Surgical Outcome of a Zero-profile Device Comparing with Stand-alone Cage and Anterior Cervical Plate with Iliac Bone Graft in the Anterior Cervical Discectomy and Fusion

A pragmatic single centre retrospective comparative review of complication profile between PEEK cages and Zero-P cage screw constructs

BACKGROUND

Anterior Decompression and Fusion (ACDF) is a common surgery recommended for symptomatic cervical degenerative disc disease after failed conservative care. There is no consensus on the choice of implants, and it varies between surgeons. This study aims to analyse the early complications following ACDF performed using a standalone cage versus a Zero-P (Cage Screw - (CS)) construct for patients with cervical degenerative disc disease.

METHODS

A total of 162 patients underwent an ACDF between August 2016 and July 2018. There were 83 patients (111 cervical disc levels) with standalone cage (SA) and 79 patients (111 cervical disc levels) with cage-screw (CS) fixation. There was no difference between the groups in terms of age, gender, and levels of surgery. The follow-up ranged from 2 months to 24 months. Complications, both clinical and radiological, were assessed between the groups.

RESULTS

Both the SA and Zero-P (CS) groups were subdivided into single and multilevel surgery. Complications encountered in the SA group were temporary swallowing problems 10, hoarseness of voice 3, cage migration 1, delayed union 1, Horner's syndrome 1, cage subsidence 2. In the CS group swallowing problems 4, hoarseness of voice 4, CSF leak 1, recurrent symptoms 1. The observed difference in the incidence of complications between the groups did not reach statistical significance. Univariate analysis between the groups did not show any difference in the improvement of cervical sagittal balance, fusion rate, subsidence, and complications encountered. Multivariate logistic regression analysis for complications showed no difference between the groups when assessed for smoking, gender, age, Charlson comorbidity index, levels of surgery, fusion status, Odom score, or the type of implant.

CONCLUSION

In this short-term study, the standalone (SA) cages showed no difference in their complication profile in comparison to a cage-screw construct for both single and multilevel ACDF. Standalone cages might be a cost-effective option without increased complication risks. Nevertheless, we propose a longer-term follow-up with a prospective randomized trial for further evaluation of this finding.

Complications With Demineralized Bone Matrix, Hydroxyapatite and Beta-Tricalcium Phosphate in Single and Two-Level Anterior Cervical Discectomy and Fusion Surgery

STUDY DESIGN

Systematic literature review.

OBJECTIVES

To analyze the evidence available reporting complications in single or two-level anterior cervical discectomy and fusion (ACDF) using a demineralized bone matrix (DBM), hydroxyapatite (HA), or beta-tricalcium phosphate (β-TCP).

METHODS

A systematic review of the literature using PubMed, EMBASE, Cochrane Library, and ClinicalTrials.gov databases was performed in August 2020 to identify studies reporting complications in one or two-level ACDF surgery using DBM, HA, or β-TCP. The study was reported following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines.

RESULTS

A total of 1857 patients were included, 981 male and 876 female, across 17 articles; 5 prospective, and 12 retrospectives. We noted heterogeneity among the included studies concerning the study design and combination of graft materials utilized in them. However, we noted a higher incidence of adjacent segment disease (17.7%) and pseudoarthrosis (9.3%) in fusion constructs using DBM. Studies using β-TCP reported a higher incidence of pseudoarthrosis (28.2%) and implant failures (17.9%).

CONCLUSIONS

Degenerative cervical conditions treated with one or two-level ACDF surgery using DBM, HA, or β-TCP with or without cervical plating are associated with complications such as adjacent segment disease, dysphagia, and pseudarthrosis. However, consequent to the study designs and clinical heterogeneity of the studies, it is not possible to correlate these complications accurately with any specific graft material employed. Further well-designed prospective studies are needed to correctly know the related morbidity of each graft used for achieving fusion in ACDF.

Comparing the Bridge-Type Zero-Profile Anchored Spacer (ROI-C) Interbody Fusion Cage System and Anterior Cervical Discectomy and Fusion (ACDF) with Plating and Cage System in Cervical Spondylotic Myelopathy

OBJECTIVE

To compare the clinical efficacy and radioactivity of the bridge-type zero-profile anchored spacer (ROI-C) interbody fusion cage and anterior cervical discectomy and fusion with plating and cage system (ACDF) for cervical spondylotic myelopathy (CSM).

