Clinical Observation of Posterior Percutaneous Full-Endoscopic Cervical Foraminotomy as a Treatment for Osseous Foraminal Stenosis

Accepted Manuscript Clinical Observation of Posterior Percutaneous Full-Endoscopic Cervical Foraminotomy as a Treatment for Osseous Foraminal Stenosis Zhi-Yuan Ye, MD, Wei-Jun Kong, MD, Zhi-Jun Xin, MD, Qiang Fu, MD, Jun Ao, MD, Guang-Ru Cao, MD, Yu-Qiang Cai, MD, Wen-Bo Liao, MD PII:

S1878-8750(17)31185-3

DOI:

10.1016/j.wneu.2017.07.085

Reference:

WNEU 6147

To appear in:

World Neurosurgery

Received Date: 15 May 2017 Revised Date:

15 July 2017

Accepted Date: 15 July 2017

Please cite this article as: Ye Z-Y, Kong W-J, Xin Z-J, Fu Q, Ao J, Cao G-R, Cai Y-Q, Liao W-B, Clinical Observation of Posterior Percutaneous Full-Endoscopic Cervical Foraminotomy as a Treatment for Osseous Foraminal Stenosis, World Neurosurgery (2017), doi: 10.1016/j.wneu.2017.07.085. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

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TITLE PAGE

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Clinical Observation of Posterior Percutaneous Full-Endoscopic Cervical Foraminotomy as

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a Treatment for Osseous Foraminal Stenosis

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Zhi-Yuan Ye, MD1, Wei-Jun Kong, MD1, Zhi-Jun Xin, MD1, Qiang Fu, MD2, Jun Ao, MD1,

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Guang-Ru Cao, MD1, Yu-Qiang Cai, MD1, Wen-Bo Liao, MD*

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Co-author: 1 Department of Spine Surgery, The Affiliated Hospital of Zun Yi Medical College,

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No. 121 Da Lian Road District Hui Chuan, Zun Yi, 563000, China

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Provincial People's Hospital, School of Medicine, University of Electronic Science and

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Technology of China, Cheng du, Si chuan, 610072, P.R. China.

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*Corresponding author: Wen-Bo Liao, MD, Department Head of Spine Surgery, The Affiliated

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Hospital of Zun Yi Medical College, No. 121 Da Lian Road District Hui Chuan, Zun Yi, 563000,

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China

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Telephone number: 86-13985685360

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E-mail Number: [email protected]

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Fax Number: 0851-28622043

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Institute of Organ Transplantation, Sichuan Academy of Medical Sciences and Sichuan

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Keywords: cervical posterior foraminotomy, minimally invasive spine surgery, osseous

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foraminal stenosis, percutaneous full-endoscopic, radicular root syndromes.

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Abbreviations:

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CT: computed tomography

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MISS: minimally invasive spine surgery

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MRI: magnetic resonance imaging

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MTPF: microscopic tubular retractor-assisted posterior foraminotomy

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NDI: neck disability index

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P-FECD: posterior percutaneous full-endoscopic cervical foraminotomy and discectomy

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P-PECF: posterior percutaneous full-endoscopic cervical foraminotomy

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VAS: visual analogue scale

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ABSTRACT

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Objective: To observe the clinical effects of posterior percutaneous full-endoscopic cervical

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foraminotomy in patients with osseous foraminal stenosis.

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Methods: Nine patients with osseous foraminal stenosis underwent surgery using the posterior

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percutaneous full-endoscopic cervical foraminotomy technique and received follow-up care for 1

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year. The visual analogue scale (VAS) score, neck disability index (NDI), and modified Macnab

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criteria were recorded at the last follow-up. All patients underwent three-dimensional computed

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tomography (CT) of the cervical spine, which was reviewed within 1 week postoperatively.

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Results: All operations were successful, and all patients received follow-up care. The mean

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operation time was 80 min. Surgical bleeding was not observed, and no related complications

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occurred. Postoperative VAS and NDI scores were significantly reduced compared with the

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preoperative assessment. Additionally, imaging showed that the osteophytes in the intervertebral

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foramen were adequately resected. According to modified Macnab criteria, 6 cases showed

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excellent results, 3 cases showed good results, and no fine or bad results were observed.

