Implant complications, fusion, loss of lordosis, and outcome after anterior cervical plating with dynamic or rigid plates: two-year results of a multi-centric, randomized, controlled study

Anterior cervical controllable Antedisplacement and Fusion (ACAF) versus Anterior Cervical Corpectomy and Fusion (ACCF) for ossification of the cervical posterior longitudinal ligament (OPLL) in Chinese population: a systematic review and meta-analysis

This study aimed to systematically review and compare the efficacy and safety of anterior cervical controllable antedisplacement and fusion (ACAF) versus anterior cervical corpectomy and fusion (ACCF) in treating ossification of the cervical posterior longitudinal ligament (OPLL), focusing on surgery-related indicators and postoperative outcomes. This review was conducted and reported in accordance with the Cochrane Handbook for Systematic Reviews of Interventions guidelines and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting standards. The methodological quality of this systematic review was assessed using the Assessing the Methodological Quality of Systematic Reviews (AMSTAR) checklist. A detailed search strategy was implemented to retrieve literature from electronic databases, including PubMed, EMBASE, and the Cochrane Library, followed by quality assessment and data extraction for eligible studies. A total of 5 studies involving 366 participants were included. ACAF was associated with significantly fewer complications (OR = 0.25, 95% CI [0.12, 0.51], p = 0.000), including a lower incidence of cerebrospinal fluid (CSF) leakage (OR = 0.20, 95% CI [0.08, 0.52], p = 0.000). ACAF also showed better outcomes in postoperative neck disability index (NDI) scores (SMD = -0.48, 95% CI [-0.81, -0.15], p = 0.020), C2-C7 angle (SMD = 1.29, 95% CI [0.56, 2.03], p = 0.000), spinal canal area (SCA) (SMD = 0.93, 95% CI [0.56, 1.29], p = 0.000), and diameter of the spinal cord (DSC) (SMD = 0.38, 95% CI [0.11, 0.66], p = 0.010). Additionally, ACAF improved The Japanese Orthopedic Association (JOA) scores (SMD = 0.29, 95% CI [0.01, 0.57], p = 0.040) but required longer operation time (SMD = 1.08, 95% CI [0.01, 2.15], p = 0.049). No significant differences were found in blood loss (SMD = 0.23, 95% CI [-0.34, 0.79], p = 0.431), hospital stay (SMD = 0.65, 95% CI [-1.46, 2.76], p = 0.547), and improvement rate (IR) (SMD = 0.38, 95% CI [-0.10, 0.86], p = 0.118). The current meta-analysis indicated that ACAF surgery can effectively reduce the incidence of complications, significantly increase the spinal canal area and improve the spatial conditions of the spinal cord compared to those associated with ACCF surgery. This is more advantageous for the postoperative neurological recovery of patients. Nonetheless, it is crucial to approach these findings with a degree of caution.

The Fragility Index: Understanding Its Application in Clinical Research

With the vast increase in spinal surgery research and accessibility, critical evaluation of studies is paramount. Historically, P values and confidence intervals have been the gold standard, but more recently, the inclusion of the Fragility Index has brought a more holistic approach. The Fragility Index aims to communicate the robustness of a trial and how tenuous statistical significance may be. It can be used in conjunction with more traditional methods for evaluating research.

Anterior Cervical Discectomy and Fusion with Zero-Profile Anchored Spacer Versus Plate and Cage for 3-Level Contiguous Cervical Degenerative Disease: A Systematic Review and Meta-Analysis

OBJECTIVE

To compare the safety, clinical outcomes, and radiological results of anterior cervical discectomy and fusion (ACDF) with zero-profile anchored spacer (ZPAS) versus plate and cage (PC) for 3-level contiguous cervical degenerative disease.

METHODS

The study was registered at PROSPERO (CRD42024512706). The Web of Science core collection, PubMed, and Embase were searched up to February 12, 2024. Review Manager 5.3 was used. The relative risk (RR) and 95% confidence interval were evaluated for dichotomous data. Continuous data were assessed using the mean difference and 95% confidence interval.

RESULTS

Nine studies comparing ACDF with ZPAS versus PC for 3-level contiguous cervical degenerative disease were included. The intraoperative blood loss and operation time in ZPAS were significantly less than those in PC. The subsidence rate, loss of cervical alignment, fusion segmental height, and intervertebral disc height were significantly greater in ZPAS than in PC. The cervical alignment and dysphagia rate within 6 months were significantly lower in ZPAS than in PC. The ASD of ZPAS was significantly lower than that of PC according to the sensitivity analysis when 1 study was excluded. No significant differences were identified in the other aspects.

CONCLUSIONS

Both ACDF with ZPAS and PC were safe and effective procedures. PC was associated with increased surgical trauma. The ZPAS could better decrease the incidence of ASD and dysphagia. ZPAS was also accompanied by high subsidence rate and poor cervical alignment.

Do modic changes affect the fusion rate in spinal interbody fusion surgery? A systematic review and network meta-analysis

OBJECTIVE

To compare the fusion rates of spinal interbody fusion in patients with modic changes (MCs).

METHODS

This meta-analysis was registered at PROSPERO, and the project number was CRD42024538023. This network meta-analysis was conducted according to the PRISMA 2020 statement. The PubMed, Embase, Web of Science Core Collection, ClinicalTrials.gov and Cochrane Library databases were searched from inception to March 28, 2024 for potential studies. STATA 13.0 and Review Manager 5.3 were used to perform the meta-analysis.

RESULTS

Seven studies with a total of 1162 patients or segments assigned to four groups according to MCs grade were identified. The fusion rate in the non-modic changes (NMCs) was significantly greater than that in the MCs at the 3-month (p = 0.0001) and 6-month (p = 0.002) follow-ups. No significant difference was detected in the fusion rate at 12-month (p = 0.34) and final follow-ups (p = 0.41). No significant difference was found in cervical fusion (p = 0.88) or transforaminal lumbar interbody fusion (TLIF) (p = 0.51). The fusion rate of NMCs was significantly greater than that of MCs in posterior lumbar interbody fusion (PLIF) (p < 0.00001). No significant differences were identified among the four groups in the overall comparison, cervical fusion or TLIF subgroups. The fusion rate in the NMCs was significantly greater than that in the MCs-2 and MCs-3 in the PLIF.

CONCLUSION

MCs decreased the fusion rate at the 3- and 6-month follow-ups. MCs-2 and MCs-3 decrease the fusion rate in PLIF.

Biomechanical comparison of static and dynamic cervical plates in terms of the bone fusion, tissue degeneration, and implant behavior

INTRODUCTION

Using an anterior cervical fixation device in the anterior cervical discectomy and fusion (ACDF) has evolved to various systems of static and dynamic cervical plates (SCP and DCP). Dynamic cervical plates have been divided into three categories: the rotational (DCP-R), translational (DCP-T), and hybrid (DCP-H) joints. However, little studies have been devoted to systematically investigate the biomechanical differences of dynamic cervical plates.

MATERIALS AND METHODS

The biomechanical tests of load-deformation properties and failure modes between the SCP and DCP systems are implemented first by using the UHMWPE blocks as the vertebral specimens. The CT-based C2-C7 model simulates the strategies of cervical plate in ACDF surgery is developed with finite-element analyses. One intact, one SCP and two DCP systems are evaluated for their biomechanical properties of bone fusion and tissue responses.

RESULTS

In the situation of biomechanical test, The mean values of the five ACDSP constructs are 393.6% for construct stiffness (p < 0.05) and 183.0% for the first yielding load (p < 0.05) less than those of the SCP groups, respectively. In the situation of finite-element analysis, the rigid-induced ASD is more severe for the SCP, followed by the DCP-H, and the DCP-R is the least.

