The Use of Dual Direction Expandable Titanium Cage With Biportal Endoscopic Transforaminal Lumbar Interbody Fusion: A Technical Consideration With Preliminary Results

Neurospine Neurospine 2023;20(1):110-118. https://doi.org/10.14245/ns.2346116.058 Original Article Corresponding Author Dong Hwa Heo https://orcid.org/0000-0003-1203-4550 Department of Neurosurgery, Endoscopic Spine Surgery Center, Champodonamu Hospital, 32 Baumoe-ro 35-gil, Seocho-gu, Seoul 06744, Korea Email: Received: January 25, 2023 Revised: February 27, 2023 Accepted: February 27, 2023 pISSN 2586-6583 eISSN 2586-6591 The Use of Dual Direction Expandable Titanium Cage With Biportal Endoscopic Transforaminal Lumbar Interbody Fusion: A Technical Consideration With Preliminary Results Don Young Park1, Dong Hwa Heo2 Department of Orthopaedic Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA Department of Neurosurgery, Spine Center, Champodonamu Spine Hospital, Seoul, Korea 1 2 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (https://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Copyright © 2023 by the Korean Spinal Neurosurgery Society Objective: Expandable cage technology has emerged for lumbar interbody fusion to restore intervertebral disc space height and alignment through a narrow surgical corridor. The purpose of this study is to present the technique of biportal endoscopic transforaminal lumbar interbody fusion (TLIF) using dual direction expandable cage and provide early clinical results. Methods: We performed the biportal endoscopic TLIF using a dual direction expandable titanium cage for height restoration and a larger footprint in 10 patients. Clinical parameters including Oswestry Disability Index (ODI), visual analogue scale (VAS), and complications were retrospectively analyzed. Also, we investigated radiologic parameters using preoperative and postoperative x-ray images. Results: We successfully inserted dual direction expandable cages during biportal endoscopic TLIF. There was no significant subsidence or collapse of the expandable cages during the 6-month follow-up period. Lumbar lordosis and disc height were significantly increased after surgery. ODI and VAS scores were significantly improved at 6 months after surgery. Conclusion: In this report, we describe the first use of a dual direction expandable interbody TLIF cage that expands in both width and height in biportal endoscopic TLIF surgery. Early clinical and radiographic outcomes of this TLIF technique may be favorable in early 6-month follow-up. Keywords: Endoscopy, Lumbar vertebrae, Surgery, Biportal INTRODUCTION Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) has demonstrated comparable clinical outcomes and safety profile as compared to open conventional TLIF with significant improvement of pain and disability.1,2 More recently, endoscopic techniques to perform TLIF surgery have been introduced with similar success as MIS-TLIF, especially with biportal endoscopic techniques.3-8 The biportal endoscopic TLIF 110 www.e-neurospine.org technique is similar to the MIS-TLIF technique in that the technique utilizes a posterolateral interlaminar approach, while visualizing the spinal anatomy with an endoscopic camera.7-9 Thr ough the technique, direct decompression of the spinal canal can be achieved and interbody fusion can be completed through a transforaminal approach. This allows for restoration of intervertebral disc height and reduction of the spondylolisthesis, which has demonstrated significant correlation with clinical success.10,11 The biportal endoscopic technique is less invasive as compared Park DY, et al. Dual Expandable Cage With Biportal Endoscopic Fusion to other MIS techniques with preservation of the lumbar musculoligamentous structures, which may reduce postoperative pain and facilitate recovery.5,7,8,12 Expandable cage technology has been developed for interbody fusion and has demonstrated the ability to restore intervertebral disc height and correct alignment.13,14 However, subsidence of the vertebral endplates is a significant concern, especially with point loading of a narrow cage within the center of the intervertebral disc space.15,16 A narrow cage is typically utilized for a TLIF approach due to the narrow corridor available within the neural foramen to introduce the implant. With subsidence, collapse of disc height, loss of reduction, and malalignment may occur, which can lead to suboptimal clinical outcomes. Recently, a novel dual direction expandable titanium TLIF cage has been developed that expands both in the medial to lateral dimension and in height. The cage can be placed through the neural foramen in the narrow, collapsed state. Once in the disc space, the medial to lateral expansion increases the surface area of endplate bony contact and provides contact with the apophyseal rings, which has been shown to be the strongest portion of the vertebral endplate.17,18 With these advantages, complete expansion with this dual expandable cage may lead to less subsidence and restore lumbar lordosis. The purpose of this study is to present the technique of biportal endoscopic TLIF utilizing the dual direction expandable titanium TLIF cage and provide preliminary results. (Dual-X TLIF, Amplify Surgical, Inc., Irvine, CA, USA) in this study (Fig. 1). The design of this study was a retrospective analysis of prospectively collected data with description of surgical technique. After obtaining Institutional Review Board (IRB) approval from the hospital where the author was affiliated (IRB approval No. CA-TR-1), the investigations was performed. The design of this study was a technical report with preliminary data. The indications of this TLIF technique included degenerative spondylolisthesis, lumbar central stenosis, Lumbar foraminal stenosis and isthmic spondylolisthesis. We excluded the revision surgery, infection, trauma, and multilevel disease. Only patients who had full clinical and radiographic data for at least 6 months after surgery were included in the study. We analyzed clinical data including Oswestry Disability Index (ODI), visual analogue scale (VAS) of back and leg, operation time, estimated blood loss, and complications. Estimated blood loss included postoperative blood drainage amount. We obtained lumbar radiographs, including anteriorposterior (AP) and lateral x-rays including flexion and extension lateral views preoperatively, immediately postoperatively and 6 months after surgery. We measured disc height of operative segment (anterior height+posterior height/2), segmental lordotic angle of operative level, and lumbar lordotic angle using preoperative and postoperative x-rays. Significant cage subsidence was defined as a cage invading the vertebral body by more than 2 mm. Subsidence and collapse of the expandable cages were evaluated by disc height measurement. Since the patient sample was small, nonparam (...truncated)