A Randomized Trial Comparing Clinical Outcomes Between Zero-Profile and Traditional Multilevel Anterior Cervical Discectomy and Fusion Surgery for Cervical Myelopathy

Assessing Surgical Outcomes for Cage Plate System versus Stand-Alone Cage in Anterior Cervical Discectomy and Fusion: A Systematic Review and Meta-Analysis

BACKGROUND

Anterior cervical discectomy and fusion (ACDF) is a common surgical procedure for addressing cervical spine conditions. It involves the utilization of either cage plate system (CPS) or stand-alone cage (SC). The objective of our study is to compare perioperative complications, patient-reported clinical outcomes measures, and radiographic outcomes of SC versus CPS in ACDF.

METHODS

We carried out a literature search in PubMed, Embase, Cochrane library, Web of science, Medline, and Google Scholar. All studies comparing the outcomes between CPS versus SC in ACDF were included.

RESULTS

Forty-one studies, 33 observational and 8 randomized clinical trials met the inclusion criteria. We found that both devices demonstrated comparable effectiveness in monosegmental ACDF with respect to Japanese Orthopedic Association Score, Neck Disability Index score, visual analog score, and fusion rates. CPS demonstrated superior performance in maintaining disc height, cervical lordosis, and exhibited lower incidence rates of cage subsidence. SC showed significant advantages over CPS in terms of shorter surgical duration, less intraoperative bleeding, shorter duration of hospitalization, as well as lower incidence rates of early postoperative dysphagia and adjacent segment disease.

CONCLUSIONS

Most of the included studies had monosegmented fusion, and there wasn't enough data to set recommendations for the multisegmented fusions. Larger studies with longer follow-up are necessary to draw more definitive conclusions to provide evidence for clinicians to make clinical decisions.

Current advancements in therapeutic approaches in orthopedic surgery: a review of recent trends

Recent advancements in orthopedic surgery have greatly improved the management of musculoskeletal disorders and injuries. This review discusses the latest therapeutic approaches that have emerged in orthopedics. We examine the use of regenerative medicine, including stem cell therapy and platelet-rich plasma (PRP) injections, to accelerate healing and promote tissue regeneration. Additionally, we explore the application of robotic-assisted surgery, which provides greater precision and accuracy during surgical procedures. We also delve into the emergence of personalized medicine, which tailors treatments to individual patients based on their unique genetic and environmental factors. Furthermore, we discuss telemedicine and remote patient monitoring as methods for improving patient outcomes and reducing healthcare costs. Finally, we examine the growing interest in using artificial intelligence and machine learning in orthopedics, particularly in diagnosis and treatment planning. Overall, these advancements in therapeutic approaches have significantly improved patient outcomes, reduced recovery times, and enhanced the overall quality of care in orthopedic surgery.

The Role of Osteobiologics in Augmenting Spine Fusion in Unplated Anterior Cervical Discectomy and Fusion Compared to Plated Constructs: A Systematic Review and Meta-analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVE

To compare clinical and radiographic outcomes as well as complications of unplated vs plated anterior cervical discectomy and fusion (ACDF) surgery considering the role of osteobiologics in single- and multi-level procedures.

METHODS

A systematic search of PubMed/MEDLINE, Scopus, CINAHL, EMBASE, CENTRAL, Cochrane and ClinicalTrials.gov databases was performed. Briefly, we sought to identify studies comparing unplated vs. plated ACDF for cervical degenerative disc disease reporting the use of osteobiologics in terms of clinical outcomes, radiographic fusion, and complications. Data on study population, follow-up time, type of cage and plate used, type of osteobiologic employed, number of levels treated, patient-reported outcomes (PROs), radiographic outcomes and complications were collected and compared. Relevant information was pooled for meta-analyses.

RESULTS

Thirty-eight studies met the inclusion criteria. No significant difference was found in terms of clinical outcomes between groups. Unplated ACDF was characterized by reduced blood loss, operation time and length of hospital stay. Fusion was achieved by the majority of patients in both groups, with no evidence of any specific contribution depending on the osteobiologics used. Dysphagia was more commonly associated with anterior plating, while cage subsidence prevailed in the unplated group.

CONCLUSION

Unplated and plated ACDF seem to provide similar outcomes irrespective of the osteobiologic used, with minor differences with doubtful clinical significance. However, the heterogeneity and high risk of bias affecting included studies markedly prevent significant conclusions.

The efficacy of anchored stand-alone spacers in comparison to conventional cage and plate in anterior cervical discectomy and fusion surgery: A meta-analysis of randomised controlled trials for clinical and radiological outcomes

Introduction

Anterior cervical discectomy and fusion (ACDF) is commonly performed with cage and plate constructs to stabilise diseased or injured cervical segments. Despite it being a commonly performed procedure, there are notable rates of associated morbidity reported in the literature. Stand-alone spacers represent a novel form of instrumentation to conventional cage and plate constructs.

Research question

Do stand-alone spacers have improved operative characteristics and postoperative outcomes in ACDF cohorts when compared to cage and plate constructs?

Methods

A systematic review and meta-analysis was conducted of PubMed/Medline, Embase and Google Scholar databases per the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes guidelines. Studies of interest included cage and plate instrumentation versus anchored stand-alone spacers for patients undergoing ACDF. Pre- and post-operative clinical and radiological outcomes were collated and compared for significance between cohorts.

Results

10 RCTs were identified and included with 779 patients total. Mean age of the entire cohort was 50.1 years. 62% (483/779) of the cohort were male. 384 patients underwent ACDF with stand-alone cage, while 395 had ACDF with conventional cage and plate. Stand-alone spacers significantly outperformed conventional instrumentation in terms of estimated blood loss (p < 0.01), total postoperative complications (p < 0.01), dysphagia rates (p = 0.04) and adjacent segment disease (p = 0.04). Non-inferiority was evident in both patient reported outcome measures and radiological outcomes.

Conclusion

This meta-analysis highlights the efficacy of stand-alone spacers for the management of primarily cervical spondylitic disease for both single-level and multi-level pathology, and thus presents an attractive alternative to conventional instrumentation for patients undergoing ACDF surgery.

Comparison of efficacy between endoscope-assisted anterior cervical discectomy and fusion (ACDF) and open ACDF in the treatment of single-segment cervical spondylotic myelopathy

BACKGROUND

In this study, we compared the clinical efficacy of endoscope-assisted anterior cervical discectomy and fusion (ACDF) with open ACDF in the treatment of single-segment cervical spondylotic myelopathy.