DISCUSSION AND CONCLUSIONS

Considering the degenerative degree of the adjacent segments and osteoporotic severity of the instrumented segments is necessary while using dynamic system. The mobility and stability of the rotational and translational joints are the key factors to the fusion rate and ASD progression. If the adjacent segments have been degenerative, the more flexible system can be adopted to compensate the constrained mobility of the ACDF segments. In the situation of the osteoporotic ACDF vertebrae, the stiffer system is recommended to avoid the cage subsidence.

Anterior cervical discectomy and fusion with a dynamic translational plating versus a rigid carbon fiber reinforced PEEK plating system - a comparison study of radiographic parameters

PURPOSE

In this study the authors compare the radiographic findings of patients undergoing 1-3 level ACDF a rigid CFRP plate and a translational titanium plate system with a focus on radiographic alignment.

MATERIAL AND METHODS

A retrospective review 70 consecutive patients undergoing a 1 to 3 level ACDF for cervical spondylosis was conducted. 2 groups depending on the cervical plating system were created including 38 patients in group 1 (dynamic plate) and 32 in group 2 (rigid CFRP plate). Plain neutral radiographs preoperatively, immediately after surgery and at most recent follow-up were used to assess parameters on sagittal alignment, fusion height, adjacent segment ossification (ASO), fusion rate and implant failure.

RESULTS

There were no significant differences between groups preoperatively. Both groups had a more than 12 months follow-up (p = 0.327). Improvement of C2-7 lordosis was seen in both groups but only in group 1 it reached statistical significance at final follow-up. Significant improvement in sagittal segmental alignment was noted in both groups following surgery. A significant sagittal correction of 5.5 ± 9.1 degrees (p = 0.002) was maintained through follow-up only in group 2. No significantly different was seen for segmental fusion rates and loss of fusion height. There were no instances of implant failure within both groups. Worsening of ASO was 20% for both groups.

CONCLUSION

ACDF allows for correction and maintenance of cervical alignment. Rigid rigid plate appears more effective at maintaining segmental lordotic correction. The fusion rate and implant failure was not different for both groups.

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.

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.

Follow-up of a new titanium cervical plate for fusion of the cervical spine

Cervical plates are in use since the 1990ies for anterior cervical discectomy and fusion (ACDF). The latest step in development was a dynamic plate that allows sliding of the screws facilitating the natural settling of the bone after surgery. We investigated the clinical and radiological results of such a dynamic plate in a patient cohort that underwent single or multi-level ACDF for various cervical degenerative indications, including revision cases, from 2014 to 2019. Clinical and radiological outcome were assessed in 60 eligible patients after a mean of 2.9 years. The assessed neck disability index (NDI), and the visual analogue scale (VAS) of neck and arm pain show comparable results to the literature of ACDF, and specifically other plate designs. Forty-eight Adverse and Serious Adverse Events do not show a link to the product used. Clinical and radiological outcomes of ACDF with dynamic, third generation cervical plates show comparable results to the literature. Careful reporting of all Adverse Events revealed a variety of concomitant diseases, but could not be correlated to the implant used.

Hybrid fixation versus conventional cage-plate construct in 3-level ACDF: Introduce the "seesaw theory" of stand-alone cage

STUDY DESIGN

A retrospective study.

BACKGROUND

Conventional cage-plate construct (CCP) was widely used in anterior cervical discectomy and fusion (ACDF), but the rigid fixation limits the motion of fused segments. Self-locking stand-alone cage (SSC) was an alternative for ACDF procedures and showed several superiorities. However, the effect of hybrid fixation in 3-level ACDF remains unknown.

OBJECTIVE

To assess the clinical and radiological outcomes of hybrid fixation with SSC and CCP against conventional CCP in 3-level ACDF.

METHOD

A retrospective review of patients who underwent 3-level ACDF at Renji Hospital between January 2018 and December 2019 was performed. Eighty-three patients met the inclusion and exclusion criteria and were stratified into 2 groups based on the fixation methods. The clinical outcomes, functional outcomes, and radiological parameters were collected and analyzed.

RESULTS

No significant difference was observed between the two groups in the mean age, sex, body mass index, hospital stay, and duration of follow-up. The postoperative C2-7 Cobb angle in the CCP group was significantly greater than that in the hybrid group. The rate of cervical proximal junctional kyphosis (CPJK) in the hybrid group was significantly lower than that in the CCP group. The CCP group suffered significantly higher rates of adjacent segment degeneration (ASD) than the hybrid group at 2 years postoperatively. Moreover, the incidence of postoperative dysphagia was lower in the hybrid group. No significant differences were observed in JOA and NDI scores between the two groups.

CONCLUSION

The hybrid fixation achieved comparable clinical outcomes against CCP fixation, indicating that hybrid fixation is an alternative procedure in 3-level ACDF.

Bone resorption of vertebral bodies at the operative segment after prevail cervical interbody fusion: A case report

BACKGROUND

We report an interesting case of bone resorption of vertebral bodies at the operative segment after Peek Prevail cervical interbody fusion. Instability of cervical vertebrae is likely to occur due to increased stress in Peek Prevail implant body for bone resorption. The finite element analysis was used to clarify the biomechanical effects of bone resorption and stress distribution in Peek Prevail implant body.

METHODS

We reported the case of a 48-year-old male patient who underwent Peek Prevail cervical interbody fusion and exhibited bone resorption 1 month after the surgery in X-ray of cervical vertebra. The degree of bone resorption was aggravated 2 months after surgery. Bone resorption in 3 months was similar to that in 2 months. We established a 3D reconstruction of the surgical segment in this case using Mimics software (vision 20.0) to generate basic boss resorption model. We simulated models of bone resorption using Ansys 17.0. The stress distribution of the contact surface between the screw and bone was analyzed under 6 conditions: flexion, extension, left and right flexion, and left and right rotation.

RESULTS

The loading conditions affected the stress distribution in the implant body. When bone resorption occurred, the stress distribution of the contact surface between screw and bone focus in the tip of the screw increased sharply.

CONCLUSION

Bone resorption of vertebral bodies in the operative segment may be a potential complication after Peek Prevail cervical interbody fusion. Great attention must be paid when bone resorption was occurred in order to avoid screw loosening before vertebral fusion.

Uncovertebral Joint Fusion Versus End Plate Space Fusion in Anterior Cervical Spine Surgery: A Prospective Randomized Controlled Trial

BACKGROUND

The uncovertebral joint is a potential region for anterior cervical fusion. Currently, we are aware of no clinical trials on human uncovertebral joint fusion (UJF). The purpose of this study was to compare the time it took to achieve osseous union/fusion and the clinical efficacy of UJF to end plate space fusion (ESF)-i.e., traditional anterior cervical discectomy and fusion (ACDF)-in anterior cervical surgery.

METHODS

Patients with single-level cervical spondylosis were recruited from April 2021 through October 2022 and randomly divided into the UJF and ESF groups, with 40 patients in each group. Autologous iliac bone was used for bone grafting in both groups. The primary outcome was the early fusion rate at 3 months postoperatively. Secondary outcomes included the prevalence of complications and patient-reported outcome measures (PROMs), including the Japanese Orthopaedic Association (JOA) score, Neck Disability Index (NDI), and visual analog scale (VAS) scores for arm and neck pain.

RESULTS

A total of 74 patients (92.5%) with an average age of 49.8 years (range, 26 to 65 years) completed the trial and were included in the analysis. There was no significant difference between the 2 groups at baseline. The operative duration and intraoperative blood loss were also comparable between the 2 groups. The fusion rate in the UJF group was significantly higher than that in the ESF group at 3 months (66.7% compared with 13.2%, p < 0.0001) and 6 months (94.1% compared with 66.7%, p = 0.006) after the operation. No significant difference was found in the fusion rate between the 2 groups 12 months postoperatively. Overall, the PROMs significantly improved after surgery in both groups and did not differ significantly between the groups at any follow-up time point. The prevalence of complications was not significantly different between the 2 groups.

