Posterior percutaneous endoscopic cervical discectomy through lamina-hole approach for cervical intervertebral disc herniation

Posterior Lateral Endoscopic Cervical Discectomy Through a Lateral Mass Approach in the Treatment of Cervical Spondylotic Radiculopathy

OBJECTIVE

The present study outlines the feasibility, safety, and short-term clinical outcomes of posterior lateral endoscopic cervical discectomy (PLECD) through a lateral mass approach for treating cervical spondylotic radiculopathy (CSR).

METHODS

This single-center retrospective observational study involved 30 patients with single-level CSR who had failed conservative treatment and presented with clinical symptoms consistent with imaging findings undergoing PLECD via a lateral mass approach. Primary outcomes included the visual analog scale (VAS) for neck and arm pain, the Japanese Orthopedic Association (JOA) score, and the modified MacNab criteria. Radiographic follow-up consisted of static and dynamic cervical radiographs and computed tomographic scans.

RESULTS

Thirty patients (13 men and 17 women; mean age 48.8 ± 11.9 years) underwent this procedure, and the mean operative time was 74.90 ± 13.52 minutes. Mean follow-up was 7.37 ± 2.17 months. The VAS scores for the neck and arm decreased significantly at the last follow-up (neck, 26.80 ± 4.75 to 9.87 ± 1.78; arm, 71.30 ± 8.48 to 14.73 ± 4.00) (P < 0.05). The JOA score also decreased from 13.47 ± 1.36 to 15.90 ± 0.92 at the last follow-up (P < 0.05). Twenty-nine patients demonstrated satisfactory outcomes based on the modified MacNab criteria at the last follow-up. All patients exhibited a positive clinical response, experiencing relief from symptoms. Postoperative computed tomography (CT) scans confirmed the complete removal of lesions.

CONCLUSIONS

PLECD through a lateral mass approach, as an alternative to conventional "keyhole" approaches, proves to be a novel and viable therapeutic option for CSR, demonstrating both high efficacy and safety.

Evolution of Cervical Endoscopic Spine Surgery: Current Progress and Future Directions-A Narrative Review

Cervical endoscopic spine surgery is rapidly evolving and gaining popularity for the treatment of cervical radiculopathy and myelopathy. This approach significantly reduces muscular damage and blood loss by minimizing soft tissue stripping, leading to less postoperative pain and a faster postoperative recovery. As scientific evidence accumulates, the efficacy and safety of cervical endoscopic spine surgery are continually affirmed. Both anterior and posterior endoscopic approaches have surfaced as viable alternative treatments for various cervical spine pathologies. Newer techniques, such as endoscopic-assisted fusion, the anterior transcorporeal approach, and unilateral laminotomy for bilateral decompression, have been developed to enhance clinical outcomes and broaden surgical indications. Despite its advantages, this approach faces challenges, including a steep learning curve, increased radiation exposure for both surgeons and patients, and a relative limitation in addressing multi-level pathologies. However, the future of cervical endoscopic spine surgery is promising, with potential enhancements in clinical outcomes and safety on the horizon. This progress is fueled by integrating advanced imaging and navigation technologies, applying regional anesthesia for improved and facilitated postoperative recovery, and incorporating cutting-edge technologies, such as augmented reality. With these advancements, cervical endoscopic spine surgery is poised to broaden its scope in treating cervical spine pathologies while maintaining the benefits of minimized tissue damage and rapid recovery.

Outcomes and Complications Associated With the Learning Curve for Endoscopic Cervical Foraminotomy: A Systematic Review and Meta-Analysis

STUDY DESIGN

A systematic review and meta-analysis.

OBJECTIVE

The objective of this study is to examine the impact of the learning curve for endoscopic cervical foraminotomy for clinical outcomes and patient safety.

SUMMARY OF BACKGROUND DATA

Endoscopic cervical foraminotomy is a minimally invasive surgical technique emerging in the literature for surgical management of cervical radiculopathy without the use of open incision. The adoption of endoscopic cervical foraminotomy may be hindered by the learning curve, although no review and meta-analysis exists to date on the topic.

MATERIALS AND METHODS

A systematic review and meta-analysis was performed using PubMed, CINAHL, and MEDLINE from database inception until July 11, 2023. Inclusion criteria were articles that examined endoscopic cervical foraminotomy, reported outcomes, and/or complications for endoscopic cervical spine surgery relevant to the learning curve and had full-text. A random effects meta-analysis was performed for outcomes and complications.

