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Int J Surg Case Rep
Int J Surg Case Rep
International Journal of Surgery Case Reports
2210-2612
Elsevier

S2210-2612(24)00967-2
10.1016/j.ijscr.2024.110186
110186
Case Report
The biportal endoscopic posterior open-door laminoplasty with the use of mini-plate for cervical spondylotic myelopathy: Case report and literature review
Gong Zhiyuan gzy19900811@zju.edu.cn
a
Jing Xiaowei docjingxw@zju.edu.cn
b
Qiu Xiaowen qiuxiaowen@zju.edu.cn
b
Ping Zichuan orthen_ping@zju.edu.cn
b
Hu Qingfeng huqingfeng@zju.edu.cn
b⁎
a Department of Nursing, The Fourth Affiliated Hospital of Zhejiang University School of Medicine, China
b Department of Orthopedic Surgery, The Fourth Affiliated Hospital of Zhejiang University School of Medicine, N1 Shangcheng Road, Yiwu, Zhejiang, China
⁎ Corresponding author. huqingfeng@zju.edu.cn
15 8 2024
10 2024
15 8 2024
123 11018610 7 2024
11 8 2024
14 8 2024
© 2024 The Authors
2024
https://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Introduction

Biportal endoscopy, a newly developed technique rapidly applied in lumbar spine surgery, has recently been utilized for treating cervical spine diseases. We present a case of cervical spondylotic myelopathy managed with open-door laminoplasty fixed by mini-plate and performed with biportal endoscopy assistance.

Presentation of case

The patient, a 62-year-old woman, presented with gradually developing weakness in the lower extremities. CT and MR images showed cervical stenosis at C4–5 and C5–6. We performed a posterior open-door laminoplasty using biportal endoscopy assisted by a mini-plate. After completing the gutters on both sides of the hinge and open-door, we detached the spinous process from the lamina through endoscopic-guided burr grinding. The skin incisions of the portals on the open-door side were connected for direct fixation of the elevated lamina with a mini-plate. There was improvement in ambulatory capacity for the patient along with radiological evidence of decompressed cervical canal.

Discussion

Endoscopic technology is increasingly employed in spinal surgery, with several studies documenting the utilization of biportal endoscopic techniques to facilitate open-door laminoplasty procedures for managing myelopathic cervical spondylosis. The procedures we report allow for safer and more efficient placement of the mini-plate that prevents door re-closing.

Conclusions

The potential applications of biportal endoscopic technology in open-door cervical spine surgery are worth considering, given the soft tissue damage caused by traditional posterior cervical spine surgery. However, the safety and effectiveness of this method still require more studies with a larger number of cases and longer follow-up to be substantiated.

Highlights

• We performed open-door posterior cervical surgery with biportal endoscopy assistance.

• The mini-plate was utilized to secure the lamina on the open-door side, thereby preventing the door from closing again.

• We connect the incisions of the viewing and working portals together in order to facilitate the placement of mini-plates.

Keywords

Biportal endoscope
Open-door
Laminoplasty
mini-plate
Cervical myelopathy
Case report
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pmc1 Introduction

The expansive open-door laminoplasty (EOLP) technique is widely accepted for managing multilevel cervical spondylotic myelopathy (CSM) resulting from various causes, such as disc herniation, ossification of the posterior longitudinal ligament (OPLL), hypertrophic ligamentum flavum, and congenital cervical spinal stenosis. This technique has been used since 1977 [1].

Several techniques have been documented for open-door laminoplasty, which have been shown to effectively promote neurological recovery while preserving specific posterior structures and segmental motion in the cervical spine compared to multilevel laminectomy [2]. However, complications including postoperative axial symptoms, C5 nerve palsy, implant failure, and lamina reclosure have been reported [3]. This surgical approach requires careful dissection of deep paraspinal muscles and removal of ligamentous structures, which is often associated with the development of axial symptoms [4].

The technique of unilateral biportal endoscopy/biportal endoscopic spinal surgery (UBE/BESS) was first proposed and reported by De Antoni in 1996 [5]. Compared to uniportal system, the biportal system offers greater flexibility as observation and operation do not interfere with each other. Under the consistent exploration and research of spine surgeon, the application of the technique has been continuously expanded to various spinal-related diseases and satisfactory clinical results have been achieved [6].