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Conclusions: Posterior percutaneous full-endoscopic cervical foraminotomy can accomplish full

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nerve root decompression and is a safe, feasible procedure. Therefore, it can be a treatment

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option for patients with osseous foraminal stenosis.

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INTRODUCTION Cervical radicular root syndrome was first described by Semmes and Murphey in 1943, and Murphey provided an additional description in 1973. Radicular symptoms are well known to

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typically arise due to a lateral disc herniation or osteophytes in the intervertebral foramen.

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Surgical decompression may become necessary if conservative therapeutic measures fail or if

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paralysis is present. Various surgical approaches can be used to treat cervical radiculopathy,

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including posterior and anterior procedures.1,2 In 1944, a study by Spurling and Scoville showed

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that posterior cervical foraminotomy was a safe and effective treatment for cervical spondylotic

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radiculopathy, including for patients with osseous foraminal stenosis.3-5 Thereafter, Frykholm

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further modified the procedure.6 Due to the development of minimally invasive spine surgery

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(MISS) and the cervical endoscopic system, MISS technology has become increasingly utilized

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by surgeons because it minimizes trauma, and patients experience a faster recovery.7-9 In 2008,

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Rutten et al. reported the use of full-endoscopic cervical posterior foraminotomy for lateral disc

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herniations and obtained effective clinical results.10,11 In 2016, Oertel et al.12 reported the use of

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an endoscopic posterior cervical foraminotomy to treat osseous foraminal stenosis, which was

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performed using tubular retractor-assisted procedure and applied microsurgical techniques.

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Furthermore, endoscopy was applied to achieve better illumination and an enlarged view of the

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surgical field.12 However, a detailed description of the posterior percutaneous full-endoscopic

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cervical foraminotomy (P-PECF) technique only for cervical osseous foraminal stenosis is not

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currently available in the related literature. In contrast to other operation techniques, the posterior

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full-endoscopic approach is performed under direct visualization on a monitor and with

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continuous fluid flow with 0.9% saline solution.13 In addition, an endoscopic lighting system is

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applied to improve the clarity of the visual field. Moreover, the skin incision is 6.9 mm, and

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surgical trauma is markedly reduced.

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Beginning in 2015, we performed the P-PECF technique in 9 patients with only osseous foraminal stenosis and excluded patients with lateral disc herniation. The aim of the present

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study was to report clinical and functional outcomes in P-PECF patients after at least a year of

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follow-up care.

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Patient Characteristics

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In this study, we enrolled 9 patients with osseous foraminal stenosis who underwent a P-PECF in 2015 including 6 male and 3 female patients whose ages ranged from 39 to 56 years

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(mean, 46 years). The duration of pain ranged from 15 days to 6 months (mean, 120 days). Seven

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patients had received conservative treatment for a mean of 3 months, and two patients were

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unable to tolerate the pain and required surgery. The indication for surgery was intolerable

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radicular pain or neurologic deficits. Two interventions were performed at the C4-5 level, 5

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interventions were performed at the C5-6 level, and 2 interventions were performed at the C6-7

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level (Table 1).

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Inclusion Criteria

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The following were indications for foraminotomy: unilateral radiculopathy with arm pain, preoperative imaging diagnosis revealing an osseous foraminal stenosis and without cervical disc

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herniation (Fig. 1), unsuccessful strict conservative treatment for more than 3 months, or

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inability to tolerate the pain.

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Patients with clear instabilities or deformities were excluded. Lateral and medial

localization of disc herniation was an absolute exclusion criterion. Patients with two-level or

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three-level osseous foraminal stenosis and patients with bilateral symptoms were not included in

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the study.

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Operative Technique

All patients were placed in the prone position and received general anaesthesia. The head

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was fixed in place with tape, and the cervical spine was adjusted on the table in a slightly flexed

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and high-low position. The arms were placed in a caudal position relative to the body with the

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application of gentle tension. The affected segment was identified using lateral fluoroscopy.

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Positive lateral radiography was used to determine and locate the posterior part of the facet joint.

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Routine disinfection of the surgical area was performed with sterile surgical towels and aseptic

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dressings. Under the guidance of the C-arm, the medial edge of the articular facet joint was

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confirmed by needle puncture (Fig. 2). After a skin incision of 6.9 mm was made above the

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medial junction of the inferior and superior facet joint, an obturator (6.9 mm outer diameter) was

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introduced. The tip of the obturator was placed at the marked point under fluoroscopic guidance.