RESULTS

A total of three articles (n=203 patients) were included from 792 articles initially retrieved. The learning curves from four surgeons were examined with a FWM 21 procedures until the competency phase. There was no significant difference in the postoperative hospitalization length ( P =0.669), postoperative recovery room time ( P =0.415), intraoperative blood loss ( P =0.064), and total complication rates (10.9% vs . 1.2%, P =0.139) between endoscopic cervical foraminotomy procedures performed in the learning phase as compared with the competency phase of the learning curve. There was a significant decrease in operative time from the learning phase to the competency phase ( P =0.005).

CONCLUSION

Competency was achieved on the learning curve for endoscopic cervical foraminotomy after about 21 procedures. There is no significant difference in postoperative hospitalization time, postoperative recovery room time, intraoperative blood loss, and complication rates between the learning phase and the competency phase of the learning curve for endoscopic cervical foraminotomy, noting the relatively small sample size of this study that may underpower this finding.

Biomechanical analysis of the door-shaped titanium plate in single-level anterior cervical discectomy and fusion

BACKGROUND

Analyse and discuss the immediate stability of the cervical spine after anterior cervical discectomy and fusion using a door-shaped titanium plate and compare it with the traditional titanium plate, to provide biomechanical evidence for the rationality and effectiveness of the door-shaped titanium plate in clinical applications.

METHODS

Ten adult goat C4/5 vertebral bodies were obtained, and models were prepared using denture base resin. Biomechanical experiments were performed on the specimens before internal fixation. MTS was used to conduct non-destructive biomechanical loading tests in six directions, including flexion, extension, left-right bending, and left-right torsion, recording the range of motion (ROM) and neutral zone (NZ) of each specimen. The specimens were then randomly divided into two groups: the study group was fixed with a door-shaped titanium plate, and the control group was fixed with a traditional titanium plate. ROM and NZ in each direction were measured again. After measurements, both groups were subjected to 0.5 Hz torsion loading with a torque of 2 N m for a total of 3000 cycles, followed by measuring ROM and NZ in six directions once more.

RESULTS

Compared to before fixation, ROM and NZ in both groups significantly decreased in all six directions after fixation, with statistical significance (P < 0.05); after fixation, the study group showed slightly lower values for various mechanical reference parameters compared to the control group, with no statistical significance (P > 0.05); after 3000 torsional loads, both internal fixation groups showed increased ROM and NZ compared to after fixation but to a lower extent, and no screw or titanium plate loosening was observed. Compared to before fixation, the differences were still statistically significant (P < 0.05), with the study group having slightly lower ROM and NZ values in all directions compared to the control group, with no statistical significance (P > 0.05).

CONCLUSION

The door-shaped titanium plate exhibits mechanical properties similar to the traditional titanium plate in all directions, and its smaller size and simpler surgical operation can be used for anterior cervical endoscopic surgery, reducing surgical trauma. It is clinically feasible and deserves further research and promotion.

Surgical Technique of Central and Over-the-Top Full-Endoscopic Decompression of the Cervical Spine: A Technical Note

Endoscopic surgery of the cervical spine is constantly evolving and the spectrum of its indications has expanded in recent decades. Full-endoscopic techniques have standardized the procedures for posterior and anterior access. The full-endoscopic approach was developed to treat degenerative diseases with the least possible invasion and without causing instability of the cervical spine. The posterior full-endoscopic approach is indicated for the treatment of diseases of the lateral part of the vertebral segment, such as herniations and stenoses of the lateral recess and vertebral foramen. There has been little discussion of this approach to the treatment of central stenosis of the cervical spine. This technical note describes a step-by-step surgical technique for central and over-the-top full-endoscopic decompression in the cervical spine, using a 3.7 mm working channel endoscope. This technique has already been shown to be effective in a recent case series with a 4.7 mm working channel endoscope, and may represent a new treatment option for central or bilateral lateral recess stenosis. There is also the possibility of a bilateral full-endoscopic approach, but this may be associated with greater muscle damage and a longer operative time. Case series and comparative studies should be encouraged to confirm the safety and utility of this technique.

