Lumbar interbody fusions are designed to structurally remove pathologic disks to replace it with an interbody spacer. Recent interests in minimally invasive surgeries (MIS) and its reported short-term advantages have led to a paradigm shift towards minimally invasive posterior interbody fusion approaches. Evidence of long-term advantages, however, has been lacking. This review compares long-term outcomes of conventional open versus minimally invasive posterior lumbar interbody fusion.

A Literature search was done in the PubMed gateway of the MEDLINE database and Google Scholar from the time of inception until September 2022. Outcome measures include long-term pain scores, functional outcome scores, complication incidences, and total treatment costs. Review Manager 5.4 was used for data analysis. A total of 10 articles were included for quantitative and qualitative analysis. There were no significant differences in the overall visual analog scale (VAS) scores between minimally invasive surgery (MIS) and open surgery (OS). Subgroup analysis of the back and leg pain also failed to demonstrate a significant difference between the two groups. Consequently, no significant differences were seen in the functional outcomes between the two groups. The incidence of long-term complications was significantly lower in the MIS group compared with the OS group, with an overall risk ratio of 0.59, 95% CI [0.37, 0.94]. Subgroup analysis also showed a significantly lower incidence of adjacent segment pathology (ASP) in the MIS group (Risk ratio 0.47, 95% CI [0.25, 0.87]). However, the two groups had no significant difference in the revision surgery. Lastly, no significant difference was demonstrated in the total costs between the two groups.

The long-term pain, functional, and cost outcomes of conventional OS and MIS posterior lumbar interbody fusion surgery are comparable. However, there is a lower overall complication rate, specifically ASP, in patients undergoing minimally invasive posterior lumbar interbody fusion surgery.