A Narrative Review of Uniportal Endoscopic Lumbar Interbody Fusion: Comparison of Uniportal Facet-Preserving Trans-Kambin Endoscopic Fusion and Uniportal Facet-Sacrificing Posterolateral Transforaminal Lumbar Interbody Fusion

Illustration of uniportal facet-sacrificing posterolateral endoscopic fusion. (A) Oblique view of the lumbar spine model shows left L4/5 uniportal facet-sacrificing posterolateral transforaminal lumbar interbody fusion. Note that the blue facet joint was removed to gain access to the disc space. (B) Axial view shows left L4/5 uniportal facet-sacrificing posterolateral transforaminal lumbar interbody fusion. Note the blue facetectomy and extension into the disc space, demonstrating the working corridor and access in the uniportal facet-sacrificing posterolateral transforaminal lumbar interbody fusion approach. (C) Oblique magnified view of the lumbar spine shows left L4/5 extended Kambin’s triangle in blue, which is subtended by the exiting nerve root as the hypotenuse, the traversing nerve root as the opposite side, and the proximal vertebral end plate of the caudal vertebral body as the adjacent side. This anatomical corridor is a natural window of safe access to the disc, with no significant neurovascular structures within the triangle. The size of the extended Kambin’s triangle is less dependent on the pathology of the facet joint. It is bigger in lower lumbar segments than in upper lumbar segments.

Intraoperative fluoroscopic pictures of uniportal facet-preserving trans-Kambin endoscopic fusion. (A) The working cannula of the transforaminal endoscope is docked in Kambin’s triangle directly on the disc space. Foraminoplasty is optional, depending on the size of Kambin’s triangle and the presence of exiting nerve root irritation. (B) 8-mm dilation with cannula inserted. (C) 10-mm dilation with open square cannula inserted. (D) Lateral fluoroscopic view of the open square cage glider. (E) Anteroposterior view of the expandable cage inserted under the protection of an open cage glider. Figure reproduced with permission from Sairyo K, Morimoto M, Yamashita Y, et al. Full-endoscopic trans-Kambin’s triangle lumbar interbody fusion: technique and review of literature. J Minim Invasive Spine Surg Tech. 2021;6(Suppl 1):S123-S129.

Intraoperative fluoroscopic pictures of uniportal facet-sacrificing posterolateral transforaminal lumbar interbody fusion. (A) Lateral fluoroscopic view of the Harrison cage glider put in place with the tip of the cage glider in the posterior third of the disc space. The cage glider protects the traversing and exiting nerve root. (B) Anteroposterior fluoroscopic view of the Harrison cage glider with the tip positioned in the medial and lateral parts of the disc space, protecting the traversing and exiting nerve root. (C) Lateral fluoroscopic view of the interbody cage being inserted through the Harrison cage glider.

Pre- and postoperative X-ray for single-level L3/4 uniportal facet-preserving trans-Kambin endoscopic fusion performed on an 84-year-old female who presented with L3/4 spondylolisthesis and L3/4 foraminal stenosis with back and leg pain. (A,B) Preoperative anteroposterior and lateral views of the patient showing the retrolisthesis of L3 on L4 and foraminal stenosis. (C,D) Corresponding postoperative anteroposterior and lateral views of the patient showing restoration of disc height with expansion of foraminal dimension and correction of the retrolisthesis to a neutral position.