Recently, innovative laminoplasty techniques that aim to preserve paravertebral muscles have been described by several spinal surgeons and resulted in favorable clinical outcomes [7,8]. Additionally, biportal endoscopy-guided open-door laminoplasty with mini-plate fixation has been performed to minimize damage to paravertebral muscles and achieve promising clinical outcomes [9]. To optimize the safeguarding of the musculoskeletal structures encompassing the posterior aspect of the cervical spine, we investigated the application of biportal endoscopy-guided open-door laminoplasty with mini-plate fixation for managing cervical CSM.

2 Case presentation

2.1 History and examination

The patient, a 62-year-old woman, presented with insidious and gradual onset of motor weakness in the lower extremities. Physical examination revealed no decrease in tactile, pain, or temperature sensation in the extremities. Muscle strength was decreased, particularly in hand grasp and knee extension (Medical Research Council classification grade 4), without muscle atrophy. Deep tendon reflexes in the extremities exhibited an exaggerated response. A positive Hoffmann sign was observed in the left hand, while bilateral Babinski sign was negative. The Japanese Orthopedic Association (JOA) score was recorded as 10. Past medical history included hypertension, hypertensive heart disease, and type 2 diabetes. Computed Tomography (CT) imaging detected osteophytes at C4–5 and C5–6 intervertebral space levels (Fig. 1A–C). Magnetic resonance imaging (MRI) revealed cervical stenosis at C4–5 and C5–6 due to disc protrusion and ligamentum flavum hypertrophy (Fig. 1D–F). The patient perceived a greater severity of the injury and declined to undergo traditional posterior open surgery. We performed posterior open-door laminoplasty of C5 and C6 with assistance from the biportal endoscopy system.Fig. 1 Findings on CT and MR images. A, Sagittal CT image. B, Axial CT image of C4–5. C, Axial CT image of C5–6. D, Sagittal T2-weighted MR image. E, Axial T2-weighted MR image of C4–5. F, Axial T2-weighted MR image of C5–6.

Fig. 1

2.2 Surgical procedure

The patient, under general anesthesia, was positioned in the prone (face-down) orientation on a spinal surgery table with head support provided by a Mayfield headstock. Neurophysiological monitoring techniques, specifically motor evoked potentials (MEP) and somatosensory evoked potentials (SSEP), were employed. Two horizontal lines delineated the upper and lower boundaries of the surgical segment's bilateral masses. Additionally, a vertical line was drawn adjacent to the lateral edge of the right lateral mass, while another vertical line marked the medial margin of the left pedicle (Fig. 2A and B). Intersection points A and D were designated as working portals, whereas points B and C served as observation portals. The right side acted as the hinge side, while the left side was referred to as the open-door side. To identify both the surgical segment and puncture site accurately, a C-arm imaging device was utilized to mark these locations on the patient's skin (Fig. 2C). Subsequently, puncturing of portals commenced followed by progressive enlargement using tubes of varying sizes (Fig. 2D–H).Fig. 2 Locating the portals. A and B, Illustration of the portal positions on the anteroposterior and lateral X-ray images. Two horizontal lines were drawn along the upper edge of the bilateral masses of C5 and the lower edge of C6 lateral masses. A vertical line was positioned along the lateral margin of the right lateral mass, while another vertical line was drawn along the lateral margin of the left pedicle of C5 and C6. The intersections of these lines served as the locations for portals a, b, c, and d. C, Depicts the skin location of the surgical segments and the respective portals. D, E, F, G, H, Illustrate the process of puncturing and creating the portals.

Fig. 2

The subsequent procedure was conducted with the guidance of endoscopy. Firstly, the bone hinge was prepared to elevate the lamina on the right side of the patient. At this stage, radio frequency (RF) was utilized to dissect the muscles, exposing the lamina and lateral mass and creating an appropriate space for manipulation. A 2 mm diamond burr was employed to abrade the bony gutter until reaching the inner layer cortex (Fig. 3A). Subsequently, both endoscope and instruments were relocated to the left side of the patient. Similar to the left side, exposure of lamina, base of spinous process, and lateral mass took place. The junction between spinous process and lamina was ground through using a 3 mm diamond burr (Fig. 3D, E, F). Then, a complete layer gutter at the junction between lamina and lateral mass was created using a burr and a 1 mm Kerrison rongeur (Fig. 3B, C).Fig. 3 Endoscopy images. A, The gutter of the hinge side. B and C, The gutter on the open-door side. D, a: the junction of the spinous process and lamina. b: the inferior edge of the lamina. c: the inferior edge of the spinous process. E. Drill the left cortex at the junction of the spinous process and lamina. F, Drill through the right cortex at the junction of the spinous process and lamina. e: The left lamina. d: The right lamina.