METHODS

This is a retrospective contrastive study. We recruited 35 patients who received ROI-C (ROI-C group) and 34 patients who received ACDF (ACDF group), between January 2014 to January 2019, at our treatment center. The ROI-C group comprised of 11 males and 24 females with a mean age of 61.59 ± 8.21 years (range, 51-71 years). The ACDF group comprised of 12 males and 22 females with a mean age of 60.15 ± 7.52 years (range, 52-74 years). Neck Disability Index (NDI), Japanese Orthopaedic Association score (JOA), Odom's score, cervical Cobb angle, fusion rate, adjoining ossification, and dysphagia.

RESULTS

A total of 69 patients met the inclusion criteria, and these patients received more than two years of follow-up. There were significant differences in surgical duration (101 ± 22 min vs. 118 ± 29 min) and blood loss (102 ± 46 ml vs. 145 ± 58 ml) between two groups (P < 0.05). The JOA and NDI of these two groups of patients significantly improved, when compared with those before the operation (P < 0.05). Twenty-nine of 35 patients in the ROI-C group and 27 of 34 patients in ACDF group achieved good or excellent outcomes according to Odom's criteria. The cervical lordosis of both two groups significantly increased, when compared with those before the operation (P < 0.05). In the ROI-C group, the postoperative fusion rate was 85.7% at the 3-month follow-up and 100% at the final follow-up. In the ACDF group, the postoperative fusion rate was 82.4% at the 3-month follow-up and 100% at the final follow-up. The dysphagia incidence of the ACDF group was higher than that of the ROI-C group postoperatively and at the one month after surgery (P < 0.05), but no significant difference was found in the incidence of dysphagia at final follow-up (P > 0.05).

CONCLUSION

Both ROI-C and ACDF achieved good therapeutic effects. However, ROI-C can reduce the operation time and postoperative complications.

Anterior Cervical Discectomy and Fusion With a No-Profile Integrated Fixation Allograft Device: An In Vitro Biomechanical Analysis and Clinical Case Series

BACKGROUND

No-profile anterior cervical discectomy and fusion (ACDF) devices are commonplace in spinal surgery. Contained within the intervertebral margins, these devices diminish risks associated with anterior cervical plating, while also marginalizing cage migration and subsidence. However, these devices have been limited in their scope of implant material. Accordingly, a no-profile ACDF (npACDF) device supporting a machined allograft implant body with a connected load-sharing fixation interface was developed. However, it is not established in the literature whether the device supports early mechanical stability and subsequent boney fusion. The objective of this study was to assess this device in both the clinical and preclinical settings.

METHODS

Biomechanical Analysis: Twenty-four functional spinal units (FSUs) were divided into 4 groups (n = 6). Each group would receive a single construct: (1) npACDF device with connected polyetheretherketone (PEEK) body, (2) npACDF with connected allograft body, (3) npACDF (allograft body) with nonconnected fixation plate, and (4) standard ACDF plate and PEEK interbody cage. FSUs were subjected to pure moment loading (flexion/extension, lateral bending, and axial rotation) via a kinematic test machine in their intact state and then following instrumentation. Vertebral motion was recorded and range-of-motion (ROM) reduction, relative to intact, was calculated.Clinical Case Series: Ten patients receiving single-level ACDF with the npACDF allograft (connected) device for the treatment of persistent cervical radiculopathy or myelopathy were retrospectively reviewed at 12 months. Radiographic and patient reported outcomes were reported.

RESULTS

No differences in ROM existed between the npACDF constructs (P ≥ 0.99). Standard ACDF achieved more ROM reduction than the npACDF constructs in all directions (P ≥ 0.04). All subjects achieved fusion at 12 months.

CONCLUSIONS

The npACDF allograft device supported less motion reduction in comparison to traditional plating; however, case series data suggest the device provides clinically effective stability resulting in quality radiographic fusion and pain improvement.

CLINICAL RELEVANCE

This report provides both clinical and preclinical insight into a device which offers alternative design features to traditional continuous/rigid ACDF device designs.