CONCLUSIONS

In our study of anterior cervical fusion surgery, we found that the early fusion rate after UJF was significantly higher than that after ESF.

LEVEL OF EVIDENCE

Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

Characteristics of Postoperative C5 Palsy Following Anterior Decompression and Fusion Surgery for Cervical Degenerative Disorders: Trends Associated with Advancements in Surgical Technique

OBJECTIVE

To investigate trends in the characteristics of postoperative C5 palsy following anterior decompression and fusion associated with advancements in this surgical procedure to treat cervical degenerative disorders.

METHODS

We included 801 consecutive patients who underwent anterior decompression and fusion for cervical degenerative disorders from 2006 to 2019 and investigated the incidence, onset, and prognosis of C5 palsy. In addition, we compared the incidence of C5 palsy with that found in our previous investigation.

RESULTS

The cases of 42 (5.2%) patients were complicated by C5 palsy. For patients with ossification of the longitudinal ligament (OPLL), 22 (12.4%) of 177 were complicated with C5 palsy, and the incidence was significantly higher than that in patients without OPLL (20 [3.2%] of 624, P < 0.01). The incidence of C5 palsy in patients without OPLL was significantly lower than that found in our previous investigation (P < 0.01). The incidence of C5 palsy in patients that required contiguous multilevel corpectomy was significantly higher in patients that required within a single corpectomy (P < 0.01). At 1-year follow-up, muscle strength in 3 (6.1%) of 49 limbs had not improved sufficiently.

CONCLUSIONS

With advancements in surgical techniques which allowed necessary and sufficient spinal cord decompression and avoided unnecessary corpectomy, the incidence of C5 palsy in patients without OPLL was decreased significantly. By contrast, for patients with OPLL, the incidence of C5 palsy was similar to the incidence found previously, perhaps because a broad and contiguous multilevel corpectomy was usually needed to decompress the spinal cord sufficiently.

Comparison of Single-level Cervical Radiculopathy Outcomes Between Posterior Endoscopic Cervical Decompression and Anterior Cervical Discectomy and Fusion: Mid-term Results

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

To investigate the mid-term results and technical possibilities of posterior endoscopic cervical decompression (PECD) in the treatment of cervical radiculopathy.

SUMMARY OF BACKGROUND DATA

PECD has been used in the treatment of cervical radiculopathy for the past decades; there is a paucity of studies directly comparing its outcomes with anterior cervical discectomy and fusion (ACDF) for patients with single-level cervical radiculopathy.

PATIENTS AND METHODS

From January 2016 to December 2018, clinical and radiologic data of 42 patients were collected. Patients were followed for a mean of 40.6 months (range: 30-54 mo) after surgery. Changes in cervical lordosis and degeneration of adjacent segments were analyzed. Dysphagia was assessed using the Bazaz score, and clinical outcomes were analyzed using the Neck Disability Index and visual analog scoring system.

RESULTS

There were no significant differences in neurological outcomes between the two groups. Significant between-group differences in postoperative dysphagia were observed ( P < 0.05). There were significant differences in postoperative segmental Cobb angles and disc height between the two groups ( P < 0.05). Degenerative changes in the adjacent segments occurred in 5 patients in the ACDF group and 1 patient in the PECD group ( P < 0.05); no revision surgery was needed.

CONCLUSIONS

Clinical outcomes of PECD for patients with unilateral radiculopathy were satisfactory. On the premise of a strict selection of indications, we consider this technique to be a safe supplement and alternative to ACDF for patients with unilateral cervical radiculopathy. Longer follow-up periods are required to confirm these observations.

Outcomes of different zero-profile spacers in the treatment of two-level cervical degenerative disk disease

PURPOSE

The purpose of this study was to analyze the clinical and radiological outcomes of two different zero-profile spacers (ROI-C and anchor-C) in contiguous two-level ACDF for CDDD patients.

METHODS

We retrospectively analyzed patients who underwent contiguous two-level ACDF due to CDDD between January 2015 and December 2020 in our hospital. Patients who received ROI-C and anchor-C were included as the study groups, and those who underwent plate-cage construct (PCC) were included as the control group. The primary outcome measures were radiographical parameters, and the secondary outcome measures were dysphagia, JOA scores and VAS scores for these patients.

RESULTS

A total of 91 patients were enrolled in the study; there were 31, 21 and 39 patients in the ROI-C, anchor-C and PCC groups, respectively. The mean follow-up duration was 24.52 months (range, 18-48 months) in the ROI-C group, 24.38 months (range, 16-52 months) in the anchor-C group and 25.18 months (range, 15-54 months) in the PCC group. The loss of the intervertebral space height and cage subsidence rate in the ROI-C group were significantly higher than those in the anchor-C group and PCC group at the final follow-up (P < 0.05). The ROI-C group showed a lower incidence of adjacent segment degeneration than the anchor-C group and PCC group, but the difference was not significant. The fusion rates were not different among these three groups. The early dysphagia rate was significantly lower in the patients with zero-profile spacers than in the PCC group (P < 0.05), but the difference was not significant at the last follow-up. No relevant differences were found in the JOA scores and VAS scores.

CONCLUSIONS

Zero-profile spacers showed promising clinical outcomes in CDDD patients having contiguous two-level ACDF. However, ROI-C resulted in a higher intervertebral space height loss and a higher cage subsidence rate than anchor-C during the follow-up.

Zero-P and ROI-C implants versus traditional titanium plate with cage to treat cervical spondylotic myelopathy: clinical and radiological results with 5 years of follow-up

BACKGROUND

Anterior cervical discectomy and fusion (ACDF) is the gold standard for treating cervical spondylotic myelopathy (CSM). While implanting plates in ACDF may increase the risk of complications. Zero-P and ROI-C implants have been gradually applied for CSM.

METHODS

150 patients with CSM were retrospectively analyzed from January 2013 to July 2016. Group A consisted of 56 patients who received traditional titanium plates with cage. 94 patients underwent ACDF using zero-profile implants and were divided into 50 patients with the Zero-P device (Group B) and 44 with the ROI-C device (Group C). Related indicators were measured and compared. The clinical outcomes were evaluated by JOA, VAS, and NDI scores.

RESULTS

Compared with group A, group B and C had a less blood loss and shorter operation time. The JOA and VAS scores improved significantly from pre-operative to 3 months postoperative and last follow-up in three groups. The cervical physiological curvature and segmental lordosis at final follow-up were higher than that of pre-operation (p < 0.05). Dysphagia rate, adjacent level degeneration rate, and Osteophyma rate was the highest in group A (p < 0.05). The bone graft fusion was achieved at the final follow-up in three groups. There were no statistical significance in fusion rate and subsidence rate among the three groups.

CONCLUSIONS

ACDF with Zero-P or ROI-C implants can also obtain satisfactory clinical outcomes compared to traditional titanium plate with cage after 5 years follow-up. The zero-profile implant devices carry a simple operation, short operation time, less intraoperation blood loss, and incidence of dysphagia.

Is anterior cervical plating necessary for cage constructs in anterior cervical discectomy and fusion surgery for cervical degenerative disorders? Evidence-based on the systematic overview of meta-analyses

STUDY DESIGN

Systematic review of meta-analyses.

OBJECTIVE

To perform a systematic review of meta-analyses to compare the clinical and radiological outcomes following anterior cervical discectomy and fusion with stand-alone cage (SAC) and anterior cervical cage-plate constructs (ACCPC).

METHODS

The systematic overview was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and reported as per Cochrane Handbook for Systematic Reviews of Interventions following the methodology described in reporting Overview of reviews.

