Left versus Right-sided Approach for Prone Lateral Interbody Fusions in a Cohort Study of 146 Consecutive Patients

Introduction: Prone lateral interbody fusion is a single-position retroperitoneal transpsoas method to reconstruct the anterior column of the spine. While access can be achieved from either the left or right side, there is a notable lack of studies examining the right-sided approach. This study aims to compare operative outcomes of left- and right-sided approaches to prone lateral interbody fusions.

Methods: We conducted a multi-centre, single-surgeon cohort study involving all consecutive patients who underwent prone lateral interbody fusion from 2022 to 2024. Demographic, intra-operative, and post-operative outcomes data were collected, with patients categorized into left- or right-sided prone lateral interbody fusions. Descriptive analysis was performed on the cohort to identify any differences in outcomes between the two approaches.

Results: In total, 146 prone lateral interbody fusions were completed (L=70, R=76), which included 84 females and 62 males (mean age 70 years; mean BMI 28.6). There were no statistically significant differences between cohorts for mean anaesthetic time (L=214min, R=217min), total operative time (L=151min, R=150min), lateral operative time (L=45min, R=50min), psoas retraction times (L=17min, R=17min), or average blood loss (L=88ml, R=64ml). Intra-operatively, there were 11 neuromonitoring alerts (L=7 (4.7%), R=4 (2.7%)). Among these, one patient reported residual psoas symptoms at three months follow-up, and one left-sided L4/5 fusion was converted to a right-sided approach to accommodate neural anatomy. Post-operatively, one periprosthetic infection, one periprosthetic malposition or fracture requiring reoperation, and one anterior longitudinal ligament release for both left and right approaches resulted in a cumulative complication rate of 4.1%.

Conclusion : The study demonstrates that the lumbar spine can be effectively accessed from both left- and right-sided approaches for prone lateral interbody fusions. The reported outcomes enhance our understanding of the procedure's operative results and safety profile from either side, challenging the conventionally preferred left-sided approach for this technique.