LEVEL OF EVIDENCE: 4

Thorough Comparative Analysis of Stand-Alone Cage and Anterior Cervical Plate for Anterior Cervical Discectomy and Fusion in the Treatment of Cervical Degenerative Disease: A Systematic Review and Meta-Analysis

In this systematic review and meta-analysis, we aim to thoroughly describe and objectively compare the efficacy of anterior cervical plate (ACP) and stand-alone cage (SAC). Although recognized as an effective procedure for cervical degenerative disease (CDD), a debate between the methods of anterior cervical discectomy and fusion exists. ACP provides stability to the fusion construct; however, some complications have been reported, such as dysphagia, adjacent disc disease, and soft tissue injury. To overcome these complications, a SAC was later introduced. A systematic search was conducted on the basis of PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines to identify relevant studies through PubMed, Google Scholar, and Cochrane database. A total of 14 studies (960 patients) were included in the meta-analysis. Twenty outcomes were clinically and radiologically compared between the two procedures. ACP and SAC were comparable in terms of dysphasia rate, loss of segmental angle, loss of disc height, the Odom criteria, Robinson's criteria, hospital stay, Japanese Orthopaedic Association score, Neck Disability Index, Visual Analog Scale, and fusion time. However, SAC was superior in terms of shorter operation time, less blood loss, lower dysphagia rate, and lower rate of adjacent level disease, whereas ACP was advantageous in terms of lower subsidence rate, better maintenance of the cervical global and segmental angles and disc height, and higher fusion rate. Both procedures can be used in patients with CDD, although it might be more beneficial to choose ACP in patients with multi-level pathologies, wherein better mechanical stability is provided. However, SAC may be more beneficial to use in patients with comorbidities, anemia, or swelling problems because it offers lower complication rates.

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.

Does zero-profile anchored cage accompanied by a higher postoperative subsidence compared with cage-plate construct? A meta-analysis

Background

The zero-profile anchored cage (ZP) has been widely used for its lower occurrence of dysphagia. However, it is still controversial whether it has the same stability as the cage-plate construct (CP) and increases the incidence of postoperative subsidence. We compared the rate of subsidence after anterior cervical discectomy and fusion (ACDF) with ZP and CP to determine whether the zero-profile device had a higher subsidence rate.

Methods

We performed a meta-analysis of studies that compared the subsidence rates of ZP and CP. An extensive and systematic search covered the PubMed and Embase databases according to the PRISMA guidelines and identified ten articles that satisfied our inclusion criteria. Relevant clinical and radiological data were extracted and analyzed by the RevMan 5.3 software.

Results

Ten trials involving 626 patients were included in this meta-analysis. The incidence of postoperative subsidence in the ZP group was significantly higher than that in the CP group [15.1% (89/588) versus 8.8% (51/581), OR = 1.97 (1.34, 2.89), P = 0.0005]. In the subgroup analysis, we found that the definition of subsidence did not affect the higher subsidence rate in the ZP group. Considering the quantity of operative segments, there was no significant difference in the incidence of subsidence between the two groups after single-level fusion (OR 1.43, 95% CI 0.61–3.37, P = 0.41). However, the subsidence rate of the ZP group was significantly higher than that of the CP group (OR 2.61, 95% CI 1.55–4.40, P = 0.0003) after multilevel (≥ 2-level) procedures. There were no significant differences in intraoperative blood loss, JOA score, NDI score, fusion rate, or cervical alignment in the final follow-up between the two groups. In addition, the CP group had a longer operation time and a higher incidence of dysphagia than the ZP group at each follow-up time.

Conclusion

Based on the limited evidence, we suggest that ZP has a higher risk of postoperative subsidence than CP, although with elevated swallowing discomfort. A high-quality, multicenter randomized controlled trial is required to validate our results in the future.

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.

Change in sagittal profile after implantation of anchored interbody cage in the surgical procedure for degenerative cervical spine disease

BACKGROUND

The aim of this study was to verify the relationship between changes in the segmental sagittal profile (SSP) and changes in the global sagittal profile (GSP) after anterior cervical discectomy with anchored cage implantation (ACDF).

STUDY DESIGN

Prospective study with 2-year follow-up.

METHODS

This study includes 104 patients after 1-level or 2-level ACDF operated between the May 2013 and March 2016. SSP was evaluated by Cobb angle measurement of operated motion segment (CobbS) and GSP was evaluated by Cobb angle measurement in C2-C7 segments (CobbG). Both SSP and GSP were measured pre- and postoperatively within a 24 months follow-up period. The influence of factors such as age, gender, number of treated segments and osteoporosis was evaluated using t-tests. The correlation between SSP and GSP changes was assessed by Pearson's correlation coefficient.

RESULTS

In the early postoperative period after 1-level ACDF, there was a significantly greater increase in CobbS compared to that of the 2-level ACDF (P=0.0149). Male patients experienced a significant decrease of CobbG during the first 6 months after surgery as well as patients with osteoporosis within 12 months after ACDF. After ACDF the SSP change weakly correlated with the GSP change.