METHODS

A retrospective analysis was performed on 52 patients with single-segment cervical spondylotic myelopathy between June 2021 and February 2022, including 33 males and 19 females, with a mean age of 58.42 ± 9.26) years. Among them, 28 patients were treated with endoscope-assisted ACDF (Group A), including 2 cases of C4/5 segment, 16 cases of C5/6 segment, and 10 cases of C6/7 segment; 24 patients were treated with open ACDF (Group B), including 4 cases of C4/5 segment, 11 cases of C5/6 segment, and 9 cases of C6/7 segment. The operation time, intraoperative blood loss, hospital stay, and complications were recorded and compared between the two groups. The Visual Analogue Scale (VAS) and the Japanese Orthopaedic Association (JOA) score were used for clinical evaluation during the follow-up in the 1st month and 3rd month after surgery, and at the final follow-up.

RESULTS

The 52 patients were followed up on average for 13.04 months (12-17 months). The operation time in Group A and Group B was (105.18 + 8.66) minutes and (81.88 + 6.05) minutes, the intraoperative blood loss was (84.29 + 13.45) mL and (112.92 + 17.81) mL, and the hospital stay was (6.75 + 1.29) days and (7.63 + 1.41) days, respectively. The difference between the two groups was statistically significant (P < 0.05). The VAS and JOA scores in the 1st month and the 3rd month after surgery and the last follow-up significantly improved in both groups compared with those before surgery (P < 0.05). The VAS and JOA scores of Group A in the 1st month, 3rd month after surgery, and the last follow-up were better than those in Group B (P < 0.05). The complication rate in Group A was 7% (2/28), which was not significantly different from the 17% (4/24) in Group B (P > 0.05).

CONCLUSION

Both endoscope-assisted ACDF and open ACDF can achieve satisfactory clinical efficacy in the treatment of single-segment cervical spondylotic myelopathy. Although the operation time of endoscope-assisted ACDF is prolonged, it has the advantages of clear vision, thorough decompression, less blood loss, and reduced risk of nerve damage, and is worthy of clinical promotion and application.

Self-locking stand-alone cage versus cage-plate fixation in monosegmental anterior cervical discectomy and fusion with a minimum 2-year follow-up: a systematic review and meta-analysis

BACKGROUND

Currently, self-locking stand-alone cages (SSC) are commonly applied in anterior cervical discectomy and fusion (ACDF), as are cage-plate constructs (CPC). However, it remains controversial concerning the long-term effectiveness of both apparatuses. Our purpose is to compare long-term effectiveness of SSC with CPC in monosegmental ACDF.

METHODS

Four electronic databases were queried to identify studies comparing SSC versus CPC in monosegmental ACDF. The meta-analysis was carried out with the use of the Stata MP 17.0 software package.

RESULTS

Ten trials with 979 patients were included. Compared to CPC, SSC significantly reduced operative time, intraoperative blood loss, duration of hospitalisation, cervical Cobb angle at final follow-up, 1-month postoperative dysphagia rate, and incidence of adjacent segment degeneration (ASD) at final follow-up. No significant difference was found regarding 1-month postoperative cervical Cobb angle, JOA scores, NDI scores, fusion rate and cage subsidence rate at final follow-up.

CONCLUSION

Both devices achieved similar long-term effectiveness in monosegmental ACDF regarding JOA scores, NDI scores, fusion rate and cage subsidence rate. SSC had significant advantages over CPC in reducing surgical duration, intraoperative bleeding, duration of hospitalisation, as well as rates of dysphagia and ASD after surgery. Therefore, SSC is a better option than CPC in monosegmental ACDF. However, SSC is inferior to CPC in maintaining cervical curvature at long-term follow-up. Whether radiological changes affect clinical symptoms needs confirmation in trials with longer follow-up.

Anterior cervical tunnectomy and fusion (ACTF): a novel technique for cervical canal decompression

OBJECTIVE

To describe a novel surgical technique note coined as anterior cervical tunnectomy and fusion (ACTF) which applying on removal of posterior vertebral bony protrusions or soft extrusions.

METHODS

Total twenty-three patients from January 2016 to January 2021 who experienced with spinal cord compression and performed by ACTF were retrospectively reviewed. Herein, relevant information including patient's gender, age, BMI, intraoperative time, intraoperative blood loss, postoperative complications and postoperative hospitalized stay were collected. Furthermore, JOA and VAS score were both collected. Moreover, imaging parameters were measured and calculated on radiographs. Correlated data were analyzed by t test. Significance was considered when P < 0.05.

RESULTS

All patients in this study were validated with favorable outcomes and none of postoperative complications. The Nurick grade of patients dramatically deceased postoperation (P < 0.001). And postoperative VAS score of patients (P < 0.001), as well as JOA score (P < 0.001), was given dramatical significance comparing to preoperation. Furthermore, occupying rate (OR) (P < 0.001) was obviously reduced while space available cord (SAC) (P < 0.001) and diameter of spinal cord (P < 0.001) was significantly increased postoperation. Meanwhile, disc height of involved segment, C2-7 SVA, and C2-C7 Cobb angle were measured on sagittal plane of lateral radiograph. Postoperative disc height of involved segment (P < 0.001) significantly elevated comparing to preoperation. However, there were no significance on C2-7 SVA (P = 0.460) and C2-C7 Cobb angle (P = 0.097).

CONCLUSIONS

The novel surgical technique coined by ACTF is a practicable approach during taking charge of bony and soft narrowing behind vertebral space.

Changes in cervical alignment of Zero-profile device versus conventional cage-plate construct after anterior cervical discectomy and fusion: a meta-analysis

BACKGROUND

Anterior cervical diskectomy and fusion (ACDF) has been widely accepted as a gold standard for patients with cervical spondylotic myelopathy (CSM). However, there was insufficient evidence to compare the changes in the cervical alignment with different fusion devices in a long follow-up period. This meta-analysis was performed to compare the radiologic outcomes and loss of correction (LOC) in cervical alignment of Zero-profile (ZP) device versus cage-plate (CP) construct for the treatment of CSM.

METHODS

Retrospective and prospective studies directly comparing the outcomes between the ZP device and CP construct in ACDF were included. Data extraction was conducted and study quality was assessed independently. A meta-analysis was carried out by using fixed effects and random effects models to calculate the odds ratio and mean difference in the ZP group and the CP group.

RESULTS

Fourteen trials with a total of 1067 participants were identified. ZP group had a lower rate of postoperative dysphagia at the 2- or 3-month and 6-month follow-up than CP group, and ZP group was associated with a decreased ASD rate at the last follow-up when compared with the CP group. The pooled data of radiologic outcomes revealed that there was no significant difference in postoperative and last follow-up IDH. However, postoperative and last follow-up cervical Cobb angle was significantly smaller in the ZP group when compared with the CP group. In subgroup analyses, when the length of the last follow-up was less than 3 years, there was no difference between two groups. However, as the last follow-up time increased, cervical Cobb angle was significantly lower in the ZP group when compared with the CP group.

CONCLUSION

Based on the results of our analysis, the application of ZP device in ACDF had a lower rate of postoperative dysphagia and ASD than CP construct. Both devices were safe in anterior cervical surgeries, and they had similar efficacy in correcting radiologic outcomes. However, as the last follow-up time increased, ZP group showed greater changes cervical alignment. In order to clarify the specific significance of LOC, additional large clinical studies with longer follow-up period are required.