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The back wall of the nerve root canal and the medial margin of the facet joint were palpated with

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the obturator. The oblique-type working channel was introduced on the obturator, and the

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endoscope was introduced (Fig. 3). The operation was performed under a continuous flow of

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0.9% saline solution, which was placed approximately 1 m above the head of the operating table.

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The osteophytes in the intervertebral foramen and the compressed nerve root were viewed

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through the endoscope. Each step must be performed carefully, and the safety of the operation

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should be checked with the probe before each step. We used 3-mm drills and bone punches to

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resect the bone at the medial joint segment. In order to prevent nerve root injury, high speed drill

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must be directed toward the lateral edge of the facet joint (Fig. 4). When the hyperplastic bone is

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polished to a very thin extent, we can remove the thin bone with a probe and a rongeur. The

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excision of soft tissue from around the nerve root be carefully performed, and the soft tissue and

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nerve root should be separated by the probe (video 1). When the intervertebral foramen was

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enlarged and the nerve root was decompressed (Fig. 5), the endoscopic operation system was

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removed and the skin was directly closed. No drainage was required. All patients were given a

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soft brace for 7 days.

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Endoscopic Instruments

The spinal endoscopy system (SPINENDOS Co, Munich, Germany) comprised a 4.3 mm

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working channel, an outer sheath with a 6.9 mm diameter, a 30°-angled scope with a continuous

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water irrigation system and a low-temperature radiofrequency ablation system (ArthroCare Co,

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California, USA). The drill was made by NOUVAG AG, a Swiss company.

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Follow-up Care

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Follow-up examinations were conducted at 1, 3, 6 and 12 months after surgery. The

clinical efficacy and possible complications were observed and recorded. All patients received a

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questionnaire and follow-up examinations at the clinic. The examination consisted of radiologic

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findings, a neurological examination, and pain scoring for the upper arm and neck using a visual

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analogue scale (VAS) and the neck disability index (NDI) score. The clinical outcomes were

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evaluated using the modified Macnab criteria. All patients underwent a postoperative computed

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tomography (CT) scan, which was performed 1 week after the operation.

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RESULTS

All 9 operations were performed in patients with unilateral symptoms and single-level

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stenosis. The operation time was approximately 75-100 min, with an average duration of 80 min.

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There was no severe bleeding. All patients underwent a foraminotomy and expansion of the

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nerve root canal. The nerve root was exposed and decompressed, which included performing a

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partial facetectomy. After the operation, decompression was confirmed using CT scans in all

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patients. The postoperative hospital stay was 2-3 days (mean, 2.7 days). The symptoms were

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relieved after the operation, and no complications such as nerve injury occurred. The clinical

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outcomes are described in Table 2. The VAS score of the upper limb and neck and the NDI score

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were significantly improved (p<0.0001) compared with the preoperative scores. The differences

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at postoperative 12 months versus 1 month were also statistically significant (p<0.05) (Fig. 6).

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According to the modified Macnab criteria (Table 3), the clinical efficacy was excellent in 7

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cases and good in 2 cases; no cases were rated as fine or bad after 12 months of follow-up care.

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A bony channel and enlargement of the intervertebral foramen were observed in the

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postoperative CT scans of the cervical spine (Fig. 7). All 9 patients received follow-up care for at

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least 1 year. No emergencies occurred during the surgeries that required switching to open

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procedures. One patient had transient hypaesthesia; the sensory deficits were completely

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reversible within 1 week after surgery. No other intraoperative or postoperative complications,

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such as haematoma, root injury, or wound infection, occurred.