RESULTS

Based on the available level-1 evidence, SAC offers significantly better benefits over ACCPC, in terms of shorter operative time (p < 0.00001; I2 = 0%), lower blood loss (p = 0.01; I2 = 0%), lesser rates of post-operative dysphagia (p = 0.02; I2 = 0%), reduced overall expenditure (p = 0.001) and long-term adjacent segment degeneration (ASD)/anterior longitudinal ligament ossification (ALO; p = 0.0003; I2 = 0%). There is no significant difference between the two constructs with regard to fusion rates, functional outcome scores, follow-up radiological sagittal alignment parameters or cage subsidence.

CONCLUSION

Based on the available evidence, SAC constructs in ACDF reduce blood loss, decreases operative time, mitigates post-operative dysphagia, lessens hospital-related expenditure and minimises long-term ASD rates.

Single-Stage Posterior Approach for Multilevel Cervical Ossification of the Posterior Longitudinal Ligament With K-line (-) Using Thick Cervical Pedicle Screw System: A Technical Note and Preliminary Results

STUDY DESIGN

Technical note, retrospective case series.

OBJECTIVE

The optimal surgical strategy for multilevel cervical ossification of the posterior longitudinal ligament (OPLL) with a negative kyphosis line (K-line (-)) remains controversial. We present a novel single-stage posterior approach that converts the K-line from negative to positive in patients with multilevel cervical OPLL, using a posterior thick cervical pedicle screw (CPS) system and report the procedure's outcomes and feasibility.

METHODS

Twelve consecutive patients with multilevel cervical OPLL and K-line (-) underwent single-stage posterior thick CPS fixation, with laminectomy and foraminal decompression. A pre-bent rod was installed to convert the K-line from negative to positive. Radiographic parameters, including the extent and occupying ratio of OPLL and the C2-C7 angle, were examined. CPS accuracy was assessed using computed tomography. The Japanese Orthopaedic Association (JOA) and visual analog scale (VAS) scores were analyzed. Quality of life was assessed using the Neck Disability Index (NDI). The mean OPLL extent was 5 vertebral body levels, and posterior decompression was performed on 4.2 segments.

RESULTS

The average C2-C7 angle and the occupying ratio of OPLL improved from -9.0° to 14.3° and from 63% to 33%, respectively. The preoperative JOA, VAS, and NDI scores significantly improved from 8.4 to 13.3, from 7.1 to 2.2, and from 21.9 to 9.3, respectively. The K-line was converted from negative to positive in all cases. No severe complications were identified.

CONCLUSION

Single-stage posterior surgery with a thick CPS system may be a reliable and effective treatment for multilevel cervical OPLL and K-line (-).

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.

Clinical and radiological comparison of the zero-profile anchored cage and traditional cage-plate fixation in single-level anterior cervical discectomy and fusion

BACKGROUND

The aim of this study was to compare the clinical outcomes and radiographic parameters of the zero-profile anchored cage and traditional cage-plate fixation in single-level anterior cervical discectomy and fusion (ACDF).

METHODS

Between January 2016 and November 2018, a total of 68 patients with degenerative cervical spondylosis who underwent single-level ACDF were evaluated in this retrospective study. Thirty-five patients were treated with the zero-profile anchored cage (Zero-P group), and 33 patients were treated with the traditional cage-plate fixation (Cage group). The two groups were compared in reference to clinical outcomes and radiographic parameters.

RESULTS

The mean operation time in the Zero-P group was significantly shorter than that in the Cage group. The incidence of postoperative dysphagia in the Cage group was higher than that in the Zero-P group at 3 months and 12 months postoperatively. No bony spurs were found in the Zero-P group, whereas 5 patients in the Cage group developed bony spurs. There were no statistically significant differences between the two groups in the JOA scores, VAS scores, NDI scores, C2-7 Cobb angles, segmental Cobb angles, total interbody height or fusion rates at 3 months or 12 months postoperatively.

CONCLUSION

In this study, both the zero-profile anchored cage and traditional cage-plate fixation were demonstrated to be effective and safe strategies. Given the lower incidence of dysphagia and degenerative changes, zero-profile anchored cage is a good option.

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.

New anterior controllable antedisplacement and fusion surgery for cervical ossification of the posterior longitudinal ligament: a biomechanical study

OBJECTIVE

The traditional anterior approach for multilevel severe cervical ossification of the posterior longitudinal ligament (OPLL) is demanding and risky. Recently, a novel surgical procedure-anterior controllable antedisplacement and fusion (ACAF)-was introduced by the authors to deal with these problems and achieve better clinical outcomes. However, to the authors' knowledge, the immediate and long-term biomechanical stability obtained after this procedure has never been evaluated. Therefore, the authors compared the postoperative biomechanical stability of ACAF with those of more traditional approaches: anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF).

METHODS

To determine and assess pre- and postsurgical range of motion (ROM) (2 Nm torque) in flexion-extension, lateral bending, and axial rotation in the cervical spine, the authors collected cervical areas (C1-T1) from 18 cadaveric spines. The cyclic fatigue loading test was set up with a 3-Nm cycled load (2 Hz, 3000 cycles). All samples used in this study were randomly divided into three groups according to surgical procedures: ACDF, ACAF, and ACCF. The spines were tested under the following conditions: 1) intact state flexibility test; 2) postoperative model (ACDF, ACAF, ACCF) flexibility test; 3) cyclic loading (n = 3000); and 4) fatigue model flexibility test.

RESULTS

After operations were performed on the cadaveric spines, the segmental and total postoperative ROM values in all directions showed significant reductions for all groups. Then, the ROMs tended to increase during the fatigue test. No significant crossover effect was detected between evaluation time and operation method. Therefore, segmental and total ROM change trends were parallel among the three groups. However, the postoperative and fatigue ROMs in the ACCF group tended to be larger in all directions. No significant differences between these ROMs were detected in the ACDF and ACAF groups.

CONCLUSIONS

This in vitro biomechanical study demonstrated that the biomechanical stability levels for ACAF and ACDF were similar and were both significantly greater than that of ACCF. The clinical superiority of ACAF combined with our current results showed that this procedure is likely to be an acceptable alternative method for multilevel cervical OPLL treatment.

Pseudarthrosis of the Cervical Spine

Pseudarthrosis of the cervical spine represents a common and challenging problem for spine surgeons. Rates vary greatly from as low as 0%-20% to >60% and depend heavily on patient factors, approach, and number of levels. While some patients remain asymptomatic from pseudarthrosis, many require revision surgery due to instability, continued neck pain, or radiculopathy/myelopathy. We aimed to provide a practical, narrative review of cervical pseudarthrosis to address the following areas: (1) definitions, (2) incidence, (3) risk factors, (4) presentation and workup, (5) treatment decision-making, and (6) postoperative care. It is our hope the current review provides a concise summary for how to diagnose and treat challenging cervical nonunions.

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.

Comparative Analysis of Cage Subsidence in Anterior Cervical Decompression and Fusion: Zero Profile Anchored Spacer (ROI-C) vs. Conventional Cage and Plate Construct

Background: Anterior cervical discectomy and fusion (ACDF) has been widely performed to treat cervical generative diseases. Cage subsidence is a complication after ACDF. Although it is known that segmental kyphosis, acceleration of adjacent segmental disease, and restenosis may occur due to cages subsidence; however detailed research comparing zero-profile cages (ROI-C) and conventional plate and cage construct (CPC) on cage subsidence has been lacking.

Objective: The objectives of this study was to compare the rate of postoperative cage subsidence between zero profile anchored spacer (ROI-C) and conventional cage and plate construct (CPC) and investigate the risk factors associated with cage subsidence following ACDF.

Methods: Seventy-four patients with ACDF who received either ROI-C or CPC treatment from October 2013 to August 2018 were included in this retrospective cohort study. Clinical and radiological outcomes and the incidence of cage subsidence at final follow up-were compared between groups. All patients were further categorized into the cage subsidence (CS) and non-cage subsidence (NCS) groups for subgroup analysis.