Is the Zero-P Spacer Suitable for 3-Level Anterior Cervical Discectomy and Fusion Surgery in Terms of Sagittal Alignment Reconstruction: A Comparison Study with Traditional Plate and Cage System

The Zero-P spacer was primarily developed aiming to reduce the morbidity associated with the traditional anterior cervical plate. During the past decade, many authors have reported the use of Zero-P spacers for anterior cervical discectomy and fusion (ACDF) of one or two segments. Nevertheless, there is still a paucity of knowledge on the safety and feasibility of using Zero-P spacers for 3-level fixation. The objective of this study was to investigate the clinical and radiological outcomes, with a focus on the sagittal alignment reconstruction of 3-level ACDF surgery using Zero-P spacers versus those using a traditional plate and cage system. From Sep 2013 to Aug 2016, a total of 44 patients who received 3-level ACDF surgery due to cervical spondylotic myelopathy were recruited. The Zero-P spacer was used in 23 patients (group ZP) and the traditional plate and cage system in 21 (group PC). Clinical outcomes were analyzed by Neck Disability Index (NDI) and Japanese Orthopedic Association (JOA) scores, and dysphagia was evaluated using the Bazaz score. Radiological outcomes, including fusion rate, adjacent segment degeneration (ASD), and especially changes in cervical sagittal alignment, were analyzed. The NDI and JOA scores did not differ significantly between the two groups postoperatively (p > 0.05); however, there was significantly less dysphagia in patients using Zero-P spacers at the 3- and 6-month follow-up (p < 0.05). At the 24-month follow-up, the fusion rate and ASD were similar between the two groups (p > 0.05). Interestingly, patients using Zero-P spacers had a significantly lower postoperative C2-7 Cobb angle and fused segment Cobb angle, compared to those using a traditional plate and cage system (p < 0.05); meanwhile, the fused segment disc wedge was also found to be significantly smaller in patients using Zero-P spacers after surgery (p < 0.05). Moreover, we further divided patients into subgroups according to their cervical lordosis. In patients with a preoperative C2-7 Cobb angle ≤ 10°, significantly less cervical and local lordosis, as well as disc wedge, were seen in group ZP after surgery (p < 0.05), while in others with a preoperative C2-7 Cobb angle > 10°, no significant difference in postoperative changes of the cervical sagittal alignment was seen between group ZP and group PC (p > 0.05). Zero-P spacers used in 3-level ACDF surgery could provide equivalent clinical outcomes and a lower rate of postoperative dysphagia, compared to the traditional plate and cage system. However, our results showed that it was inferior to the cervical plate in terms of sagittal alignment reconstruction for 3-level fixation. We recommend applying Zero-P spacers for 3-level ACDF in patients with good preoperative cervical lordosis (C2-7 Cobb angle > 10°), in order to restore and maintain physiological curvature of the cervical spine postoperatively.

Stand-alone anterior cervical decompression and fusion surgery: A cohort study evaluating a shaped cage without plates or screws

Background

The anterior approach to the cervical spine is the most commonly used surgery with effective decompression and less surgical trauma. Anterior plate construct (APC) is considered a standard technique. However, it appears to cause implant failure and postoperative dysphagia. Due to these reasons, locking stand-alone cages (LSCs) without the addition of an anterior plate have been developed and gained popularity in the past decade. In theory, an LSC could provide immediate load-bearing support to the anterior column of the cervical spine and may enhance the rate of arthrodesis. However, screw skiving and backing off are known complications of LSC. Given the characteristic shape of cervical discs, we wondered whether there may be a role for a shape-conforming cage without screws and plates to achieve desired outcomes, i.e., a true stand-alone cage (TSC). A single surgeon cohort using the cage in a heterogenic set of indications was evaluated.

Methods

A total of 45 patients with degenerative cervical conditions who underwent surgery using TSC using CoRoent Small Contoured peek cage (Nuvasive, San Diego, CA) and Orthoblend™ (Medtronics, Memphis, TN) were retrospectively reviewed. Comparisons between preoperative and postoperative Numeric Rating Scale (NRS), the modified AAOS-Modems disability outcome, Neck Disability Index (NDI) scores, and Short Form 36 were evaluated. Operative time, the occurrence rate of fusion, lordosis change of cervical spine, and occurrence rate of complications were evaluated.

Results

There were one-level (n = 15), two-level (n = 24), and three-level (n = 6) cases making a total of 81 cages implanted and studied. The mean operative time was 132.7 min. The group demonstrated significant improvements in NRS, AAOS-Modems disability outcome, and NDI scores after surgery (mean follow-up 12 months). The cervical lordosis at pre- and last follow-up period was 8.7 ± 2.2° and 8.3 ± 3.2°, respectively. The complication rate was 21.2%.

Conclusions

TSC yielded satisfactory long-term clinical and radiological outcomes; this preliminary report can form the basis of a cost–benefit analysis study either prospectively or by way of meta-modeling comparing APC, LSC to TSC.

A randomized controlled study of two different fixations in anterior cervical discectomy of multilevel cervical spondylotic myelopathy

Background: To compare the efficacy of anterior cervical discectomy and hybrid fusion (ACDHF) with short-segment plate plus self-locking, stand-alone intervertebral cages versus traditional anterior cervical discectomy and fusion (ACDF) with long-segment plate for multilevel cervical spondylotic myelopathy (MCSM). Methods: All the patients were randomly divided into two groups. 30 cases underwent ACDHF with short-segment plate and self-locking stand-alone cages (hybrid group), while the other 30 cases received ACDF with long-segment plate (control group). In patients meeting the inclusion and exclusion criteria, operation time, blood loss, postoperative drainage volume, length of stay (LOS), visual analogue scale for neck pain (VASNP) scores, Japanese Orthopaedic Association (JOA) score, and the cervical lordosis before and after the operation (5 days, 3, 6, 12 months after operation and final follow-up) were evaluated. The postoperative complications were analyzed as well. Results: All operations were performed uneventfully with followed-up. Compared with ACDF, ACDHF showed a shorter operation time, less intraoperative blood loss and postoperative drainage (p < 0.05). There were no significant difference in LOS between two groups (p ˃ 0.05). Both approaches significantly improved the JOA scores, VASNP scores and the cervical lordosis (p < 0.05). Based on Bazaz grading system, hybrid group had a lower incidence of dysphagia than control group in follow-up periods of 5 days, 3 and 6 months (p < 0.05). Conclusion: ACDF and ACDHF are both effective methods of restoring cervical lordosis following MCSM, but hybrid surgery minimizes intraoperative injury and postoperative dysphagia, making it a viable treatment option for the disorder.