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DISCUSSION

Bony stenosis of the cervical intervertebral foramen, which is caused by the degeneration

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of the cervical spine, often leads to serious consequences. Reasons for intervertebral foramen

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osseous stenosis include bone hyperplasia of the hook vertebral joint, abnormal joint position,

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joint bone hyperplasia and narrowing of the intervertebral space. Surgical decompression may

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become necessary if conservative therapeutic measures fail. Traditional surgical techniques for

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decompression of the cervical spine include open anterior and open posterior approaches.1,2 The

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anterior approach represents the gold standard for decompression of the cervical spine; however,

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the anterior approach is associated with vascular injuries, nerve injury and other related

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complications.14 The open posterior approach can also produce better clinical results; however,

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this approach can cause neck pain, muscle cramps and dysfunction and even lead to serious

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disability and other risks.7,15,16 In recent years, surgeons have continued to explore the effect of

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beneficial, small-trauma surgery. Due to the development of MISS, surgeons are able to focus on

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the diagnosis and minimally invasive treatment of spinal nerve root entrapment syndrome.

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Posterior minimally invasive surgery has developed rapidly and has achieved clinical results that

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are comparable to open surgery.17 In terms of surgical trauma, intraoperative bleeding,

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postoperative recovery, duration of hospital stay, and other variables, the minimally invasive

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approach has an obvious advantage.18 Current related studies report that the cervical posterior

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minimally invasive approach is mainly used in patients with cervical laterally located soft disc

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herniation.19 The procedures mainly include posterior percutaneous full-endoscopic cervical

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foraminotomy and discectomy (P-FECD)13,20 and tubular retractor-assisted posterior

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foraminotomy and discectomy (MTPF).21 In 2009, Kim performed a comparison between the

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open procedure and the tubular retractor-assisted procedure for cervical radiculopathy.8 The

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results of the randomized controlled study showed no obvious difference in the clinical effects of

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the two types of surgery. However, the minimally invasive surgery resulted in less trauma and a

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faster recovery. This type of surgery has obvious advantages regarding the incision length, length

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of stay, and use of early analgesics. Additionally, this type of surgery can avoid complications

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such as neck pain and muscle spasms that are caused by open surgery. In 2015, Kim et al.

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reported a comparison of the clinical effects of two types of minimally invasive surgery for the

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treatment of cervical lateral disc herniation.20 The results showed that both types of surgery

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achieved good clinical results. However, the NDI and VAS scores were lower after the

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percutaneous full-endoscopic procedure than after the tubular retractor-assisted procedure.

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Additionally, the reoperation rate was lower after P-PECD. In the same year, Kim et al. reported

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changes in cervical sagittal alignment after single-level posterior percutaneous full-endoscopic

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cervical discectomy.13 The study showed that cervical lordosis had not worsened for patients

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with lordosis >10° and had improved for patients with lordosis <10°. After 2 years of follow-up

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care, the cervical curvature, disc height, and segmental angle had not worsened. Related studies

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report that using posterior minimally invasive cervical foraminotomy as a treatment for cervical

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lateral disc herniation can result in better clinical outcomes. This minimally invasive procedure

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has several advantages over its open surgery counterpart, as it is associated with less trauma, less

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bleeding, faster recovery, and a shorter hospital stay.8,9 However, few studies have examined the

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use of an endoscopic technique as a treatment for osseous foraminal stenosis.7,22-24 In 2016,

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Oertel et al.12 reported the clinical results of endoscopic posterior cervical foraminotomy to treat

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osseous foraminal stenosis, which required the use of tubular retractor-assisted and applied

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microsurgical techniques.12 The operation was safe and effective for the treatment of osseous

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foraminal stenosis. Additionally, the study suggested that the clinical success rate was lower and

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the reoperation rate was higher in patients suffering from osseous foraminal stenosis than in

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patients suffering from lateral disc herniation. The application of the P-PECF technique for the

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treatment of osseous foraminal stenosis is not well reported in the literature.

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The aim of the present study was to report short-term clinical results after P-PECF for

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patients with single-level and unilateral osseous foraminal stenosis. The entire procedure was

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performed under direct visualization on a monitor and with the continuous flow of 0.9% saline.