Results: The overall subsidence rate was higher in the ROI-C group than in the CPC group (66.67 vs. 38.46%, P = 0.006). The incidence of cage subsidence was significantly different between groups for multiple-segment surgeries (75 vs. 34.6%, P = 0.003), but not for single-segment surgeries (54.55 vs. 42.30%, P = 0.563). Male sex, operation in multiple segments, using an ROI-C, and over-distraction increased the risk of subsidence. Clinical outcomes and fusion rates were not affected by cage subsidence.

Conclusion: ROI-C use resulted in a higher subsidence rate than CPC use in multi-segment ACDF procedures. The male sex, the use of ROI-C, operation in multiple segments, and over-distraction were the most significant factors associated with an increase in the risk of cage subsidence.

Cervical fusion for treatment of degenerative conditions: development of appropriate use criteria

BACKGROUND CONTEXT

High quality evidence is difficult to generate, leaving substantial knowledge gaps in the treatment of spinal conditions. Appropriate use criteria (AUC) are a means of determining appropriate recommendations when high quality evidence is lacking.

PURPOSE

Define appropriate use criteria (AUC) of cervical fusion for treatment of degenerative conditions of the cervical spine.

STUDY DESIGN/SETTING

Appropriate use criteria for cervical fusion were developed using the RAND/UCLA appropriateness methodology. Following development of clinical guidelines and scenario writing, a one-day workshop was held with a multidisciplinary group of 14 raters, all considered thought leaders in their respective fields, to determine final ratings for cervical fusion appropriateness for various clinical situations.

OUTCOME MEASURES

Final rating for cervical fusion recommendation as either "Appropriate," "Uncertain" or "Rarely Appropriate" based on the median final rating among the raters.

METHODS

Inclusion criteria for scenarios included patients aged 18 to 80 with degenerative conditions of the cervical spine. Key modifiers were defined and combined to develop a matrix of clinical scenarios. The median score among the raters was used to determine the final rating for each scenario. The final rating was compared between modifier levels. Spearman's rank correlation between each modifier and the final rating was determined. A multivariable ordinal regression model was fit to determine the adjusted odds of an "Appropriate" final rating while adjusting for radiographic diagnosis, number of levels and symptom type. Three decision trees were developed using decision tree classification models and variable importance for each tree was computed.

RESULTS

Of the 263 scenarios, 47 (17.9 %) were rated as rarely appropriate, 66 (25%) as uncertain and 150 (57%) were rated as appropriate. Symptom type was the modifier most strongly correlated with the final rating (adjusted ρ2 = 0.58, p<.01). A multivariable ordinal regression adjusting for symptom type, diagnosis, and number of levels and showed high discriminative ability (C statistic = 0.90) and the adjusted odds ratio (aOR) of receiving a final rating of "Appropriate" was highest for myelopathy (aOR, 7.1) and radiculopathy (aOR, 4.8). Three decision tree models showed that symptom type and radiographic diagnosis had the highest variable importance.

CONCLUSIONS

Appropriate use criteria for cervical fusion in the setting of cervical degenerative disorders were developed. Symptom type was most strongly correlated with final rating. Myelopathy or radiculopathy were most strongly associated with an "Appropriate" rating, while axial pain without stenosis was most associated with "Rarely Appropriate."

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.

Use of zero-profile device for contiguous three-level anterior cervical discectomy and fusion: comparison with cage and plate construct

OBJECTIVE

The aim of this study was to compare a traditional cervical cage with a zero-profile (ZP) fixation device in patients who underwent three-level anterior cervical decompression and fusion (ACDF) in terms of patient-reported outcomes (visual analog scale [VAS], Japanese Orthopaedic Association [JOA], and Neck Disability Index [NDI] scores), radiographic findings (sagittal alignment 2 years after surgery and likelihood of fusion), and complications.

METHODS

This study was a retrospective case series. Between January 2012 and December 2016, 58 patients with cervical spondylotic myelopathy (CSM) who required three-level ACDF procedures, as identified by spinal surgeons, were treated with three-level ACDF and an anterior cage-plate construct (ACPC) (n = 38) or a three-level stand-alone ZP device (n = 20). On the basis of patient choice, patients were divided into two groups (ACPC group and ZP group). All patients completed a minimum of 2 years of follow-up. Patient-reported outcome scores included VAS, JOA, and NDI scores. The radiographic findings included sagittal alignment and likelihood of fusion 2 years after surgery. Data related to patient-reported outcomes and sagittal alignment were collected preoperatively, postoperatively, and at the final follow-up. Intraoperative and postoperative complications were also documented and analyzed.

RESULTS

The clinical outcomes, including VAS, JOA, and NDI scores, showed improvement in both groups, and no significant difference was observed between the two groups. Sagittal alignment and height of the fused segments were restored in all patients. However, the authors found no differences between the ZP and ACPC groups, and the groups exhibited similar fusion rates. The authors found no differences in complications, including dysphagia, adjacent-segment degeneration, and postoperative hematoma, between the groups.

CONCLUSIONS

Use of ZP implants yielded satisfactory long-term clinical and radiological outcomes that were similar to those of the standard ACPC. Additionally, the rates of complications between the groups were not significantly different. Although the best surgical option for multilevel CSM remains controversial, the results of this work suggest that ACDF with the ZP device is feasible, safe, and effective, even for multilevel CSM.

Cervical spine alignment and clinical outcomes after multilevel anterior cervical decompression and fusion with or without plate: A minimal 5-year follow-up of a CONSORT-compliant article

It was reported imperative on cervical sagittal alignment reconstruction after anterior multilevel procedures with self-locked stand-alone cage (SSC) or anterior cage-with-plate (ACP) system multilevel while there was little knowledge about the relationship on cervical alignment and clinical outcomes.To identify the importance of cervical sagittal alignment after 3-level anterior cervical discectomy and fusion on cervical spondylotic myelopathy with SSC and ACP system.Seventy-seven patients with SSC system (SSC group) and 52 cases with ACP system (ACP group) from February 2007 to September 2013 were enrolled with well-matched demographics. Cervical alignment included C2-7 lordosis (CL), operated-segment cervical lordosis (OPCL), upper and lower adjacent-segment cervical lordosis, range of motion of upper and lower adjacent segment at preoperation, immediate postoperation, and the final follow-up. Clinical outcomes contained the neck disability index (NDI), the Japanese Orthopaedic Association (JOA) score, visual analogous scale (VAS) of arm and neck and adjacent segment degeneration (ASD). Patients were then divided into CL improved subgroup (IM subgroup) and non-improved subgroup (NIM subgroup).There were improvements on CL and OPCL in both groups. The change of CL and OPCL larger in ACP group (P < .05) but upper adjacent-segment cervical lordosis/lower adjacent-segment cervical lordosis and range of motion of upper adjacent segment/range of motion of lower adjacent segment were of no significance. NDI, JOA, and VAS got improvement in both groups at immediate postoperation and the final follow-up while ASD was in no difference between SSC and ACP group. A total of 80 patients (39 vs 41) acquired CL improvement with a larger population in ACP group. There were no differences on the rate of ASD, NDI, JOA, VAS, and their change between IM and NIM subgroup. The changes of CL were not correlated to NDI, JOA, VAS, and their change.SSC and ACP group both provide improved OPCL and efficacy on 3-level cervical spondylotic myelopathy with little impact on adjacent segment. The change of CL is not correlated to clinical outcomes.

Does Dynamic Anterior Plate Fixation Provide Adequate Stability for Traumatic Subaxial Cervical Spine Fractures at Mid-Term Follow-Up?