Comparative analysis of the biomechanics of anterior cervical discectomy and fusion with multiple segmental plates fixation versus single multilevel plate fixation: a finite element study

BACKGROUND

This study aimed to compare the biomechanical differences between anterior cervical discectomy and fusion (ACDF) with multiple-level separate plates and conventional long plates by using finite element analysis.

METHODS

The following four finite element models were created to simulate various fixations: (1) C4-6 ACDF with multiple plates, (2) C4-6 ACDF with a single plate, (3) C3-6 ACDF with multiple plates, and (4) C3-6 ACDF with a single plate. The maximum Von-mises stress of the cage and fixation, compressive force of the adjacent intervertebral discs and range of motion (ROM) of different segments in the four models were calculated and analyzed.

RESULTS

For C4-6 ACDF, the maximum Von-mises stress of the cage and fixation was lower in the multiple plate fixation model in all motion states. Similarly, for the C3-6 ACDF models, the peak stress of the C3-4 and C5-6 cages was lower with multiple plates fixation in all motions but the stress of the C4-5 cage in the multiple plates model was slightly higher in flexion, bending and rotation. Besides, applying multiple plates in C3-6 ACDF models resulted in a decreased maximum stress of the fixation under different motions except for bending. In both the C4-6 ACDF and C3-6 ACDF models, the ROM values of the adjacent motion segments were lower in the multiple plates models in extension, bending and rotation. In the C4-6 ACDF models, the peak stress on the adjacent intervertebral discs in the multiple plates models was slightly smaller. In C3-6 ACDF models, the maximum stress on the adjacent intervertebral discs was larger in the single-plate model under flexion, bending and rotation movements.

CONCLUSION

Multiple plates fixation has a positive effect on increasing stiffness and maintaining the ROM of adjacent segments, indicating lower risk of construct failure and adjacent segment degeneration. Further studies are required to confirm its efficacy in clinical practice.

Dysphagia as a Postoperative Complication of Anterior Cervical Discectomy and Fusion

Anterior cervical discectomy and fusion (ACDF), despite its possible complications, remains the gold standard for the surgical treatment of patients with radiculopathy and/or myelopathy caused by cervical intervertebral disc herniation or spondylosis. Despite its high rate of incidence, postoperative dysphagia following ACDF is still poorly understood; its pathogenesis remains relatively unknown, and its risk factors are still a subject of debate.

The aim of this study is to review the incidence, pathogenesis, diagnosis, and methods of prevention of dysphagia in ACDF patients. To this end, a literature review was conducted based on the PubMed internet database. Article titles were searched by using the following keywords: “dysphagia” and “anterior cervical discectomy and fusion” or “ACDF”. The search was limited to prospective clinical studies evaluating dysphagia after ACDF surgery. Studies published in non-English languages, retrospective studies, cadaveric studies, reviews, case reports, study protocols, and commentary studies were excluded.

Initially, 335 studies were identified after a primary search. After the application of the exclusion criteria, 73 studies remained for the final analysis. This literature review focused on identifying the rate of dysphagia and the various risk factors leading to this complication by comparing and evaluating the current literature with a wide spectrum of heterogeneity concerning patients, surgeons, and surgical techniques. A mean dysphagia rate of 19.4% (95% CI: 9.6%-29.1%) based on the findings of the included studies correlating dysphagia directly with ACDF procedures was calculated. Various established risk factors leading to dysphagia include the female sex, smoking, the surgical approach, rhBMP-2 use, and multilevel surgery, while zero-profile devices seem to reduce dysphagia risk. The diagnosis is based on clinical and radiological findings, especially prevertebral soft-tissue swelling. However, videofluoroscopic and endoscopic studies have been recently used for the evaluation of dysphagia. The role of local administration of steroids in the prevention of dysphagia has not yet been clarified. This review underscores the prevailing rudimentary understanding of the problem of dysphagia after ACDF procedures and highlights the need for more sensitive, factor-specific studies for understanding the impact of various risk factors on the incidence rate of dysphagia.

Outcomes of cervical degenerative disc disease treated by anterior cervical discectomy and fusion with self-locking fusion cage

BACKGROUND

Cervical degenerative disc (CDD) disease is a common type of spondylosis. Although anterior cervical discectomy and fusion (ACDF) is the preferred treatment for CDD disease, internal fixation with a titanium plate may cause various complications. The invention of the ACDF with a self-locking fusion cage (ROI-C) has effectively decreased the incidence of postoperative complications.

AIM

To observe the outcomes of CDD disease treated by ACDF with a ROI-C.

METHODS

Ninety patients with CDD disease treated at our hospital from March 2019 to March 2021 were included. They were divided into two groups (control group and observation group, n = 45 in each) using a random number table. Patients in the control group received ACDF plus internal fixation with a titanium plate. Those in the observation group received ACDF + ROI-C placement. The two groups of patients were compared in terms of surgical parameters, pain, cervical spine function, range of motion, and complications.

RESULTS

The two groups of patients showed no significant differences in surgical time, blood loss, drainage volume, and length of hospital stay (P > 0.05). No significant differences in the visual analogue scale (VAS), Japanese Orthopedic Association (JOA), and neck disability index (NDI) scores were observed between the two groups before surgery (P > 0.05). The VAS and NDI scores in the observation group were considerably lower than those in the control group after surgery; however, the JOA scores in the observation group were significantly higher than those in the control group (P < 0.05). No significant differences were observed in cervical disc height and the range of motion of the superior or inferior adjacent vertebrae between the two groups before surgery (P > 0.05). The disc height in the observation group was larger than that in the control group after surgery. The range of motion of both the superior and inferior adjacent vertebrae was significantly smaller in the observation group than in the control group (P < 0.05). The incidence of complications was only 2.22% in the observation group compared to 15.56% in the control group, and the difference was statistically significant (P < 0.05).

CONCLUSION

Cervical spine function restoration was better with ROI-C with internal fixation in ACDF than with conventional titanium plates in ACDF for CDD disease.

Intervertebral-spreader-assisted anterior cervical discectomy and fusion prevents postoperative axial pain by alleviating facet joint pressure

Objective

To evaluate the relationship of postoperative cervical axial pain with different vertebral distraction methods used during ACDF procedures in cervical spondylosis patients.

Methods

Ninety-four single-level cervical spondylotic myelopathy patients with significantly loss of intervertebral disc height who underwent ACDF surgery in our institute between January 2018 and January 2020 were enrolled. Cervical spine lateral radiographs were taken preoperatively, 3 days, 1-month, 2-month and 6-month after the surgery. The intervertebral disc height (IDH), interfacet distance (IFD), JOA (Japanese Orthopaedic Association) score, NDI (Neck Disability Index) score, nVAS (Neck Visual Analogue Scale) score and aVAS (Arm Visual Analogue Scale) score were measured. The correlation of clinical parameters and intervertebral disc height was evaluated. Then the correlation of clinical outcomes and different distraction method was evaluated. The patients were randomly divided into two groups, one uses Casper pin distractor system alone for distraction (Caspar alone group) and the other uses spreader assisted distraction method (Casper + spreader group). In biomechanical study, four cervical spine cadavers were selected for facet pressure measurements under different vertebral distraction methods, and the facet joint pressure was measured using force sensors.

