Hovering Technique with Direct Visualization and Dynamic Retraction during Lateral Lumbar Interbody Fusions

Introduction: Lumbar Interbody Fusions (LIF) have become a widespread technique in addressing the lumbar spine for spinal conditions such as spondylolisthesis, degenerative pathologies, and disc herniations. The Lateral Lumbar Interbody Fusion (LLIF) approach, which involves fixed retraction of the psoas muscle, poses a new set of possible complications that must be accounted for. With this in mind, we propose a modification to LLIF surgeries to further reduce their commonly cited complications. This includes a hovering technique above the level of the psoas, as well as dynamic retraction to access the disc space. The goal of this modification is to reduce immediate postoperative motor and sensory complications.

Methods: This was a single-institution, retrospective analysis of patients undergoing a modified LLIF procedure. A standard LLIF technique was performed with the exception that a retractor was placed above the level of the psoas, allowing direct visualization of the psoas, and dynamic retraction was utilized to enter and visualize the disc space. Data was abstracted from Electronic Health Records and included basic patient characteristics, number of levels, posterior instrumentation, and any new postoperative complications.

Results: Amongst 53 patients, 76 levels were done using the modified LLIF technique, with level breakdowns as follows: T12-L1: 3, L1-L2: 14, L2-L3: 30, L3-L4: 27, L4-L5: 2. The overall modified LLIF complication rate was 3.9%. 0% denoted a motor complication, and 3.9% indicated a sensory complication of anterior thigh numbness. Anterior thigh numbness improved in all three cases within 3 months.

Conclusion : Modified techniques involving docking above the psoas and dynamic retraction hold promise to reduce complications when performing Lateral Lumbar Interbody Fusions. Results from our cohort demonstrated fewer motor and sensory complications when compared to the literature-reported values. Further studies are needed to further evaluate and monitor this novel technique's efficacy and complication profile.