Background: It remains questionable if the treatment of cervical fractures with dynamic plates in trauma surgery provides adequate stability for unstable fractures with disco-ligamentous injuries. The primary goal of this study was to assess the radiological and mid-term patient-reported outcome of traumatic subaxial cervical fractures treated with different plate systems. Patients and Methods: Patients, treated with anterior cervical discectomy and fusion (ACDF) between 2001 and 2015, using either a dynamic plate (DP: Mambo™, Ulrich, Germany) or a rigid locking plate (RP: CSLP™, Depuy Synthes, USA), were identified. For radiological evaluation, the sagittal alignment, the sagittal anterior translation and the bony consolidation were evaluated. After at least two years, the patient-reported outcome measures (PROM) were evaluated using the German Short-Form 36 (SF-36), Neck Disability Index (NDI) and the EuroQol in 5 Dimensions (EQ-5D) scores. Results: 33 patients met the inclusion criteria (DP: 13; RP:20). Twenty-six patients suffered from AO Type B or C fractures. Both the sagittal alignment and the sagittal translation could be sufficiently improved in both groups (p ≥ 0.05). No significant loss of reduction could be observed at the follow-up in both groups (p ≥ 0.05). Bony consolidation could be observed in 30 patients (DP: 12/13 (92%); RP: 18/20 (90%); (p ≥ 0.05)). In 20 patients, PROMs could be evaluated (follow-up: 71.2 ± 25.5 months). The whole cohort showed satisfactory PROM results (EQ-5D: 72.0 ± 4.9; SF-36 PCS: 41.9 ± 16.2, MCS: 45.4 ± 14.9; NDI: 11.0 ± 9.1). without significant differences between the DP and RP group (p ≥ 0.05) Conclusion: The dynamic plate concept provides enough stability without a difference in fusion rates in comparison to rigid locking plates in a population that mostly suffered fragile fractures.

Fragility Analysis of Statistically Significant Outcomes of Randomized Control Trials in Spine Surgery: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

The aim of this study was to assess the robustness of statistically significant outcomes from randomized control trials (RCTs) in spine surgery using Fragility Index (FI) which is a novel metric measuring the number of events upon which statistical significance of the outcome depends.

SUMMARY OF BACKGROUND DATA

Many trials in Spine surgery were characterized by fewer outcome events along with small sample size. FI helps us identify the robustness of the results from such studies with statistically significant dichotomous outcomes.

METHODS

We conducted independent and in duplicate, a systematic review of published RCTs in spine surgery from PubMed Central, Embase, and Cochrane Database. RCTs with 1:1 prospective study design and reporting statistically significant dichotomous primary or secondary outcomes were included. FI was calculated for each RCT and its correlation with various factors was analyzed.

RESULTS

Seventy trials met inclusion criteria with a median sample size of 133 (interquartile range [IQR]: 80-218) and median reported events per trial was 38 (IQR: 13-94). The median FI score was 2 (IQR: 0-5), which means if we switch two patients from nonevent to event, the statistical significance of the outcome is lost. The FI score was less than the number of patients lost to follow-up in 28 of 70 trials. The FI score was found to positively correlated with sample size (r = 0.431, P = 0.001), total number of outcome events (r = 0.305, P = 0.01) while negatively correlated with P value (r = -0.392, P = 0.001). Funding, journal impact-factor, risk of bias domains, and year of publication did not have a significant correlation.

CONCLUSION

Statistically significant dichotomous outcomes reported in spine surgery RCTs are more often fragile and outcomes of the patients lost to follow-up could have changed the significance of results and hence it needs caution before transcending their results into clinical application. The addition of FI in routine reporting of RCTs would guide readers on the robustness of the statistical significance of outcomes. RCTs with FI ≥5 without any patient lost to follow-up can be considered to have clinically robust results.Level of Evidence: 1.

Pseudarthrosis in anterior cervical discectomy and fusion with a self-locking, stand-alone cage filled with hydroxyapatite: a retrospective study with clinical and radiological outcomes of 98 levels with a minimum 2-year follow-up

OBJECTIVE

The goal of this study was to evaluate the incidence of pseudarthrosis after the treatment of cervical degenerative disc disease (CDDD) with anterior cervical discectomy and fusion (ACDF) in which self-locking, stand-alone intervertebral cages filled with hydroxyapatite were used.

METHODS

The authors performed a retrospective cohort study of 49 patients who underwent 1- to 3-level ACDF with self-locking, stand-alone intervertebral cages without plates, with a minimum 2 years of follow-up. The following data were extracted from radiological and clinical charts: age, sex, time and type of pre- and postoperative signs and symptoms, pain status (visual analog scale [VAS]), functional status (Neck Disability Index [NDI]), history of smoking, bone quality (bone densitometry), and complications. Pseudarthrosis was diagnosed by a blinded neuroradiologist using CT scans. Clinical improvement was assessed using pre- and postoperative comparison of VAS and NDI scores. The Wilcoxon test for paired tests was used to evaluate statistical significance using a p value of < 0.05.

RESULTS

Three patients (6%) developed symptomatic pseudarthrosis requiring reoperation, with only 1 patient showing clinical worsening due to pseudarthrosis, while the other 2 with pseudarthrosis had associated disc disease at an adjacent level. The rate of symptomatic pseudarthrosis according to the number of operated levels was 0% for 1 level, 8.7% (2/23 patients) for 2 levels, and 7.7% (1/13 patients) for 3 levels. The total pseudarthrosis rate (including both symptomatic and asymptomatic patients) was 16.4%. Considering the clinical outcomes, there was a significant improvement of 75.6% in neck pain and 95.7% in arm pain, as well as a 64.9% improvement in NDI scores. Complications were observed in 18.4% of patients, with adjacent-level degenerative disease being the most prevalent at 14.3%.

CONCLUSIONS

ACDF with self-locking, stand-alone cages filled with a hydroxyapatite graft can be used for the surgical treatment of 1- to 3-level CDDD with clinical and radiological outcomes significantly improved after a minimum 2-year follow-up period. Comparative studies are necessary.

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.

Does Hybrid Surgery Improve Quality of Life in Multilevel Cervical Degenerative Disk Disease? Five-Year Follow-up Study

BACKGROUND

Patient satisfaction is becoming an increasing factor worthy of consideration when evaluating the surgical quality. The correlation between patient satisfaction and surgical outcomes 5 years after cervical hybrid surgery (HS), which incorporates anterior cervical decompression and fusion and cervical disk arthroplasty techniques in multilevel cervical degenerative disk disease, has not been evaluated.

METHODS

The aim of this study was firstly to analyze prospectively collected data from a sample of patients (n = 50) treated with cervical HS for selected cases of radiculopathy and myelopathy in order to evaluate pain levels of patients, using the Neck and Arm Pain scale as an expression of visual analog scale. Secondly, we aimed to evaluate health-related quality of life, via the short-form 36, Neck Disability Index, and Japanese Orthopedic Association score. Patients were followed up for more than 5 years. Intraoperative parameters, clinical features, and outcome scores were recorded. Radiologic investigations including disk height and changes in adjacent disk spaces were assessed.

RESULTS

Clinical improvements were observed in all outcomes; significant improvements on the Neck Disability Index, visual analog scale, short-form 36, and Japanese Orthopedic Association scores were maintained at 5 years (P < 0.05). The mean disk height resulted restored in all the cases. Temporary dysphagia was rarely observed (3%). No surgery for adjacent-level disease was required. There was no significant difference in the outcomes between radiculopathy and myelopathy groups (P > 0.05).

CONCLUSIONS

HS is an effective and safe procedure for the treatment of multilevel cervical degenerative disk disease. Such a surgical construct offers postoperative improvement on pain levels and health-related quality of life.