Results

Satisfactory cervical fusion and neurological recovery were achieved in all patients. No significant correlation of IDH, IFD, JOA, NDI or aVAS with nVAS score was found. No significant difference between the change in disc height and clinical outcomes was found. However, by comparing the clinical parameters of patients in different vertebral distraction groups, we found significant changes in the early nVAS and NDI scores (P = 0.11, P = 0.48) of the Casper + spreader group (3 days postoperation), and was associated with a better nVAS score at 2 months postoperation (P < 0.05). The biomechanical study in cervical cadavers also showed significantly and continuously decreased facet joint pressure in the spreader assisted vertebral distraction group (P < 0.01).

Conclusions

Spreader-assisted vertebral distraction method effectively alleviates postoperative neck pain in degenerative cervical spondylosis patients treated with ACDF. The mechanism may be related to the transient relief of facet joint pressure during the vertebral distraction procedure in ACDF.

Comparison of outcomes between Zero-p implant and anterior cervical plate interbody fusion systems for anterior cervical decompression and fusion: a systematic review and meta-analysis of randomized controlled trials

Purpose

The clinical outcomes of using a zero-profile for anterior cervical decompression and fusion were evaluated by comparison with anterior cervical plates.

Methods

All of the comparative studies published in the PubMed, Cochrane Library, Medline, Web of Science, EBSOChost, and EMBASE databases as of 1 October 2021 were included. All outcomes were analysed using Review Manager 5.4.

Results

Seven randomized controlled studies were included with a total of 528 patients, and all studies were randomized controlled studies. The meta-analysis outcomes indicated that the use of zero-profile fixation for anterior cervical decompression and fusion was better than anterior cervical plate fixation regarding the incidence of postoperative dysphagia (P < 0.05), adjacent-level ossification (P < 0.05), and operational time (P < 0.05). However, there were no statistically significant differences in intraoperative blood loss, Visual Analogue Scale, Neck Disability Index, or Japanese Orthopaedic Association scale (all P > 0.05) between the zero-profile and anterior cervical plate groups.

Conclusions

The systematic review and meta-analysis indicated that zero-profile and anterior cervical plates could result in good postoperative outcomes in anterior cervical decompression and fusion. No significant differences were found in intraoperative blood loss, Visual Analogue Scale, Neck Disability Index, or Japanese Orthopaedic Association scale. However, the zero-profile is superior to the anterior cervical plate in the following measures: incidence of postoperative dysphagia, adjacent-level ossification, and operational time.

PROSPERO registration CRD42021278214.

Application of a new integrated low-profile anterior plate and cage system in single-level cervical spondylosis: a preliminary retrospective study

Background

Although ACDF has been widely used in treating cervical spondylosis and related diseases, the complications along with this anterior surgical technique have hindered its application and affected the postoperative outcome of the patients. Here, we investigated the clinical and radiological outcomes of a new integrated low-profile anterior plate and cage system for anterior cervical discectomy and fusion (ACDF) in treating cervical spondylosis.

Methods

A total of 96 cervical spondylosis patients who underwent single-level ACDF between 2018 to 2020 in our institute were enrolled. There were 28 patients using the new implants and 68 patients using the zero-profile (Zero-P) implants. The Japanese Orthopedic Association (JOA) score and the visual analog scale (VAS) were used to evaluate the clinical outcomes. The cervical and segmental Cobb angle and range of motion (ROM) were used to assessed the radiological outcomes. Incidence of complications were also recorded. All data were recorded at pre-operation, 6-month and 12-month post-operation.

Results

All patients were followed-up for at least 1-year, the mean follow-up time was over one year. The fusion rate was similar in the two groups. There was no significant difference in the postoperative JOA score recovery rate, postoperative VAS score of neck and arm pain, postoperative ROM, and incidence of complications between two groups (P > 0.05). However, postoperative cervical and segmental Cobb angle were better maintained in the new low-profile implant group compared to Zero-P group.

Conclusions

The clinical outcomes of the new low-profile implant were satisfactory and comparable to that of zero-profile system. It may have advantages in improving and maintaining the cervical lordosis, and can be an alternative device for single-level cervical spondylosis treated with ACDF.

Anterior Cervical Discectomy and Fusion Using Zero-P System for Treatment of Cervical Spondylosis: A Meta-Analysis

Objective

The current study aimed to explore the efficacy of Zero profile intervertebral fusion system (Zero-P) and traditional anterior plate cage system (PC) in the treatment of cervical spondylotic myelopathy (CSM). Further, the present study evaluated effects of the treatments on medical security, height of intervertebral disc, adjacent-level ossification development (ALOD), and adjacent segmentation disease (ASD) through a systematic retrospective analysis.

Methods

Studies on Zero-P system and traditional anterior plate cage system for ACDF in the treatment of CSM were searched in PubMed, Web of Science, Ovid, Embase, and Cochrane Library databases. Two independent researchers screened articles, extracted data, and evaluated the quality of the articles based on the inclusion and exclusion criteria of the current study. RevMan5.3 software was used for meta-analysis following the guidelines of Cochrane collaboration network. Cervical curvature, interbody fusion rate, preoperative and postoperative disc height index (DHI), fusion cage sinking rate, postoperative dysphagia, ASD, ALOD, and loosening of screw were compared between the two groups.

Results

A total of 17 literatures were included in the present study, including 6 randomized controlled trials and 11 observational studies. The studies comprised a total of 1204 patients with CSM, including 605 patients in the Zero-P system group (Zero-P group) and 599 patients in the traditional animal plate cage group (PC group). Results of this meta-analysis showed that postoperative dysphagia [OR = 0.40, CI (0.28, 95% 0.58), P < 0.00001], ALOD [OR = 0.09, CI (0.02, 95% 0.39), P = 0.001], ASD [OR = 0.42, CI (0.20, 95% 0.86), P = 0.02], and screw loosening [OR = 0.20, CI (0.08, 95% 0.52), P = 0.0009] of the Zero-P group were significantly lower compared with the PC group. On the other hand, preoperative cervical curvature [WMD = −0.23, CI (−1.38, 95% 0.92), P = 0.69], postoperative cervical curvature [WMD = −0.38, CI (−1.77, 95% 1.01), P = 0.59], cage sinking rate [OR = 1.41, CI [0.52, 95% 3.82], P = 0.50], intervertebral fusion rate [OR = 0.76, CI (0.27, 95% 2.48), P = 0.38], preoperative DHI [WMD = −0.04, CI (−0.14, 95% 0.22), P = 0.65], and postoperative DHI [WMD = 0.06, CI (−0.22, 95% 0.34), P = 0.675] were not significantly different between the two groups.

