Is there a difference in unilateral versus bilateral facetectomy in an open or MIS TLIF? A systematic review and meta-analysis

Introduction: To compare radiological, operative, and clinical outcomes of a unilateral versus bilateral facetectomy for the transforaminal lumbar interbody fusion (TLIF) utilizing an open approach or minimally invasive surgery (MIS).

Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a comprehensive search of research databases yielded 9 clinical cohort studies that explicitly compared unilateral versus bilateral facetectomy for TLIF for degenerative lumbar pathology: 2 open-only, 6 MIS-only, and 1 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 MIS-only and combined groups but not reported in open-only articles. In MIS-only publications, bilateral facetectomy was associated with higher operative blood loss, postoperative drain output, and surgical duration. One open-only publication reported that bilateral facetectomy experienced statistically significantly greater ΔPHQ-9 (-4.6±5.2 vs -0.8±4.6, p=0.03) and ΔQALY (0.3±0.2 vs 0.1±0.2, p=0.01). One MIS-only publication reported that unilateral facetectomy incurred significantly greater ΔODI-2yrs (25.8±23.5 vs 8.2±29.6, p=0.026) while bilateral facetectomy had a greater ΔPROMIS-PF-2yrs (13.7±4.4 vs 3.7±4.0).

Conclusion : Regardless of surgical technique, unilateral facetectomy is comparable to bilateral facetectomy with respect to radiologic, operative, and clinical outcomes. The unilateral approach in MIS TLIF has the added benefit of decreased blood loss, operative time, and drain output, while these parameters were not specifically compared in the open-only TLIF studies. The role of a unilateral facetectomy for standard lumbar degeneration is an acceptable and favorable approach, which is particularly valuable in MIS TLIFs wherein a single facet is commonly exposed.