Novel Technique as a Revision Surgery for Failed Anterior Cervical Corpectomy and Fusion in the Treatment of Cervical Myelopathy Due to Ossification of the Posterior Longitudinal Ligament

OBJECTIVE

This article aimed to introduce a novel technique, the "seesaw technique," for failed anterior cervical corpectomy and fusion (ACCF) in the treatment of cervical ossification of the posterior longitudinal ligament.

METHODS

A patient who underwent ACCF 12 years ago and suffered gradually deteriorating neurologic function was referred to our institution. Preoperative imaging showed residual ossified mass at C5/6 level, causing compression to his spinal cord. He patient was treated by the seesaw technique. The main surgical procedures include removal of the plate and screws, removal of the osteophytes and diskectomy of C4/5, resection of the anterior part of C5 vertebral body, establishment of a transverse hinge at C7 vertebral body, installation of cervical plate and hoisting tool, and antedisplacement of C5 vertebral body and titanium mesh. Images were investigated before and after the procedure. The Japanese Orthopaedic Association score was used to evaluate his neurologic function, and surgery-related complications were also analyzed.

RESULTS

The patient acquired significant improvement of his neurologic function 2 days after the surgery, and he could walk by himself without assistance. Postoperative images showed his spinal canal was enlarged sufficiently and the compression at C5/6 level was also released. At 13 months follow-up, his Japanese Orthopaedic Association score increased from 9 before surgery to 14, with an improvement rate of 62.5%. No surgery-related complications were observed during the whole follow-up.

CONCLUSION

The seesaw technique provides satisfactory outcomes with wide enough decompression window and serves as a safe, effective surgical alternative for patients with failed ACCF.

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.

[Effect of zero-profile and self-locking intervertebral cage and plate-cage construct on maintenance of cervical curvature after anterior cervical surgery]

OBJECTIVE

To compare differences in the maintenance of cervical curvature after anterior cervical surgery between zero-profile and self-locking intervertebral cage and plate-cage construct (PCC).

METHODS

A clinical data of 100 patients with single-segment cervical disc herniation who were treated with anterior cervical discectomy and fusion were retrospectively analyzed between January 2015 and January 2016. Among them, 50 patients were treated with the zero-profile and self-locking intervertebral cage (group A) and 50 patients with the PCC (group B). There was no significant difference between the two groups in age, gender, bone mineral density, disease duration, operative segment, and preoperative visual analogue scale (VAS) score, Japanese Orthopaedic Association (JOA) score, C 2-7 cervical curvature, segmental Cobb angle, and adjacent vertebral height ( P>0.05). The operation time and intraoperative blood loss were recorded. The postoperative VAS and JOA scores were used to evaluate the clinical efficacy. The C 2-7 cervical curvature, segmental Cobb angle, and adjacent vertebral height were measured on lateral X-ray films, and the interbody fusion was evaluated according to Pitzen's criteria.

RESULTS

The operation time in group A was significantly shorter than that in group B ( t=2.442, P=0.021), but there was no significant difference in the intraoperative blood loss between the two groups ( t=0.812, P=0.403). All patients were followed up 24-36 months, with an average of 28.5 months. According to Pitzen's criteria for cervical interbody fusion, bone fusion achieved in both groups. The VAS score, JOA score, C 2-7 cervical curvature, segmental Cobb angle, and adjacent vertebral height of the two groups at 1 and 24 months after operation were significantly improved when compared with those before operation ( P<0.05). The C 2-7 cervical curvature, segmental Cobb angle, and adjacent vertebral height of group A at 24 months changed significantly compared with those at 1 month ( P<0.05). The other indexes of the two groups showed no significant difference between the different time points after operation ( P>0.05). There were significant differences in C 2-7 cervical curvature, segmental Cobb angle, and adjacent vertebral height between the two groups at 24 months after operation ( P<0.05); but there was no significant difference in the clinical indexes at 1 and 24 months and the imaging indexes at 1 month between the two groups ( P>0.05).

CONCLUSION

Compared with the PCC, the zero-profile and self-locking intervertebral cage can significantly shorten the operation time and obtain the same clinical efficacy, but the intervertebral height loss and secondary cervical curvature change after operation is more serious.

Correlation Between Different Interbody Grafts and Pseudarthrosis After Anterior Cervical Discectomy and Fusion Compared with Control Group: Systematic Review

BACKGROUND

Cervical spine degenerative disease is one of the main causes of myelopathy. Anterior cervical discectomy and fusion (ACDF) is the most common surgical procedure used to treat cervical myelopathy. Therefore, it is important to study pseudarthrosis rates after ACDF and correlate them with the graft used.

METHODS

We performed a systematic review to evaluate the relationship between pseudarthrosis after ACDF and the interbody graft used.

RESULTS

A total of 3732 patients were evaluated in 46 studies. The mean age of the included patients was 51.5 ± 4.18 years (range, 42-59.6 years). ACDF is most often perforemd as single-level surgery and the level most impaired is C5-C6. The use of titanium cages, zero profile, recombinant human bone morphogenetic protein 2, and carbon cages was seen as a protective factor for pseudarthrosis compared with the autograft group (control group); with an odds ratio of 0.29, 0.51, 0.03, and 0.3, respectively; the results were statistically relevant. The use of polyetheretherketone, poly(methyl methacrylate), and trabecular metal was a risk factor for development of pseudarthrosis compared with the control group, with an odds ratio of 1.7, 8.7, and 6.8, respectively; the results were statistically relevant. Radiologic follow-up was an important factor for the pseudarthrosis rate; paradoxically, a short follow-up (<1 year) had lower rates of pseudarthrosis and follow-up >2 years increased the chance of finding pseudarthrosis.

CONCLUSIONS

Different types of grafts lead to a significant difference in pseudarthrosis rates. Follow-up time is also an important factor that affects the rate of pseudarthrosis after ACDF.

Risk assessment of vertebral artery injury in anterior controllable antedisplacement and fusion (ACAF) surgery: a cadaveric and radiologic study

PURPOSE

We have introduced a novel surgery technique named anterior controllable antedisplacement and fusion (ACAF) for the treatment of ossification of the posterior longitudinal ligament. As reported, the satisfactory postoperative outcome can be attributed to the larger decompression width. However, it may associate with high prevalence of vertebral artery injury (VAI) theoretically. Thus, assessment of the vulnerability of vertebral artery in ACAF is of great importance.

METHODS

Computed tomographic scan data of 28 patients were retrospectively studied. Seven radiographic parameters were evaluated: uncinate process (UP) tips distance, transverse foramen (TF)-UP tips distance, TF-LWL (the ipsilateral limited wedging line) distance, the limited distance of lateral decompression, the maximum oblique angle of LWL, TF-LWG (the lateral wall of groove) distance, and width of groove. Eleven fresh cadaveric spines undergoing ACAF surgery were also studied. Two anatomic parameters were evaluated: width of groove and LWG-TF distance.

RESULTS

The UP tips distance increased from C3 to C6 and tended to be larger in males. The UP tip-TF distance and LWL-TF distance were smallest at C4, but both were larger than 2 mm. Maximum oblique angle decreased from C3 to C6. Postoperatively, both radiographic and cadaveric measurements showed the width of groove was larger than UP tips distance, but LWG-TF distance was larger than 2 mm in all levels.

CONCLUSION

UP can be used as anatomical landmarks to avoid VAI during ACAF surgery. Radiographic and cadaveric measurements verified the safety of ACAF surgery, even for those cases with wedging and lateral slotting.

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.

The use of anterior cervical interbody spacer with integrated fixation screws for management of cervical disc disease

INTRODUCTION

Integrated cage and screw designs were introduced for anterior cervical discectomy and fusion (ACDF) and allegedly are superior to anterior plating due to their minimal anterior profile.