Conclusion

It was evident that the Zero-P system used in ACDF is superior compared with the traditional anterior plate cage system in postoperative dysphagia, avoiding ALOD, ASD, and screw loosening.

Is there a difference in the outcomes of anterior cervical discectomy and fusion among female patients with different menopausal statuses?

BACKGROUND

The surgical outcomes of anterior cervical discectomy and fusion (ACDF) in female patients according to menopausal status remain unclear. The objective of this study was to investigate the differences in these outcomes among female patients with different menopausal statuses.

METHODS

Ninety-one patients undergoing single-level or consecutive two-level ACDF with a minimum 12-month postoperative follow-up were included in this study. There were 38 patients in the premenopausal group, 28 patients in the early postmenopausal group, and 25 patients in the late postmenopausal group. The clinical outcomes were evaluated by means of the neck disability index (NDI) scores, Japanese Orthopedic Association (JOA) scores, and visual analog scale (VAS) scores. Radiological parameters included cervical lordosis (CL), the functional spinal unit (FSU) angle, range of motion (ROM) of the total cervical spine, ROM of the FSU, anterior and posterior FSU height, implant subsidence, adjacent segment degeneration (ASD), and Hounsfield unit (HU) values.

RESULTS

All groups showed significant improvements in their JOA, VAS, and NDI scores (P < 0.05). The differences in preoperative and final follow-up CL, ROM of C2-7, FSU angle, and ROM of FSU were not statistically significant among the three groups (P > 0.05). The anterior FSU height loss rate showed a significant difference (P = 0.043), while there was no difference in the posterior FSU height loss rate (P = 0.072). The fusion rates in the early and late postmenopausal groups were consistently lower than those in the premenopausal group during the follow-up period. All patients had satisfactory outcomes at the final follow-up.

CONCLUSION

There were no significant differences in clinical or other related outcomes of single-level or consecutive two-level ACDF in the long term among female patients with different menopausal statuses. However, the early bony fusion rates and anterior FSU height loss rates were poorer in late postmenopausal patients than in premenopausal or early postmenopausal patients. Hence, importance should be attached to the protection of late postmenopausal patients in the early postoperative period to guarantee solid bony fusion.

Improved Dysphagia Outcomes in Anchored Spacers Versus Plate-Screw Systems in Anterior Cervical Discectomy and Fusion: A Systematic Review

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVE

To perform a systematic review of clinical outcomes between stand-alone anchored spacers and traditional cages with plate fixation for dysphagia and pseudoarthrosis using data from clinical trials.

METHODS

Our search protocol was added to PROSPERO register and systematic review using PRISMA method was performed. Then, we systematically searched for studies addressing stand-alone anchored spacers in patients who underwent ACDF. Mean Neck Disability Index (NDI), dysphagia incidence % (Dinc%), and Swallowing-Quality of Life (SQOL) scores during preoperative, immediate postoperative and last follow-up visits were extracted. Chi-square and analysis of variance (ANOVA) tests were used for statistical comparisons (P ≤ .05).

RESULTS

The initial search generated 506 articles in CENTRAL and 40 articles in MEDLINE. Finally, 14 articles were included. Total number of patients was 1173 (583 anchored stand-alone and 590 plate). Dinc% scores were statistically significantly lower in the stand-alone anchored spacer compared to the plate-screw construct (P ≤ .05). ANOVA showed no statistically significant difference in the comparisons of SQOL. On the other hand, NDI scores were statistically significantly lower in baseline of stand-alone anchored spacer and the plate-screw construct compared with both immediate postoperative and last follow-up visits (P ≤ .05).

CONCLUSIONS

Our study results revealed that the stand-alone anchored spacers were associated with less dysphagia in the immediate and last follow-up.

Is Cervical Disc Replacement Valuable in 3-Level Hybrid Surgery Compared with 3-Level Anterior Cervical Discectomy and Fusion?

BACKGROUND

Cervical degenerative disc disease is common in clinical practice. Surgery is among the most effective treatments for patients with cervical radiculopathy, myelopathy, or stenosis. Which treatment is the best option for multilevel cervical degenerative disc disease is controversial. Hybrid surgery, combined cervical disc replacement and anterior cervical discectomy and fusion, may be an alternative treatment for multilevel cervical degenerative disc disease.

METHODS

Sixty-four patients with 3-level hybrid surgery and 37 patients with 3-level anterior cervical discectomy and fusion were reviewed retrospectively. Clinical outcomes were based on visual analog scale, Neck Disability Index, 36-Item Short Form Survey, and Japanese Orthopaedic Association scores and Japanese Orthopaedic Association recovery rate. Radiologic assessments included range of motion (ROM) of C2-C7 and adjacent level and cervical lordosis of C2-C7. Perioperative parameters, fusion condition, and complications were assessed.

RESULTS

There were no statistical differences observed between the 2 groups for Japanese Orthopaedic Association, Neck Disability Index, or visual analog scale scores. The hybrid surgery group had better physical and mental 36-Item Short Form Survey scores than the fusion group at 1-year follow-up (physical component summary: 49.34 vs. 46.70, P = 0.012; mental component summary: 45.67 vs. 43.95, P = 0.004). ROM of C2-C7 and adjacent levels was less compromised in the hybrid group compared with baseline (64.60% vs. 51.34%, P < 0.001). Cervical lordosis was decreased with time in both groups but was acceptable at final follow-up, and both groups showed solid fusion.

CONCLUSIONS

Normal ROM and solid fusion were achieved at both arthroplasty and arthrodesis levels. ROM of replacement levels in different locations of the 3-level construct was acceptable.

Locking stand-alone cage versus anterior plate construct in anterior cervical discectomy and fusion: a systematic review and meta-analysis based on randomized controlled trials

PURPOSE

To evaluate the efficacy of locking stand-alone cage (LSC) compared with anterior plate construct (APC) in anterior cervical discectomy and fusion (ACDF).

METHODS

A comprehensive literature search was carried out in PubMed, Embase, Web of Science, and Cochrane Library to screen randomized controlled trials (RCTs) that directly compared LSC with APC in ACDF. The Cochrane Collaboration's tool was used for assessment of study quality. Data were analyzed with the Review Manager 5.3 software.

RESULTS

A total of seven RCTs were included. The results revealed no significant differences between LSC and APC in ACDF regarding the fusion rate, Japanese Orthopaedic Association score, visual analogue scale score, neck disability index score, hospital stay, subsidence rate, cervical lordosis, segmental Cobb angle, and disc height. However, LSC was associated with a significantly shorter operation time, less blood loss, lower overall incidence of dysphagia, and lower adjacent-level ossification (ALO) rate compared with APC.