CONCLUSION

SSP change after 1- or 2-level ACDF correlates mostly weakly with GSP change. Male gender and osteoporosis were identified as risk factors for global lordotisation following ACDF.

Eleven-Year Follow-Up of Two Cohorts of Patients Comparing Stand-Alone Porous Tantalum Cage Versus Autologous Bone Graft and Plating in Anterior Cervical Fusions

BACKGROUND

Anterior cervical discectomy and fusion with a porous tantalum cage is an accepted method to treat degenerated cervical discs, with good results, similar to those with autologous bone graft and plating at short- and mid-term follow-up. However, to date, long-term follow-up studies have been performed.

METHODS

We performed a retrospective, single-center study to evaluate the outcomes of 2 cohorts from a previous prospective randomized controlled trial comparing stand-alone tantalum cage (group 1, 27 patients) with autologous bone graft and plating (group 2, 30 patients) for single-level anterior cervical discectomy and fusion at 11 years of follow-up. The usual clinical and radiological outcomes and "overall success," proposed by the Food and Drug Administration, were evaluated.

RESULTS

The improvement in clinical outcomes achieved postoperatively was maintained similarly in the 2 cohorts at 11 years of follow-up. In group 1, the cage had subsided 2-3 mm in 12 patients (44%), segmental lordosis was maintained in 16 patients (59%), adjacent segment degeneration had developed or progressed in 27 of the adjacent segments (50%) in 15 patients (56%), and postoperative nonprogressive deformation of the anterior aspect of the cage was observed in 7 (26%) and minor fragmentation in 3 (11%) patients. In group 2, segmental lordosis was maintained in 90% of the patients and adjacent segment degeneration had developed or progressed in 15 patients (50%).

CONCLUSIONS

These results show that the clinical and radiological outcomes achieved at mid-term follow-up using a tantalum cage for single-level anterior cervical discectomy and fusion will be maintained for 11 years postoperatively, similar to the results with autologous bone graft and plating.

Curative effect of posterior lumbar interbody fusion in the treatment of single-segment lumbar degenerative disease and changes in adjacent segment quantitative score

Curative effect of posterior lumbar interbody fusion (PLIF) in the treatment of single-segment lumbar degenerative disease and changes in adjacent segment quantitative score was investigated. A total of 86 patients with single-segment lumbar degenerative disease were randomly selected and divided into control group (n=43) and observation group (n=43). The control group was treated with posterolateral lumbar fusion, while the observation group was treated with PLIF. The observation group had a significantly longer operation time and shorter hospitalization time compared with the control group (P<0.05). The excellent-good rate of treatment in the observation group (90.69%) was obviously higher than that in the control group (62.79%) (P<0.05). The levels of creatine phosphokinase in the two groups were significantly increased at 1, 3 and 5 days after operation (P<0.05), and reached the peak at 1 day after operation and returned to normal basically at 7 days after operation. Oswestry disability index in the observation group at 1, 6 and 12 months after operation were significantly lower than those in the control group (P<0.05). There was no significant difference in the MRI-T2 relaxation time of multifidus muscle at 3 months after operation between the two groups (P>0.05). The grade I and II interbody fusion rates in the observation group at 12 months after operation were significantly higher than those in the control group (P<0.05). The mean spinal canal areas and adjacent segment quantitative scores in the two groups after operation were significantly improved compared with those before operation, and they were improved more obviously in the observation group than those in the control group (P<0.05). PLIF has a more definite short-term curative effect and a higher interbody fusion rate in the treatment of single-segment lumbar degenerative disease, which is more conducive to promoting the postoperative rehabilitation of patients and slowing down the occurrence of adjacent segment degeneration.

Effectiveness of dynamic fixation Coflex treatment for degenerative lumbar spinal stenosis

The aim of the present study was to examine the curative effect of dynamic fixation Coflex treatment for patients with degenerative lumbar spinal stenosis. In the present study, 78 patients with degenerative lumbar spinal stenosis were recruited and divided equally into the control and observation groups. The control group was treated with traditional decompression fusion and the observation group received dynamic fixation Coflex system. Surgery and hospitalization were shorter in the observation group than in the control group. Intraoperative blood loss and drainage volume after surgery were significantly lower in the observation group compared to the control group. The treatment effective rate for the observation group was significantly higher. Visual analogue scale, Oswestry disability index and Japanese Orthopaedic Association pain and functional scores as well as postoperative vertebral canal area and adjacent segment quantitative scores improved after surgery in the two groups, but the observation group showed greater improvement. The curative effect of dynamic fixation Coflex treatment for degenerative lumbar spinal stenosis demonstrates advantages over traditional surgery, including less trauma and bleeding, pain reduction, improved postoperative rehabilitation, and lower incidence of adjacent segment degeneration.