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Nerve electrophysiology monitoring was applied during the operation. The operations went

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smoothly in all 9 patients. With the exception of 1 patient who experienced transient

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hypaesthesia, no other intraoperative or postoperative complications, such as haematoma, root

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injury or wound infection occurred.11,25,26 The upper limb pain and numbness symptoms of the

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patients were abated, the VAS score and the NDI score decreased significantly, and the modified

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Macnab results were satisfactory after 1 year of follow-up care. The clinical results were

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consistent with results of previous reports in the literature.10-12,20

The reasons for intervertebral foramen osseous stenosis mainly include bone hyperplasia of

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the hook vertebral joint and joint bone hyperplasia. Surgical decompression might become

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necessary if conservative therapeutic measures fail. The operation performed in this study

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involved a posterior cervical foraminotomy approach. In general, resection of bony hyperplasia

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in front of the cervical foramen, such as bone hyperplasia of the hook vertebral joint, is not

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necessary. However, in cases of serious bone hyperplasia of the hook vertebral joint, surgical

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removal of the hyperplastic bone is required. Therefore, osseous point resection is not necessary

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for all patients. We did not subdivide the axillar and shoulder approach in our operation. The

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osseous point arises from a location axillar to the nerve root is mainly constituted by bone

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hyperplasia of the hook vertebral joint. If the bone hyperplasia of the hook vertebral joint is very

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serious, we will adopt an axillar surgical approach. Nerve electrophysiology monitoring was

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applied to observe the intraoperative nerve roots. Each step must be performed carefully, and the

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safety of the operation should be checked with the probe before each step. In order to prevent

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nerve root injury, high speed drill must be directed toward the lateral edge of the facet joint. The

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excision of soft tissue from around the nerve root must be carefully performed, and the soft

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tissue and nerve root should be separated by the probe. The soft tissue must not be torn blindly to

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avoid injury to the nerve root.

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Patients with lateral disc herniation were not included in the study. Patients with clear instabilities or deformities were excluded. The study only included patients suffering from osseous foraminal stenosis. The surgical indications for this procedure are still relatively limited.

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With the development of this technique, we will continue to study the indications to better select

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cases and achieve the desired results. We will also further attempt to expand the surgical

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indications for two-level or even three-level osseous foraminal stenosis.

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In contrast to microscopic procedure, which also gives very good results in cervical foraminal stenoses, the P-PECF procedure is performed under direct visualization on a monitor

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and with continuous fluid flow with 0.9% saline solution. In addition, an endoscopic lighting

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system is applied to improve the clarity of the visual field. Moreover, the skin incision is 6.9 mm,

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and surgical trauma is markedly reduced. Overall, the P-PECF procedure has several advantages,

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including a short operation time, fast recovery, less trauma, shorter hospital stay, low cost, less

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bleeding, and maintained mobility of the patient. However, the following disadvantages exist: a

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limited possibility of expanding the operation in the event of unforeseen hindrances, indication

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limitations, and a high learning curve.11 Additionally, there may be postoperative complications

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such as haematoma, root injury, wound infection and instability of the cervical spine. Therefore,

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the surgeon should be skilled in the operation of full-endoscopic system technology and should

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undergo strict minimally invasive technology training to overcome problems and complications

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encountered when performing full-endoscopic procedures. During the procedure, the surgeon

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should refrain from pulling the nerve beyond its limitations to avoid nerve injury. The

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application of nerve electrophysiology monitoring during the operation is necessary. We also

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maintain that before receiving training for the posterior cervical endoscopic system, one should

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be fully familiar with and have a flexible grasp of the full-endoscopic technique of the lumbar

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spine.

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The number of cases selected for this study was small, and the short-term follow-up period for evaluation of the operation induces limitations. The procedure can be more accurately

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evaluated following the development of surgical techniques, selection of more cases to increase

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the sample size, as well as an expansion of the follow-up period, long-term follow-up imaging

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and long-term clinical effects.

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CONCLUSIONS The P-PECF procedure can accomplish full nerve decompression and is therefore an effective treatment for patients with osseous foraminal stenosis.