CONCLUSION

In summary, LSC is not only a safe and effective device for ACDF but also has the advantages of significantly reduced operation time, blood loss, overall incidence of dysphagia, and ALO rate over APC. Therefore, LSC is a better alternative than APC for the patients undergoing ACDF procedures.

A comparison study between hybrid surgery and anterior cervical discectomy and fusion for the treatment of multilevel cervical spondylosis

AIMS

Whether to perform hybrid surgery (HS) in contrast to anterior cervical discectomy and fusion (ACDF) when treating patients with multilevel cervical disc degeneration remains a controversial subject. To resolve this we have undertaken a meta-analysis comparing the outcomes from HS with ACDF in this condition.

METHODS

Seven databases were searched for studies of HS and ACDF from inception of the study to 1 September 2019. Both random-effects and fixed-effects models were used to evaluate the overall effect of the C2-C7 range of motion (ROM), ROM of superior/inferior adjacent levels, adjacent segment degeneration (ASD), heterotopic ossification (HO), complications, neck disability index (NDI) score, visual analogue scale (VAS) score, Japanese Orthopaedic Association (JOA) score, Odom's criteria, blood loss, and operating and hospitalization time. To obtain more credible results contour-enhanced funnel plots, Egger's and Begg's tests, meta-regression, and sensitivity analyses were performed.

RESULTS

In total, 17 studies involving 861 patients were included in the analysis. HS was found to be superior to ACDF in maintaining C2-C7 ROM and ROM of superior/inferior adjacent levels, but HS did not reduce the incidence of associated level ASD. Also, HS did not cause a higher rate of HO than ACDF. The frequency of complications was similar between the two techniques. HS failed to achieve more favourable outcomes than ACDF using the NDI, VAS, JOA, and Odom's scores. HS did not show any more advantages in operating or hospitalization time but did show reduction in blood loss.

CONCLUSION

Although HS maintained cervical kinetics, it failed to reduce the incidence of ASD. This finding differs from previous reports. Moreover, patients did not show more benefits from HS with respect to symptom improvement, prevention of complications, and clinical outcomes. Cite this article: Bone Joint J 2020;102-B(8):981-996.

Two-level ACDF with a zero-profile stand-alone spacer compared to conventional plating: a prospective randomized single-center study

PURPOSE

Stand-alone zero-profile devices have already proven safety, and a reduced dysphagia rate was assumed. So far, no level-one evidence is available to prove the proposed advantages of zero-profile implants in multilevel procedures. The aim of this RCT was to compare the clinical and radiological outcome of a zero-profile spacer versus cage + plate in two-level ACDF.

METHODS

Consecutive patients with contiguous two-level cDD were randomly assigned either to the interventional group (zero-profile device) or to the control group (cage + plate). Primary endpoint of the study was the prevalence of dysphagia at 24 months. Disability, progress of adjacent segment degeneration, fusion status and loss of correction were analyzed as secondary outcome measure. Primary outcome parameter was statistically analyzed by Chi-square test.

RESULTS

Forty-one patients met inclusion criteria and were randomly assigned to the interventional and the control group. Dysphagia was frequent in either group at 3 months FU favoring interventional group (p = 0.078). At final FU, less patients of the interventional group complained about dysphagia, but the difference was not significant. No relevant differences at final FU were recorded for NPDI, loss of correction and adjacent-level degeneration. Fusion rate was slightly lower in the interventional group.

DISCUSSION

Two-level ACDF either by a stand-alone zero-profile spacer or cage + plate is safe. Using a zero-profile cage dysphagia was infrequent at 24 months, but the value did not reach statistical significance in comparison with the cage + plate. Hence, this randomized trial was not able to prove the proposed clinical superiority for dysphagia rates for zero-profile anchored spacer in two-level cDD.

The Utility of Cervical Spine Bracing As a Postoperative Adjunct to Multilevel Anterior Cervical Spine Surgery

Background

Use of cervical bracing/collar subsequent to anterior cervical spine discectomy and fusion (ACDF) is variable. Outcomes data regarding bracing after ACDF are limited. Here, we study the impact of bracing on short-term outcomes related to safety, quality of care, and direct costs in multilevel ACDF.

Methods

Retrospective cohort analyses of all consecutive patients undergoing multilevel ACDF with or without bracing from 2013 to 2017 was undertaken (n = 616). Patient demographics and comorbidities were analyzed. Tests of independence and logistic regressions were used to assess differences in length of stay (LOS), discharge disposition (home, assisted rehabilitation facility [ARF], or skilled nursing facility [SNF]), quality-adjusted life year (QALY), direct cost, readmission within 30 days, and emergency room (ER) visits within 30 days.

Results

Amongst the study population, 553 were braced and 63 were not braced. There was no difference in comorbidities (P > .05) such as obesity, smoking, chronic obstructive pulmonary disease, hypertension, coronary artery disease, congestive heart failure, and problem list number. A significant difference in American Society of Anesthesiologists (ASA) score was found, with more ASA 2 patients in the braced cohort and more ASA 3 patients in the unbraced cohort (P = .007). LOS was extended for the unbraced group (median 156.9 ± 211.4 versus 86.67 ± 130.6 h, P = .003), and ER visits within 30 days were 0.21 times less likely in the braced group (P = .006). There was no difference in readmission (P = .181), QALY gain (P = .968), and direct costs (P = .689).

Conclusion

Bracing following multilevel cervical fixation does not alter short-term postoperative course or reduce the risk for early adverse outcomes in a significant manner.

Application of Zero-profile Spacer in the Treatment of Three-level Cervical Spondylotic Myelopathy: 5-year Follow-up Results

STUDY DESIGN

A retrospective study.

OBJECTIVE

To assess the long-term results of zero-profile spacer for 3-level anterior cervical discectomy and fusion (ACDF).

SUMMARY OF BACKGROUND DATA

Although widely used, there are still controversies about the long-term results of zero-profile spacer, especially in multilevel cases.

METHODS

Cases received 3-level ACDF for cervical spondylotic myelopathy (CSM) using either zero-profile spacer (n = 27) (ZP Group), or plate and cages (n = 34) (PC Group), and with 5-year follow-up were reviewed. Neurological function and life quality were assessed by modified Japanese Orthopaedic Association (mJOA) score, Neck Disability Index (NDI), and Short-Form 36 (SF-36) score. Disc height, cervical lordosis, fusion rate, and surgical complications were observed.

RESULTS

Neurological recovery and life quality improvement were similar in both groups. Disc height and cervical lordosis (C2-7 Cobb angle) were well restored after operations, but lost in both groups during follow-up. Loss of correction (LOC) in disc height was larger in ZP Group (11.38% vs 5.71%, P < 0.05) at 5-year follow-up. LOC of cervical lordosis in ZP group constantly grew from 11.28% to 48.13% during 5-year follow-up, significantly higher than that in the PC group (from 7.43% to 14.01%) (P < 0.05). The rate of postoperative dysphagia was no statistical difference between the two groups, and symptoms were all disappeared within 1 year. There were 10 levels of adjacent segment degeneration (1 in ZP Group, and 10 in PC Group, P = 0.02). Cage subsidence (11 of 81 levels, 13.58%) and screw migration (2 of 81 levels, 2.47%) were only observed in the ZP Group. The migrated screws in one case were surgically removed. Fusion was achieved in all cases.

