Background: Transforaminal lumbar interbody fusion (TLIF) is widely used to treat degenerative spinal pathologies. However, deciding whether to use a unilateral or bilateral facetectomy has historically been based on surgeon preference. This study aims to compare radiological, operative, and clinical outcomes of unilateral versus bilateral facetectomy in open or minimally invasive surgery (MIS) TLIF. Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, nine cohort studies were identified: two open-only, six MIS-only, and one combined MIS-open TLIF publications. Forest plots generated a pooled analysis for each outcome measure. Results: Meta-analyses found no difference in lumbar lordosis between facetectomy procedures in open-only, MIS-only, or combined groups. Disc height change was similar in the MIS-only and combined groups. In MIS-only publications, bilateral facetectomy was associated with higher blood loss, postoperative drainage, and surgical duration. One open-only publication reported that bilateral facetectomy experienced statistically significantly greater delta patient health questionnaire-9 (−4.6 ± 5.2 vs. −0.8 ± 4.6, P = 0.03) and quality-adjusted life year (0.3 ± 0.2 vs. 0.1 ± 0.2, P = 0.01). One MIS-only publication reported that unilateral facetectomy incurred significantly greater delta Oswestry disability index after 2 years (25.8 ± 23.5 vs. 8.2 ± 29.6, P = 0.026) while bilateral facetectomy had a greater delta patient-reported outcomes measurement information system-physical function scale after 2 years (13.7 ± 4.4 vs. 3.7 ± 4.0). Conclusion: Unilateral and bilateral facetectomy produce comparable radiologic, operative, and clinical outcomes. In MIS TLIF, unilateral facetectomy offers reduced blood loss, operative time, and drainage. Unilateral facetectomy is an acceptable and potentially favorable option for standard lumbar degeneration, particularly in MIS TLIF, where exposure is limited to a facet.
Tcheukado et al. (2026) studied this question.