METHODS

A descriptive study was designed as a prospective case series of 25 patients (30 operated discs) with cervical disc disease treated with a zero-profile cage, and followed up for an average of 16 months (range 12 -18 months). Functional assessment was done with the Neck Disability Index (NDI) and Visual analog scale (VAS) scores for arm and neck pain. Furthermore, Nurick's classification system for myelopathy based on gait abnormalities was documented. Radiological fusion was confirmed with plain X-rays and when indicated with a CT scan at 12 months postoperatively. Dysphagia was classified according to the Bazaz criteria.

RESULTS

VAS for neck and arm pain, NDI, and Nurick Score immediately improved postoperatively and remained so at 12-month follow-up. Fusion was achieved in 19 patients (95%) at six months and in 20 patients (100%) of the single-level group at one year. At six months 80% (four patients) and at 12 months 100% (five patients) showed complete union in the double-level group. No evidence of cage subsidence was noted radiographically.

DISCUSSION

The favorable lordosis and fusion rates of the low-profile integrated device are consistent with ACDF using anterior plating. Additionally, improved pain and an acceptable rate of dysphagia support the use of integrated interbody spacers for use in ACDF procedures.

Can Self-Locking Cages Offer the Same Clinical Outcomes as Anterior Cage-with-Plate Fixation for 3-Level Anterior Cervical Discectomy and Fusion (ACDF) in Mid-Term Follow-Up?

Background

Self-locking stand-alone cages (MC+) and cage-with-pate fixation system are 2 different surgical methods used in anterior cervical discectomy and fusion (ACDF), but few systematic comparative studies comparing the 2 methods in treating multilevel cervical spondylotic myelopathy (MCSM) have been published.

Material/Methods

Sixty-two patients with MCSM who underwent multilevel ACDF were enrolled and completed at least a 3-year postoperative follow-up. The operative time, intra-operative blood loss, and clinical and radiological results were compared between the MC+ self-locking cages group and the cage-with-plate fixation group. Clinical parameters, including VAS for neck pain, Japanese Orthopedic Association (JOA) score, and neck disabled index (NDI), were evaluated. Surgical results according to Odom’s criteria and postoperative dysphagia status, C5 nerve root palsy, and loosening of the instrumentation were recorded. Postoperative radiological results, including fusion rates, fusion segmental Cobb’s angle (FSC), cervical lordosis, fusion segmental height (FSH), cage subsidence, and adjacent segment degeneration, were assessed.

Results

The VAS score, JOA score, and NDI score were significantly improved in both groups. However, the patients in the cage-with-plate group were more likely to have neck pain at the last follow-up. The cervical lordosis, FSC, and FSH showed significant correction immediately after surgery. The loss of the cervical lordosis and FSH were higher in the MC+ group.

Conclusions

We found that use of MC+ cages is safe and effective in treating MCSM, but for patients who require strong postoperative stabilization and maintaining the cervical alignment better, the cage-with-plate fixation may best.

Clinical and radiological outcomes of a cervical cage with integrated fixation

Cervical cages with integrated fixation have been increasingly used in anterior cervical discectomy and fusion (ACDF) to avoid complications associated with anterior cervical plates. The purpose of this paper is to provide 2-year follow-up results of a prospective study after implantation of a cervical cage with an integrated fixation system.This was a prospective multicenter outcome study of 90 patients who underwent ACDF with a cage with integrated fixation. Fusion was evaluated from computed tomography images (CT-images) by an independent laboratory at 2-year follow-up (FU). Clinical and radiological findings were recorded preoperatively and at FU visits and complications were reported.At 24 months, the fusion rate was 93.4%. All average clinical outcomes were significantly improved at 2 years FU compared to baseline: neck disability index (NDI) 18.9% vs 44.4%, visual analog scale (VAS) for arm pain 18.2 mm vs 61.9 mm, VAS for neck pain 23.9 mm vs 55.6 mm. Short form-36 (SF-36) scores were significantly improved. One case of dysphagia, which resolved within 12 months, and 1 reoperation for symptomatic pseudarthrosis were reported. Subsidence with no clinical consequence or reoperation was reported for 5/125 of the implanted cages (4%). There was also 1 case of per-operative vertebral body fracture that did not require additional surgery. Superior and inferior adjacent discs showed no significant change of motion at 2-year FU compared to baseline. Disc height index (DHI) and lordosis were enhanced and these improvements were maintained at 1 year.The ACDF using cages with an integrated fixation system demonstrated reliable clinical and radiological outcomes and a high interbody fusion rate. This rate is comparable to the rate reported in recent series using other implants with integrated fixation, but the present device had a lower complication rate.

Comparison between zero-profile spacer and plate with cage in the treatment of single level cervical spondylosis

BACKGROUND

Retrospective study of 68 patients of symptomatic cervical spondylosis who were treated by anterior cervical discectomy and fusion (ACDF).

OBJECTIVE

The purpose of this study was to compare the clinical and radiological outcomes of patients with single level cervical spondylosis using either zero-profile spacer (group A) or anterior cervical plate and cage (group B).

METHODS

Clinical and radiological data of 68 patients undergoing ACDF from C3-C7 were collected retrospectively. There were 35 patients with a mean age of 54.05 years who received treatment by zero-profile implant. A total of 33 patients with a mean age of 52.09 years underwent fusion by traditional plate with cage. Group A and group B were followed up for an average of 23.68 months and 24.39 months, respectively. Age, blood loss, and operation time were assessed. The clinical outcomes were evaluated by JOA and VAS score before and after surgery. In addition, incidence of dysphagia was recorded. The Cobb angle (from C2 to C7) change was measured on the lateral cervical spine radiographs.

RESULTS

There was no significant difference in terms of operation time and blood loss between two groups. The postoperative JOA significantly increased and the VAS decreased correspondently in both groups. The postoperative Cobb angle increased and showed statistical difference compared with preoperative Cobb angle in both groups. There was no significant difference between group A and group B in achieving clinical symptoms and radiograph improvement according to postoperative JOA, VAS and Cobb angle comparison. The incidence of postoperative dysphagia was lower in the group A than group B.

CONCLUSIONS

Our study suggests that the application of zero-p spacer can achieve similar clinical and radiological improvement compared with traditional plate and cage. Meanwhile, zero-p is superior to plate and cage with a lower incidence of postoperative dysphagia.

Risk Factors for Dysphagia After Anterior Cervical Spine Surgery

This study evaluated the risk factors for dysphagia after anterior cervical spine surgery by multidimensional analysis and investigated the predictive values of these risk factors for dysphagia. The patients underwent anterior cervical spine surgery and were followed for at least 6 months. Sex, age, tracheal mobility, smoking history, implant type, C3 anterior vertebral soft tissue swelling, narrowest esophageal distance before internal fixation, cervical curvature, operative time, occurrence of fusion, number of operative segments, and highest vertebral segment were recorded. Chi-square test and logistic regression were performed to analyze the predictive value of each dimension for dysphagia. A total of 158 patients were included in this study. The mean C3 anterior vertebral soft tissue swelling was 8.8±4.5 mm, the mean narrowest esophageal distance before internal fixation was 6.9±4.4 mm, and the mean operative time was 78.5±39.2 minutes. Chi-square test results showed that age 60 years and older, female sex, internal fixation with titanium plate/titanium mesh, narrowest esophageal distance before internal fixation of less than 5 mm, and 3 operative segments indicated a relatively high incidence of dysphagia. Logistic regression analyses showed that age, sex, implant type, narrowest esophageal distance before internal fixation, and number of operative segments were all risk factors predictive of postoperative dysphagia. The area under the receiver operating characteristic curve was 0.872. Age 60 years and older, female sex, internal fixation with titanium plate/titanium mesh, narrowest esophageal distance before internal fixation of less than 5 mm, and 3 operative segments were risk factors for dysphagia after anterior cervical surgery. The regression equation may be used to predict the occurrence of dysphagia. [Orthopedics. 2018; 41(1):e110-e116.].