CONCLUSIONS

In long-term follow-up of 3-level ACDF for CSM, zero-profile spacer has the similar clinical results, but loss of correction of disc height and cervical alignment were significantly higher, compared with anterior plate and cages.

LEVEL OF EVIDENCE

3.

Incidence of Subsidence of Seven Intervertebral Devices in Anterior Cervical Discectomy and Fusion: A Network Meta-Analysis

BACKGROUND

Subsidence is an incapacitating complication in anterior cervical discectomy and fusion (ACDF). However, the debate over which of the intervertebral devices is associated with lower incidence of subsidence remains to be settled.

METHODS

Seven dominant techniques comprising cage with plate (CP), iliac bone graft with plate (IP), Zero-profile cage with screws (Zero-P), ROI-C cages with clips (ROI-C), polyether ether ketone cage alone (PCA), iliac crest autogenous graft (ICAG), and titanium cage alone (TCA) were examined. The incidences of subsidence in the different groups were calculated and compared.

RESULTS

A total of 30 studies with 2264 patients were identified. Overall, the CP group presented the lowest incidence of subsidence, and its incidence was significantly lower than that in the Zero-P group, the PCA group, the ICAG group, and the TCA group (P < 0.05). The incidence of subsidence in the IP group was significantly lower than that in the PCA group, the ICAG group, and the TCA group (P < 0.05). In single-level ACDF, the CP group presented the lowest incidence of subsidence, and its incidence was significantly lower than that in the PCA group and the TCA group (P < 0.05). No difference was found between single-level and multilevel ACDF and the incidence of subsidence was higher in those undergoing single-level ACDF.

CONCLUSIONS

CP and IP resulted in a lower rate of subsidence than cage alone or ICAG. Zero-P and ROI-C cages led to similar subsidence rates with plate. All types of intervertebral device can be applied to both single-level and multilevel ACDF with comparable subsidence rate.

Complications of anterior cervical spine surgery: a systematic review of the literature

The anterior approach to the cervical spine is commonly utilized for a variety of degenerative, traumatic, neoplastic, and infectious indications. While many potential complications overlap with those of the posterior approach, the distinct anatomy of the anterior neck also presents a unique set of hazards. We performed a systematic review of the literature to assess the etiology, presentation, natural history, and management of these complications. Following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), a PubMed search was conducted to evaluate clinical studies and case reports of patients who suffered a complication of anterior cervical spine surgery. The search specifically included articles concerning adult human subjects, written in the English language, and published from 1989 to 2019. The PubMed search yielded 240 articles meeting our criteria. The overall rates of complications were as follows: dysphagia 5.3%, esophageal perforation 0.2%, recurrent laryngeal nerve palsy 1.3%, infection 1.2%, adjacent segment disease 8.1%, pseudarthrosis 2.0%, graft or hardware failure 2.1%, cerebrospinal fluid leak 0.5%, hematoma 1.0%, Horner syndrome 0.4%, C5 palsy 3.0%, vertebral artery injury 0.4%, and new or worsening neurological deficit 0.5%. Morbidity rates in anterior cervical spine surgery are low. Nevertheless, the unique anatomy of the anterior neck presents a wide variety of potential complications involving vascular, aerodigestive, neural, and osseous structures.

Association between sagittal balance and adjacent segment degeneration in anterior cervical surgery: a systematic review and meta-analysis

Background

ASD is a relatively common degenerative alteration after cervical surgery which occurs above or below the fused segment. In addition, some patients may need reoperation to treat severe ASD after the primary surgery. It was considered that sagittal balance is correlated with postoperative clinical outcomes; however, few studies have reported the influence of sagittal balance on ASD. The present study is designed to investigate whether sagittal balance impacts the pathology of adjacent segment disease (ASD) in patients who undergo anterior cervical surgery for degenerative cervical disease.

Methods

Databases including Pubmed, Embase, Cochrane library, and Web of Science were used to search for literature published before June 2018. Review Manager 5.3 was used to perform the statistical analysis. Sagittal balance parameters before and after surgery were compared between patients with and without ASD. Weighted mean difference (WMD) was summarized for continuous data and P < 0.05 was set for the level of significance.

Results

A total of 221 patients with ASD and 680 patients without ASD from seven articles were studied in this meta-analysis. There were no significant differences in most sagittal balance parameters between the two groups, except for postoperative cervical lordosis (CL) (WMD -3.30, CI -5.91, − 0.69, P = 0.01).

Conclusions

Some sagittal balance parameters may be associated with the development of ASD after anterior cervical surgery. Sufficient restoration of CL may decrease the incidence of ASD. The results in present study needed to be expanded carefully and further high-quality studies are warranted to investigate the impact of sagittal balance on ASD.

Electronic supplementary material

The online version of this article (10.1186/s12891-019-2800-0) contains supplementary material, which is available to authorized users.

Outcome Evaluation of Zero-Profile Device Used for Single-Level Anterior Cervical Discectomy and Fusion with Osteoporosis Compared without Osteoporosis: A Minimum Three-Year Follow-Up Study

OBJECTIVE

We compared the mid-term efficacy and safety of anterior cervical discectomy and fusion (ACDF) using a Zero-Profile device for cervical degenerative disc disease (CDDD) with and without osteoporosis.

METHODS

We performed a retrospective study of elderly patients with CDDD treated by single-level ACDF with a Zero-Profile device. The patients were divided into group A (osteoporosis) and group B (no osteoporosis) according to the bone mineral density. The clinical outcomes (Japanese Orthopaedic Association, neck disability index, visual analog scale, and short-form 36 scores), radiological outcomes (cervical lordosis and fusion rate), and complications were reviewed at each follow-up examination.

RESULTS

All procedures were successfully performed in all patients. The Japanese Orthopaedic Association, neck disability index, visual analog scale, and short-form 36 scores and cervical lordosis were significantly improved postoperatively in both groups (P < 0.05). However, no significant difference was found between the 2 groups at each follow-up point (P > 0.05). No significant difference was found in the fusion rate at 3 months postoperatively (group A, 88.9%; group B, 90.0%), dysphagia rate at 1 month postoperatively (group A, 11.1%; group B, 15.0%), or cage subsidence rate at the final follow-up visit (group A, 11.1%; group B, 10.0%; P > 0.05). All patients achieved solid fusion, and no patient had dysphagia at the final follow-up examination.

CONCLUSIONS

ACDF with the Zero-Profile device can be used as an effective and reliable treatment for single-level CDDD with osteoporosis.