Posterior endoscopic decompression combined with anterior cervical discectomy and fusion versus posterior laminectomy and fusion for multilevel cervical spondylotic myelopathy: a retrospective case-control study

OBJECTIVE

To compare the clinical efficacy of surgical treatment for multilevel cervical spondylotic myelopathy (MCSM) between the hybrid procedure, posterior endoscopic decompression (PED) combined with anterior cervical discectomy fusion (ACDF), and posterior cervical laminectomy and fusion (PCLF).

METHODS

A retrospective analysis was performed on 38 patients who received surgical treatment for MCSM from January 2018 to December 2021, including 19 cases in hybrid procedure group (13 males and 6 females), followed up for 10 to 22 (12.8 ± 10.3) months, and 19 cases in PCLF group (15 males and 4 females), followed up for 10 to 21 (11.7 ± 8.9) months. Perioperative information, including operation time, intraoperative blood loss, length of hospitalization, and complications, were compared between two groups. Visual analogue scale (VAS) of pain, neck disability index (NDI) and Japanese Orthopaedic Association (JOA) score were recorded to evaluate clinical efficacy. Cervical lordosis was calculated by radiographic examination.

RESULTS

Intraoperative blood loss, length of hospital stay were less in hybrid group than PCLF group, while operation time is longer in hybrid group, with a statistically significant difference (p < 0.05). Increased lordosis was better in hybrid group. There was no significant difference in preoperative VAS, JOA and NDI at pre-operation and final follow-up between two groups. But at post-operation and final follow-up, VAS was less in hybrid group than PCLF group (p < 0.05). There were 2 cases of neurostimulation symptoms in hybrid group, 2 cases of C5 nerve root palsy, 2 cases of subcutaneous fat necrosis and 1 case of dural tear in PCLF group, and all patients relieved with symptomatic treatment.

CONCLUSION

The hybrid procedure of PED combined with ACDF showed satisfied clinical outcome, with less intraoperative blood loss, shorter length of hospitalization and lower post-operative neck pain than PCLF. It is an effective surgical treatment for MCSM.

Full Endoscopic Spine Surgery for Cervical Spondylotic Myelopathy: A Systematic Review

BACKGROUND

Cervical spondylotic myelopathy (CSM) may seriously affect quality of life. In the literature, there is scarce evidence of the pros and cons of full endoscopic spine surgery in the treatment of CSM. The main purpose of this study was to conduct a systematic review to elucidate the efficacy of full endoscopic spine surgery in the management of patients with CSM.

METHODS

This systematic review was conducted in accordance with the PRISMA guidelines. A systematic search of Web of Science, PubMed MEDLINE, Embase, and Cochrane Library was conducted from the database inception to February 1, 2023.

RESULTS

The study included 183 patients and their age was 56.78 ± 7.87 years. The average surgical time calculated was 96.34 ± 33.58 minutes. Intraoperative blood loss ranged from a minimal amount to 51 mL. The average duration of hospital stay was 3.56 ± 1.6 days. The average span for follow-up was on an interval of 18.7 ± 6.76 months. Significant improvements were noted in all aspects of functional outcomes and image results after full endoscopic cervical spine surgery, with no major complications.

CONCLUSIONS

The current study found that both anterior transcorporeal and posterior surgical approaches could be used for the treatment of CSM with a full endoscopic technique. Indications of full endoscopic cervical spine surgery for CSM included cervical disc herniation, central canal stenosis, calcified ligamentum flavum, and ossification of the posterior longitudinal ligament. Improved postoperative outcomes with acceptable surgical complications were noted in this systematic review.

Full Endoscopy Combined with Allogeneic Bone Grafting for Benign Spinal Lesions: Technical Notes and Preliminary Clinical Results

Benign lesions of the spine include benign tumors and tumor-like lesions of the spine, which usually occur in the thoracic and lumbar vertebrae. The incidence rate is low, accounting for about 1% of primary bone tumors. Few cases of endoscopic treatment of benign spinal lesions have been reported in the literature. Here, we introduce a new surgical technique using full endoscopy and allogeneic bone grafting to treat benign spinal lesions. All patients in this study successfully underwent the operation, and their pain was significantly relieved postoperatively. The patient VAS scores decreased from 3.07 ± 0.70 preoperatively to 0.33 ± 0.49 at the last follow-up visit (p < 0.05). The mean total blood loss (including drainage blood) was 16.67 ± 6.98 mL. The mean operative time was 63.33 ± 7.23 min. No patients developed numbness in the corresponding segmental distribution after surgery, none of the patients had serious postoperative complications, and none had focal recurrence during follow-up requiring reoperation. Patients reported symptom relief throughout the whole follow-up period. We believe that endoscopic surgery preserves the ligaments and soft tissues around the vertebral body, and that this technique is feasible with minimal trauma, rapid recovery, and good outcomes at short-term follow-up. This minimally invasive treatment modality offers a new option for the treatment of patients with benign spinal lesions.