Fig. 3

The following steps will be performed visually. A skin incision connecting portal C and D was made while paravertebral muscles were bluntly separated. Two right-angle retractors were employed to pull back muscles in order to expose left lamina's gutter. By means of a 2 mm Kerrison rongeur, elevation of lamina from left to right side occurred. Once there is sufficient gap size achieved, an assistant on opposite side used a curved hook for lifting assistance while controlled fracture on hinge side with one flip motion took place for laminar elevation purposes. Finally secured fixation in position by employing titanium mini-plate along with screws under direct visualization followed by insertion of drainage tube on open-door side; sutures were used for closure completion. A step-by-step flowchart was made to aid in visualizing the procedure (Fig. 4).Fig. 4 The flowchart of the surgery procedure.

Fig. 4

2.3 Postoperative management, clinical outcome and follow-up

After the surgical procedure, prophylactic antibiotics were administered for a duration of 24 h, and the drainage tube was removed 48 h postoperatively. Furthermore, it was recommended that the patient wear a postoperative semi-rigid cervical collar for a period of one month. The upper limb muscle strength demonstrated a significant improvement, reaching grade 5. The JOA score increased from 10 preoperatively to 14 on the third day after surgery, reaching a value of 15 at one-year follow-up. The patient reported no pain or stiffness in the neck and shoulders. CT and MRI scans demonstrated cervical canal enlargement and successful spinal cord decompression (Fig. 5A–C). The CT scan conducted after one year revealed osseous healing at the hinge side gutter area, consistent with fusion between vertebral laminae and spinous processes (Fig. 5D–G). This work has been reported in line with the SCARE criteria [10].Fig. 5 Postoperative CT and MR images. A, Sagittal T2-weighted MR image. B, Axial T2-weighted MR image of C5. C, Axial T2-weighted MR image of C6. D, Axial CT image of C5 3 days after surgery. E, Axial CT image of C6 3 days after surgery. F, Axial CT image of C5 one year after surgery. G, Axial CT image of C5 one year after surgery. H, surgical incision.

Fig. 5

3 Discussion

Expansive open-door laminoplasty is a commonly employed technique for the treatment of cervical spondylotic myelopathy. This approach effectively widens the spinal canal, preserves cervical spine mobility, and yields favorable clinical outcomes as demonstrated by medium- to long-term follow-up studies [11]. Indeed, damages to the posterior elements, such as the severing of the supraspinous ligament and detachment of paraspinal muscles, can lead to the development of axial symptoms and progressive kyphosis [12]. Modified laminoplasty techniques that focus on preserving or reconstructing the attachment of deep cervical paravertebral muscles have demonstrated a reduction in axial pain and improved clinical outcomes compared to traditional procedures. In light of the increasing use of spinal endoscopy in lumbar spine surgeries, attempts have been made to apply percutaneous endoscopy for the treatment of cervical spondylotic myelopathy. In microscopic and percutaneous endoscopic surgery, the approach of unilateral laminotomy for bilateral decompression of the cervical spine typically results in less substantial spinal enlargement when compared to open-door laminoplasty. Additionally, this technique often requires more intraspinal manipulation, which in turn increases the risk of spinal cord injury. This risk is particularly heightened when there is compression of the ventral spinal cord due to issues like intervertebral disc problems or ossification of the OPLL [[13], [14], [15]].

The use of the UBE technique has been applied in the treatment of degenerative lumbar spine conditions, including herniated discs, spinal stenosis, and spondylolisthesis [16]. In cervical spine surgery, this technique allows for foraminoplasty and discectomy to treat cervical radiculopathy [[17], [18], [19]]. Some notable cases include Kim's report on a patient with cervical spondylotic myelopathy who underwent unilateral laminotomy with bilateral decompression using biportal endoscopy [20]. Zhu has used bilateral biportal endoscopic open-door laminoplasty with suture anchors fixation in a patient with cervical stenosis. Nevertheless, there have been concerns about lamina reclosure during follow-up [21,22]. Kim placed the mini-plate through the working portal under the biportal endoscopy guidance, which we believe it is difficult and more likely to damage the spinal cord [23].