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Rodrigues MA, Hanel RA, Prevedello DM, Antoniuk A, Araujo JC. Posterior approach for soft cervical disc herniation: a neglected technique? Surg Neurol. 2001;55:17-22. Smith GW, Robinson RA. The treatment of certain cervical-spine disorders by anterior removal of the intervertebral disc and interbody fusion. J Bone Joint Surg Am. 1958;40-A:607-624. Caglar YS, Bozkurt M, Kahilogullari G, Tuna H, Bakir A, Torun F, et al. Keyhole approach for posterior cervical discectomy: experience on 84 patients. Minim Invasive Neurosurg. 2007;50:7-11. Ducker TB, Zeidman SM. The posterior operative approach for cervical radiculopathy. Neurosurg Clin N Am. 1993;4:61-74. Henderson CM, Hennessy RG, Shuey HM, Jr., Shackelford EG. Posterior-lateral foraminotomy as an exclusive operative technique for cervical radiculopathy: a review of 846 consecutively operated cases. Neurosurgery. 1983;13:504-512. Frykholm R. Lower cervical vertebrae and intervertebral discs; surgical anatomy and pathology. Acta Chir Scand. 1951;101:345-359. Fessler RG, Khoo LT. Minimally invasive cervical microendoscopic foraminotomy: an initial clinical experience. Neurosurgery. 2002;51:S37-45. Kim KT, Kim YB. Comparison between open procedure and tubular retractor assisted procedure for cervical radiculopathy: results of a randomized controlled study. J Korean Med Sci. 2009;24:649-653. Winder MJ, Thomas KC. Minimally invasive versus open approach for cervical laminoforaminotomy. Can J Neurol Sci. 2011;38:262-267. Ruetten S, Komp M, Merk H, Godolias G. A new full-endoscopic technique for cervical posterior foraminotomy in the treatment of lateral disc herniations using 6.9-mm endoscopes: prospective 2-year results of 87 patients. Minim Invasive Neurosurg. 2007;50:219-226. Ruetten S, Komp M, Merk H, Godolias G. Full-endoscopic cervical posterior foraminotomy for the operation of lateral disc herniations using 5.9-mm endoscopes: a prospective, randomized, controlled study. Spine. 2008;33:940-948. Oertel JM, Philipps M, Burkhardt BW. Endoscopic posterior cervical foraminotomy as a treatment for osseous foraminal stenosis. World Neurosurg. 2016;91:50-57. Kim CH, Shin KH, Chung CK, Park SB, Kim JH. Changes in cervical sagittal alignment after single-level posterior percutaneous endoscopic cervical diskectomy. Global Spine J. 2015;5:31-38.

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REFERENCES

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Fountas KN, Kapsalaki EZ, Nikolakakos LG, Smisson HF, Johnston KW, Grigorian AA, et al. Anterior cervical discectomy and fusion associated complications. Spine. 2007;32:2310-2317. Albert TJ, Vacarro A. Postlaminectomy kyphosis. Spine. 1998;23:2738-2745. Chiba K, Ogawa Y, Ishii K, Takaishi H, Nakamura M, Maruiwa H, et al. Long-term results of expansive open-door laminoplasty for cervical myelopathy--average 14-year follow-up study. Spine. 2006;31:2998-3005. McAnany SJ, Kim JS, Overley SC, Baird EO, Anderson PA, Qureshi SA. A meta-analysis of cervical foraminotomy: open versus minimally-invasive techniques. Spine J. 2015;15:849-856. Clark JG, Abdullah KG, Steinmetz MP, Benzel EC, Mroz TE. Minimally invasive versus open cervical foraminotomy: a systematic review. Global Spine J. 2011;1:9-14. O'Toole JE, Sheikh H, Eichholz KM, Fessler RG, Perez-Cruet MJ. Endoscopic posterior cervical foraminotomy and discectomy. Neurosurg Clin N Am. 2006;17:411-422. Kim CH, Kim KT, Chung CK, Park SB, Yang SH, Kim SM, et al. Minimally invasive cervical foraminotomy and diskectomy for laterally located soft disk herniation. Eur Spine J. 2015;24:3005-3012. Shin DA, Kim KN, Shin HC, Yoon DH. The efficacy of microendoscopic discectomy in reducing iatrogenic muscle injury. J Neurosurg Spine. 2008;8:39-43. Adamson TE. Microendoscopic posterior cervical laminoforaminotomy for unilateral radiculopathy: results of a new technique in 100 cases. J Neurosurg. 2001;95:51-57. Franzini A, Messina G, Ferroli P, Broggi G. Minimally invasive disc preserving surgery in cervical radiculopathies: the posterior microscopic and endoscopic approach. Acta Neurochir Suppl. 2011;108:197-201. Lawton CD, Smith ZA, Lam SK, Habib A, Wong RH, Fessler RG. Clinical outcomes of microendoscopic foraminotomy and decompression in the cervical spine. World Neurosurg. 2014;81:422-427. Ahn Y, Lee SH, Chung SE, Park HS, Shin SW. Percutaneous endoscopic cervical discectomy for discogenic cervical headache due to soft disc herniation. Neuroradiology. 2005;47:924-930. Yang JS, Chu L, Chen L, Chen F, Ke ZY, Deng ZL. Anterior or posterior approach of full-endoscopic cervical discectomy for cervical intervertebral disc herniation? A comparative cohort study. Spine. 2014;39:1743-1750.