Global Trends and Hotspots in Endoscopic Discectomy: A Study Based on Bibliometric Analysis

OBJECTIVE

With the advancement of minimally invasive spine surgery, endoscopic discectomy (ED) has become a common technique for degenerative disease of the spine. The present study aimed to explore the knowledge structure, emerging trends, and future research hotspots in this field.

METHODS

All relevant publications on ED from 2002 to 2021 were extracted from the Web of Science databases. Key bibliometric indicators, including countries/regions, institutions, authors, journals, references, and keywords were calculated and evaluated using VOSviewer and CiteSpace software.

RESULTS

A total of 1,196 articles and reviews were included for analysis. The number of publications regarding ED increased yearly. From the quality and quantity viewpoint, China, South Korea, and the United States were the major contributors in this field. The most influential institution in the field of ED was Wooridul Spine Hospital. We identified 3,488 authors, among which Lee SH had the most significant number of papers, and Ruetten S was cocited most often. <World Neurosurgery was the journal with the most papers, and Spine was the most commonly cocited journal. Keywords were stratified into 4 clusters by VOSviewer software: cluster 1 (clinical outcomes of ED in the treatment of lumbar disc herniation); cluster 2 (surgical technique of percutaneous endoscopic lumbar discectomy); cluster 3 (clinical outcomes of ED in the treatment of lumbar spinal stenosis); and cluster 4 (clinical outcomes of percutaneous endoscopic cervical discectomy). Several topics including lateral recess stenosis, spinal stenosis, and reoperation were considered as the next hotspot in ED research.

CONCLUSION

ED research has gained considerable attention over the last 2 decades. Our bibliometric findings illuminate the publication trends and research hotspots of the ED field, which may provide useful references for scholars and decision-makers interested in this field.

Outcome of Anterior and Posterior Endoscopic Procedures for Cervical Radiculopathy Due to Degenerative Disk Disease: A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVES

Cervical spine endoscopic discectomy and decompression have gained popularity in the last decade. This review aimed to shed light on the current outcomes of cervical spine endoscopic procedures for degenerative disc disease (DDD) and to calculate a pooled estimate of various outcome measures.

METHODS

We retrieved articles published in English related to endoscopic cervical spine procedures from 3 central databases from inception until September 2020. A subgroup analysis based on the anterior versus the posterior approach was performed.

RESULTS

Thirty-one articles fulfilled the eligibility criteria and included 1,410 patients. A successful outcome was observed in 91.3% (88.6-93.4%, P = 0.000). This percentage was lower for the anterior approach (89.6% [85.8-92.5%], P = 0.000) than for the posterior approach (94.2% [90.4-96.5%], P = 0.000). A higher percentage of poor outcomes was reported for the anterior approach (5.7% [3.2-10.1%], P = 0.000 vs. 2.3% [1-5.5%], P = 0.000 for the posterior approach). The overall complication rate was 7.2% (5.2-9.8%, P = 0.000). There was a slightly higher complication rate for the anterior approach (7.9% [4.5-13.3%], P = 0.000) than for the posterior approach (6.7% [4.4-10%], P = 0.000). The revision rate was 4.2% (2.6-6.8%, P = 0.000); and 4.2% (1.8-9.7%, P = 0.000) for the anterior approach and 4.00% (2.2-7.4%, P = 0.000) for the posterior approach.

CONCLUSIONS

There is a higher success rate and lower complication rate with the posterior approach than with the anterior approach. However, high-quality randomized controlled trials are vital to evaluate the efficacy of these procedures.

Clinical efficacy and safety of posterior minimally invasive surgery in cervical spondylosis: a systematic review

Background

Posterior minimally invasive surgery has been increasingly used in in recent years for the clinical treatment of cervical spondylosis. However, this treatment remains challenging and has not been comprehensively reported. The aim of this study was to provide a systematic review of posterior minimally invasive treatment for cervical spondylosis to demonstrate the clinical efficacy and safety of this procedure.