Under the guidance of endoscopy, the surgical procedure begins by creating a bony gutter that preserves the ventral cortical bone on the hinge side, all under the guidance of endoscopy (Fig. 6A). Subsequently, the junction between the spinous process and lamina is carefully ground through, starting from the left side and progressing to the right side (Fig. 6B), followed by the preparation of the gutter on the open side. The most challenging part of the entire procedure is to elevate the lamina on the open side and keep the door open using a mini-plate. To facilitate this, the spinous process is separated from the lamina through a 3-mm grinding process, creating sufficient space for laminar elevation while avoiding obstruction from the spinous process and its associated ligaments (Fig. 6C). The lamina is elevated using a 2 mm Kerrison forceps and secured in place with the assistance of a curved hook. The mini-plate is carefully positioned and inserted between the lamina and the lateral mass (Fig. 6D). Indeed, considering the difficulty of placing the plate through the portal, we took a different way than Kim. Our approach involves connecting the portals on the open side and gently separating the muscle to expose the lamina and lateral mass after the gutters have been prepared. Following this, the lamina is elevated using Kerrison forceps, and the mini-plate is positioned through the open surgical approach. This technique helps ensure a smoother and more precise placement of the mini-plate during the procedure. The endoscopic procedures were described with a video (Supplemental video).

During this procedure, surgeons must be mindful of several critical points. It is crucial to expose only the inner half of the bilateral lateral mass, as excessive exposure can result in bleeding and hinder visibility under endoscopy. Additionally, adequate separation between the spinous process and lamina using a drill of 3 mm or larger is essential to prevent obstruction during the lamina elevation process. Moreover, it is imperative to perform the procedure prior to creating gutters on the open side in order to avoid any iatrogenic injury to the spinal cord. The amount of bleeding after grinding through the lamina on the open-door side was comparatively lower than that observed in open surgery. Possible reasons may include the application of water pressure and a more precise removal technique for the inner layer of the vertebral plate, ensuring minimal damage to the underlying intraspinal veins under endoscopic guidance. Moreover, in order to prevent potential formation of epidural hematoma that could lead to compression of the spinal cord, insertion of a drainage tube can be considered as a cautious measure to ensure patient safety. The process of bone healing in the spine's laminae and spinous processes was observed during the follow-up period, while ensuring better preservation of the posterior structure.Fig. 6 Schematic of the surgery procedures. A, Drill the outer cortex of the hinge side gutter. B, Drill through the junction of the spinous process and lamina. C, Drill the full cortex of the open-door side gutter. D, Elevate the lamina and fix it with the mini-plate.

Fig. 6

However, the described technique has some limitations. This surgical approach demands a more extended learning curve and should ideally be undertaken by seasoned surgeons and well-trained assistants. The most challenging step is precisely placing the small steel plate. Initially, we tried positioning it from the working portal; however, this proved to be difficult. Subsequently, we chose a connecting portal incision similar to the paracentral incision, which allowed for direct visualization and easier insertion of the small steel plate. The patients involved in this study primarily underwent decompression for two segments, which necessitates further investigation into the feasibility and safety of applying this technique to cases involving more segments. This case report is limited in scope, and a larger patients group results are imperative to comprehensively assess the safety and efficacy of this procedure.

4 Conclusion

Posterior cervical laminoplasty is an effective surgical approach for treating myelopathic cervical spondylosis. However, postoperative axial pain is a common complication associated with damage to the posterior ligament complex and paraspinal muscles. We achieved favorable clinical outcomes of cervical spinal cord decompression using an endoscopic-assisted open-door laminoplasty procedure. This technique can preserve the ligamentum flavum complex and paraspinal muscles behind the cervical spine.

The following are the supplementary data related to this article.Supplementary video 1

Grinding the gutters of the open-door side and the hinge side, depart the spinous process from lamina.

Supplementary video 1

Consent

Written informed consent was obtained from the patient for publication and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.

Ethical approval

The Ethics Committee of our department does not require ethics review for case reports of medical procedures performed within the normal scope of care, if written consent is obtained from the individual patient.

Funding

No.

Guarantor

Hu Qingfeng.

CRediT authorship contribution statement

Gong Zhiyuan: writing the paper

Hu Qingfeng: study concept, design and performed for surgery

Jing Xiaowei: data collection,

Qiu Xiaowen: make figures and illustrations

Zichuan Ping: article correcting.

Declaration of competing interest

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Acknowledgements

We appreciate the help of our colleagues at the Department of Orthopedic Surgery, the fourth affiliated hospital of Zhejiang University School of Medicine. The authors also express their sincere gratitude to the patient reported in this study.
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