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Fig. 1 Preoperative computed tomography scans (a). Magnetic resonance imaging (MRI)

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showing right-side osseous foraminal stenosis (b) and without cervical herniation of C5/6 (c).

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Fig. 2 The medial edge of the articular facet joint was confirmed by needle puncture through

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frontal X ray image (a). The lateral X ray image was used to determine and locate the posterior part

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of the facet joint (b).

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Fig. 3 The obturator was placed along the back wall of the nerve root canal and the medial

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margin of the facet joint (a). The endoscope was introduced, and the entire procedure was

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performed under direct visualization on a monitor (b).

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Fig. 4 The crosses show the nerve root of C6. The stars show the superior facet. The long arrow

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shows the inferior facet.

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Fig. 5 During the endoscopic procedure, partial facetectomy was performed using a high-speed

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grinding drill to expand the nerve root canal. The crosses show that the nerve root of C6 is

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relaxed. The stars show the thecal sac. The long arrow shows the enlargement of the posterior

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wall of the nerve root canal.

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Fig. 6 Mean values and change trend chart of VAS and NDI. ****P < 0.0001 versus pre; ####P

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< 0.0001 versus 1 month post-surgery; #P < 0.05 versus 1 month post-surgery.

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Fig. 7 The bony channel (a) and enlargement of intervertebral foramen (b) are visible on

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postoperative CT of the cervical spine.

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ACCEPTED MANUSCRIPT Table 1 Characteristics of Patients Age(y)

1 2 3 4 5 6 7 8 9

m m m m m m f f f

43 39 47 47 52 56 43 45 46

level C5/6 C5/6 C5/6 C4/5 C6/7 C5/6 C4/5 C5/6 C6/7

Operation time(m) 75 75 85 75 75 80 80 75 100

Incision length(mm) 7 7 7 7 7 7 7 7 7

Postoperative hospital stay(d) 2 2 3 3 3 3 2 3 3

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ACCEPTED MANUSCRIPT Table 2 Clinical outcomes 1month

3 months

6 months

12 months

P value

7.89±0.74 24.44±2.45

2.78±0.63 7.55±1.89

2.22±0.63 6.22±1.23

1.67±0.47 4.78±1.13

1.11±0.74 3.33±1.49

0.00 0.00

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ACCEPTED MANUSCRIPT Table 3 Modified Macnab Criteria

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Definition Complete resolution of symptoms, recovery of original work activity level and quality of life Mild symptoms, slight activity limitation that do not influence work and quality of life Symptoms relieved, activity limitations that influence work and quality of life No difference in or worsening of symptoms after versus before treatment

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Grading Excellen t Good

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ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT It is well known that radicular symptoms typically arise due to a lateral disc herniation or osteophytes in the intervertebral foramen Due to the development of minimally invasive spine surgery, MISS technology has

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become increasingly utilized by surgeons for osseous foraminal stenosis The application of posterior percutaneous full-endoscopic cervical foraminotomy (P-PECF) technique for the treatment of osseous foraminal stenosis is not

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well-reported in the literature.

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We performed the P-PECF technique in patients with only osseous foraminal stenosis

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and to report clinical and functional outcomes

ACCEPTED MANUSCRIPT Funding No funds were received in support of this work. No benefits in any form have been or will be received from a commercial party related directly or indirectly to the topic of

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this manuscript.

Disclosure of potential conflicts of interest

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Zhi-Yuan Ye, Wei-Jun Kong, Zhi-Jun Xin, Qiang Fu, Jun Ao, Guang-Ru Cao,

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Yu-Qiang Cai, and Wen-Bo Liao declare that they have no conflict of interest.

Research involving human participants and/or animals

All procedures performed in studies involving human participants were in accordance

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with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical

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standards.

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Informed consent

Informed consent was obtained from all participants included in the study.