Method

We collected information from patients with myelopathy or radiculopathy cervical spondylosis who underwent posterior minimally invasive surgery and verified the clinical efficacy and safety of these surgeries with different measurement indicators from five electronic databases: the Nurick, visual analog scale score, Japanese Orthopaedic Association (JOA) score, Neck Disability Index (NDI), EuroQol Five Dimensions Questionnaire (EQ-5D) score, Short-Form Health Survey Physical Component Summary (SF12-PCS) questionnaire score, Short-Form Health Survey Mental Component Summary (SF12-MCS) questionnaire score, and the MOS item short form health survey (HF-36) score. The decompression effect, cervical spine stability, average surgery time, surgical blood loss volume, length of hospital stay, and related complications were included in the descriptive analysis. Reporting of this protocol followed the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines checklist.

Results

We identified 14 observational studies of cervical spondylosis with 479 patients, mainly including 197 cases of myelopathy and 207 cases of radiculopathy. Channel and endoscopic techniques were used. This study was certified by PROSPERO: CRD42021290074. Significant improvements in the quantitative indicators (Neck-VAS in 9 studies, JOA in 7 studies, NDIs in 5 studies, Nurick, ARM-VAS, and EQ-5D in 2 studies each, and the SF12-PCS, SF12-MCS, and HF-36 in 1 study each) were observed between pre- and postoperation (P < 0.05), and satisfactory clinical significance was acquired in the descriptive indicators [average surgery time (94.56 ± 37.26 min), blood loss volume (68.78 ± 103.31 ml), average length of stay (2.39 ± 1.20 d), and cervical spine stability after surgery]. Additionally, we showed that there was a 4.9% postoperative complication rate and the types of complications that may occur.

Conclusion

Posterior minimally invasive surgery is an effective and safe method for the treatment of cervical spondylosis and is a recommended optional surgical procedure for single-segment myelopathy and radiculopathy.

[Posterior percutaneous endoscopy via vertical anchor technique combined with trench technique for single-segmental central cervical disc herniation]

Objective

To investigate the clinical feasibility, safety, and effectiveness of posterior percutaneous endoscopy via vertical anchor technique combined with trench technique for single-segmental central cervical disc herniation.

Methods

Between July 2017 and August 2019, 13 patients with the single-segmental central cervical disc herniation suffering from various neurologic deficits were treated with posterior percutaneous endoscopy via vertical anchor technique combined with trench technique. There were 6 males and 7 females with an average age of 50.5 years (range, 43-64 years). Disease duration ranged from 3 to 17 months (mean, 9.2 months). The clinical symptoms of 5 cases were mainly neck pain, radiculopathy, and numbness in upper limbs, and the visual analogue scale (VAS) score was 6.60±0.55. The clinical symptoms of 8 cases were myelopathy including upper extremities numbness, weakness, and trouble walking, and the modified Japanese Orthopedic Association (mJOA) score was 12.75±0.71. The surgery-related complications, operation time, and intraoperative blood loss were recorded, and the results of clinical symptoms were measured by VAS scores and mJOA scores.

Results

All procedures were completed successfully, no severe complications such as dural tears or cerebrospinal fluid leakage occurred. The operation time ranged from 83 to 164 minutes (mean, 101.2 minutes). The intraoperative blood loss was 25-50 mL (mean, 33.1 mL). After operation, 12 of 13 cases were followed up 10-24 months (mean, 17.6 months). The VAS scores of patients with preoperative pain symptoms were 2.40±0.55 on the first day after operation and 1.80±0.45 at last follow-up, which were significantly lower than those before operation ( P<0.05). The mJOA scores of patients with the symptoms of spinal cord injury were 12.63±0.52 on the first day after operation and 14.29±0.95 at last follow-up, and the score at last follow-up was significantly higher than that before operation ( P<0.05). Acute extremities weakness occurred for the postoperative hematoma formation in 1 case (disc herniation at C _{4, 5}) presented with myelopathy preoperatively, and muscle strength was recovered after the clearance of hematoma and spinal cord decompression under percutaneous endoscopy.

Conclusion

Posterior percutaneous endoscopy via vertical anchor technique and trench technique for single-segmental central cervical disc herniation was clinical feasible, safe, and effective, and could be an alternative approach to the treatment of central cervical disc herniation.

