).