Overlay of Nerve Roots to Aid in Augmented Reality–Guided L4 to L5 Transforaminal Interbody Fusion: A Methodologic Pilot

<sec><title>Background</title> Minimally invasive transfacet transforaminal lumbar interbody fusion (TF-TLIF) offers advantages over open approaches, including reduced tissue disruption and faster recovery. However, limited visualization increases the risk of neural injury, particularly to the exiting nerve roots and thecal sac. </sec><sec><title>Innovation</title> This case report illustrates the integration of augmented reality (AR) to enhance real-time visualization during TF-TLIF. A 53-year-old man with symptomatic L4 to L5 spondylolisthesis underwent AR-assisted TF-TLIF. Preoperative imaging included magnetic resonance imaging, computed tomography, and advanced neurography sequences (Multi-Echo iN Steady-state Acquisition, Short Tau Inversion Recovery, and Dixon T1), which were used to generate a 3D model of critical anatomy. A safe transfacet trajectory was planned preoperatively and overlaid onto the surgical field through the operative microscope, using intraoperative 3D imaging for registration. Intraoperative neurophysiological monitoring complemented visual guidance. </sec><sec><title>Clinical Relevance</title> AR enabled continuous visualization of neural structures during drilling, discectomy, and cage placement. The patient had no complications and was discharged on postoperative day 1 without new neurological deficits. While limited to a single case, this report demonstrates the feasibility of AR-assisted TF-TLIF. This technology may serve as a promising adjunct in minimally invasive spine surgery. Further studies are needed to assess the impact on efficiency and outcomes. </sec><sec><title>Level of Evidence</title> 4. </sec>