Comparative evaluation of posterior percutaneous endoscopy cervical discectomy using a 3.7 mm endoscope and a 6.9 mm endoscope for cervical disc herniation: a retrospective comparative cohort study

Background

Posterior percutaneous endoscopy cervical discectomy (p-PECD) is an effective strategy for the treatment of cervical diseases, with a working cannula ranging from 3.7 mm to 6.9 mm in diameter. However, to date, no studies have been performed to compare the clinical outcomes of the use of endoscopes with different diameters in cervical disc herniation (CDH) patients. The purpose of this study was to compare the clinical outcomes of patients with unilateral CDH treated with p-PECD using a 3.7 mm endoscope and a 6.9 mm endoscope.

Methods

From January 2016 to June 2018, a total of 28 consecutive patients with single-level CDH who received p-PECD using either the 3.7 mm or the 6.9 mm endoscope were enrolled. The clinical results, including the surgical duration, hospitalization, visual analog scale (VAS) score and modified MacNab criteria, were evaluated. Cervical fluoroscopy, CT, and MRI were also performed during follow-up.

Results

Tthere was a significant difference in regard to the average identification time of the “V” point (18.608 ± 3.7607 min vs. 11.256 ± 2.7161 min, p < 0.001) and the mean removal time of the overlying tissue (16.650 ± 4.1730 min vs. 12.712 ± 3.3079 min, p < 0.05) for the use of the 3.7 mm endoscope and the 6.9 mm endoscope, respectively. The postoperative VAS and MacNab scores of the two endoscopes were significantly improved compared with those the preoperative scores (p < 0.05).

Conclusion

The application of both the 3.7 mm endoscope and 6.9 mm endoscope represent an effective method for the treatment of CDH in selected patients, and no significant difference can be observed in the clinical outcomes of the endoscopes. The 6.9 mm endoscope shows superiority to the 3.7 mm endoscope in terms of the efficiency of “V” point identification, the removal of overlying soft tissue and the prevention of spinal cord injury. However, the 6.9 mm endoscope may be inferior to the 3.7 mm endoscope in regards to anterior foraminal decompression due to its large diameter; this result needs to be further evaluated with the support of a large number of randomized controlled trials.

Posterior Endoscopic Cervical Decompression: Review and Technical Note

Endoscopic spine surgery for the treatment of degenerative spinal diseases from lumbar to cervical spine has accelerated over the past 2 decades. Posterior endoscopic cervical discectomy (PECD) has been described as a safe, effective, and minimally invasive procedure for cervical radiculopathy or even part of the myelopathy. This procedure also has been validated with comparable outcomes to open and microscopic surgery. Radiculopathy due to foraminal disc herniation or foraminal stenosis should be the optimum indications of this procedure. Intraoperative 3-dimensional navigation can help surgeons to get quick and great quality guidance for endoscopic surgeons. In this review, we will focus on the technical details and evidence-based results of PECD which is a promising procedure for cervical radiculopathy with the advantages of a minimally invasive method.

Structure Design and Optimization of the C5-C6 Cervical Intervertebral Fusion Cage Using the Anterior Cervical Plate and Cage Fixation System

Background

The fifth and sixth cervical vertebra (C5–C6) is the most easily injured segment encountered in clinical practice. The anterior cervical plate and cage (ACPC) fixation system is always used to reconstruct the intervertebral height and maintain the segmental stability. The postoperative effect, such as subsidence, neck pain, and non-fusion, is greatly affected by the cervical cage structure design. This study determined reasonable structure size parameters that present optimized biomechanical properties related to the postoperative subsidence often accompanied with ACPC.

Material/Methods

Twenty bionic cages with different structural sizes (distance between the center of the cage and groove, groove depth, and groove width) were designed and analyzed based on the regression optimization design and analysis method combined with FE analysis. Because a previous study showed that greater stresses on the endplate are associated with higher risk of subsidence, the optimization object was selected as the stresses on endplate to lower it.

Results

The postoperative stresses on the endplate of all cages with bionic structure design were proved to be lower than with the original one. The optimal structure size was the distance between the center of the cage and groove=0 mm, groove depth=3 mm, and groove width=4 mm. Regression analysis found the cage with optimized bionic structural parameters resulted in a 22.58% reduction of endplate stress response compared with the original one.

Conclusions

The bionic cage with optimized structural sizes can reduce the subsidence risk, suggesting that the optimization method has great potential applications in the biomechanical engineering field.

Trans-interlamina percutaneous endoscopic cervical discectomy for symptomatic cervical spondylotic radiculopathy using the new Delta system

To describe the rationale and surgical technique and compare the clinical effect of posterior percutaneous endoscopic cervical discectomy (PPECD) using the Delta system versus that of conventional PPECD (key-hole) surgery for the treatment of symptomatic cervical spondylotic radiculopathy (CSR). A retrospective analysis was performed on 106 single-segment CSR patients between February 2016 and February 2017, 50 of whom underwent conventional PPECD (key-hole), and 56 underwent PPECD using the Delta system. The operative time, intraoperative blood loss, intraoperative complications and postoperative hospital stay were recorded, and the clinical effect was evaluated by the indicators of the Neck Disability Index (NDI), arm-visual analog scale (arm-VAS), neck-VAS, EQ-5D and MacNab classification at the last follow-up. All patients underwent the operation successfully, and 106 patients were followed up. The operative time of the Delta group was 60.47 ± 0.71 min, while the operative time of the key-hole group was 75.46 ± 0.41 min. The difference between the two groups was statistically significant (P < 0.05). However, there was no significant difference between the two groups in terms of blood loss and hospital stay (P > 0.05). The VAS, NDI and EQ-5D scores of the neck and upper limbs in the two groups were significantly better than those before surgery at 1 week after surgery and at the last follow-up (P < 0.05). However, there was no significant difference between the two groups at the last follow-up (P > 0.05). At the last follow-up, there was no significant difference between the two surgical methods when evaluated using the modified MacNab criteria. The imaging results showed that the herniated disc was removed completely and the nerve root was decompressed. The complication rate in the Delta group (3/56, 5.35%) was significantly lower than that in the conventional key-hole group (5/50, 10.0%). PPECD using the Delta system for CSR may be a feasible and promising alternative surgical plan. Compared with the traditional key-hole method, this surgical system can not only provide the surgeon with a larger surgical field of vision but also reduces the operation time and complication rates.

Full endoscopic unilateral laminotomy for bilateral decompression of the cervical spine: surgical technique and early experience

Background

Full-endoscopic decompression surgery has been shown to be safe and efficacious in the lumbar spine, while its role remains to be determined in the cervical spine. We describe the utility of cervical endoscopic unilateral laminotomy for bilateral decompression (CE-ULBD) in a series of elderly patients with severe central stenosis, significant medical comorbidity, and existing cervical deformity.

Methods

A prospectively collected spine surgery registry at the University of Washington was retrospectively queried for patients with cervical spondylotic myelopathy receiving CE-ULBD. Demographic data, operative details, imaging, and patient reported outcomes, including visual analogue scale (VAS) for neck and upper extremity pain, Nurick grade, and the modified Japanese Orthopedic Association (mJOA) score, were reviewed. Description of the surgical technique is provided. Descriptive statistics were calculated.

Results

From 2014 through 2018, 10 patients with an average age of 70.2±5.0 years underwent CE-ULBD for symptomatic upper cervical stenosis due to ligamentum flavum buckling. Half of these patients had one stenotic segment, the other half had two stenotic segments. The most commonly affected segment was C3/4 (5/10 patients). Average length of surgery was 128±18.4 minutes. Average length of stay was 1.2±0.2 days. Average clinical follow-up time was 22.0±4.7 months; clinical outcomes at most recent follow-up were improved via both the Nurick grade (1.2±0.4, P<0.01) and modified Japanese Orthopedic Association (14.6±1.0, P<0.001) compared with pre-operative values. One patient experienced a transient loss of motor evoked potentials intraoperatively, but there were no cases of permanent neurological deficit.

Conclusions

Severe central cervical stenosis is a safe and viable target for full-endoscopic decompression via an interlaminar approach.

Cervicothoracic junction disc herniation: Our experience, technical remarks, and outcome

Background:

C7-D1 disc herniation is rare in comparison with other cervical levels. The incidence rates are between 3.5% and 8%. The cervicothoracic junction disc herniation can be operated posteriorly or anteriorly. The anterior approach can be challenging because of the difficulty of access resulted from the manubrium. In this article, we present our experience about cervicothoracic junction disc herniation (C7-T1) surgery.

Materials and Methods:

Between January 2008 and December 2017, 21 patients have been operated for solitary C7-T1 disc herniation. We operated 12 male patients and 9 female patients. Eight patients have been operated by the anterior approach, and 13 patients underwent surgery by the posterior approach. The mean symptoms duration was 11.4 months.

Results:

All patients had C8 cervicobrachial neuralgia. Other clinical presentations were numbness, tingling sensation, and weakness. All patients improved after surgery. We had no significant complication.

Conclusion:

We did not find a great difference between the clinical features of cervicothoracic herniated disc and other cervical levels. The anterior approach seems more difficult to carry out in particularly in large patients with the short neck. The posterior approach can be used for all types of patients except in the case of medial disc herniation.

Clinical application of large channel endoscopic decompression in posterior cervical spine disorders

Background

We investigated the clinical value of posterior percutaneous endoscopic decompression (PED) for single-segment cervical spondylotic myelopathy (CSM) and cervical spondylotic radiculopathy (CSR). Methods: Clinical data from February 2016 to March 2018 were collected for 32 patients with single-segment CSM or CSR who underwent posterior cervical percutaneous large channel endoscopic decompression and completed a regular follow-up exam at 12 months after surgery. Patient data included: age (range 30–81 years and mean of 49.5 years) and surgical information (operation time, bleeding volume, hospital stay, complications, etc.). The Japan Orthopedic Association (JOA) score and pain visual analog scale (VAS) were used to evaluate the surgical outcome for each patient. Cervical spine radiographs were used to evaluate cervical curvature (Cervical spondylotic angle (CSA), C2–7 Cobb angle) and CT and MRI were used to assess the extent of laminectomy and nerve root decompression. The JOA score, VAS score, cervical curvature were analyzed statistically, and the clinical outcome was evaluated using modified Macnab criteria at the last patient follow-up exam.

Results

The JOA and VAS scores were compared before and after surgery (1 day Pre-op; 3 days, 3 months and 12 months Post-op). The differences were statistically significant (P < 0.05). There were significant differences in cervical curvature (C2–7 Cobb angle) between the time points (1 day Pre-op; 3 days, 3 months and 12 months Post-op), but the differences were no statistically significant in CSA angle (P < 0.05) The operation time range was 45–110 min (mean 68.6 ± 23.8 min); the intraoperative blood loss range was 20–85 ml (mean28 ± 14.8 ml), and the hospital stay was 3–8 days (mean4.5 days). At the last follow-up, the clinical efficacy was evaluated using modified Macnab criteria. The results were excellent in 18 cases, good in 11 cases, and fair in 3 cases. The combined excellent and good rate was 93.75%. Postoperative CT and MRI showed that the compression of the spinal cord or nerve roots was completely relieved.

Conclusion

Endoscopic decompression of posterior cervical vertebral disorders is a safe, effective, and minimally invasive surgical procedure with rapid recovery times. This procedure warrants additional research and clinical application.

Biomechanical Comparison of Optimal Shapes for the Cervical Intervertebral Fusion Cage for C5-C6 Cervical Fusion Using the Anterior Cervical Plate and Cage (ACPC) Fixation System: A Finite Element Analysis

BACKGROUND The fifth and sixth cervical vertebrae (C5-C6) represent the high-risk segment requiring surgical correction in cervical spondylosis. Anterior cervical discectomy and fusion (ACDF) of C5-C6 includes an intervertebral fusion cage to maintain foraminal height and is combined with anterior plate fixation. The shape of the intervertebral cage can affect the postoperative outcome, including the rates of fusion, subsidence, and neck pain. This study aimed to use finite element (FE) parametric analysis to compare biomechanical properties of changes in intervertebral cage shape for C5-C6 cervical fusion using the anterior cervical plate and cage (ACPC) fixation system. MATERIAL AND METHODS Five shapes were designed for cervical intervertebral cages, square, oval, kidney-shaped, clover-shaped, and 12-leaf-shaped. The performance was evaluated following implantation into the validated normal C5-C6 FE model using simulation with five physiological conditions. The indicators included the maximum von Mises stress of the endplates, the fusion cages, and the cervical vertebrae. The postoperative subsidence-resistance properties were determined, including the interior stress responses of the intervertebral cages and the surrounding tissues. The fusion-promoting properties were evaluated by the interior stress responses of the bone grafts. RESULTS The optimal shape of the cervical intervertebral cage was the 12-leaf-shape for postoperative subsidence resistance. The kidney shape for the cervical intervertebral cage was optimal for postoperative fusion. CONCLUSIONS FE analysis identified the optimal cervical intervertebral cage design for ACPC fixation of C5-C6. This method may be useful for future developments in the design of spinal implants.