Can an Anchored Cage be Substituted for an Anterior Cervical Plate and Screw for Single-Level Anterior Cervical Fusion Surgery?: Prediction of Poor Candidates Through a Review of Early Clinical and Radiologic Outcomes

STUDY DESIGN

This is a case series of device failure patients.

OBJECTIVE

To identify poor candidates for anterior cervical discectomy and fusion (ACDF) using an anchored cage.

SUMMARY OF BACKGROUND DATA

An anchored cage has been used as an alternative implant for ACDF surgery because of ease of use, relatively acceptable fusion rate, and lower risk of plate-related complications, including dysphagia.

MATERIALS AND METHODS

We retrospectively reviewed the outcomes of 36 patients who underwent ACDF using an anchored cage between January 2012 and December 2013. The initial diagnoses included 8 traumatic soft disk herniations without posterior ligamentous complex injury, 25 degenerative soft disk herniations, 1 degenerative foraminal stenosis, 1 traumatic soft disk herniation after reducing a unilaterally dislocated facet joint, and 1 subluxation of a previously implanted cervical artificial disk. We encountered 5 cases with poor outcomes and performed 3 revisions on the index level. We reviewed the clinical and radiologic data for 31 patients with reasonable outcomes and reviewed the failed 5 cases separately.

RESULTS

Among the 31 patients with reasonable outcomes, all the clinical parameters improved. For the radiologic outcomes, 10 cases of cage subsidence occurred and no patient experienced instability.Among the 5 patients with poor outcomes, 1 patient had traumatic soft disk herniation and a reduced unilaterally dislocated facet joint, 1 patient had subluxation of a previously implanted cervical artificial disk, and 3 patients had degenerative soft disk herniation and poor bone quality. Although 3 patients required revision surgeries, 2 patients showed only radiologic failures without revision.

CONCLUSIONS

We analyzed the short-term outcomes of ACDF using an anchored cage and observed 5 patients with poor outcomes among 36 patients. We recommend the use of a single anchored cage for patients with definite evidence of posterior column stability and healthy bone.

LEVEL OF EVIDENCE

Level 3.

Single anterior cervical discectomy and fusion (ACDF) using self- locking stand-alone polyetheretherketone (PEEK) cage: evaluation of pain and health-related quality of life

BACKGROUND

Anterior cervical discectomy and fusion (ACDF) constitutes the conventional treatment of cervical disc herniation due to degenerative disc disease (DDD). ACDF with plating presents a variety of complications postoperatively and stand-alone cages are thought to be a promising alternative. The aim of this study was firstly, to analyze prospectively collected data from a sample of patients treated with single ACDF using C-Plus self-locking stand-alone PEEK cage system, without the use of plates or screws, in order to evaluate pain levels of patients, utilizing Neck and Arm Pain scale as an expression of visual analogue scale (VAS). Secondly, we aimed to evaluate health-related quality of life, via the short-form 36 (SF-36) and Neck Disability Index (NDI).

METHODS

Thirty-six patients (19 male and 17 female) with mean age 49.6±7 years old who underwent successful single ACDF using self-locking stand-alone PEEK cage for symptomatic cervical DDD were selected for the study. Neck and Arm pain, as well as SF-36 and NDI were estimated preoperatively and 1, 3, 6, and 12 months postoperatively. Patients underwent preoperative and postoperative clinical, neurological and radiological evaluation.

RESULTS

The clinical and radiological outcomes were satisfactory after a minimum 1-year follow-up. All results were statistically important (P<0.05), excluding improvement in NDI measured between 6 and 12 months. SF-36, Neck Pain, as well as Arm Pain featured gradual and constant improvement during follow-up, with best scores presenting at 12 months after surgery, while NDI reached its best at 6 months postoperatively.

CONCLUSIONS

Generally, all scores showed improvement postoperatively during the different phases of the follow-up. Subsequently, ACDF using C-Plus cervical cage constitutes an effective method for cervical disc herniation treatment, in terms of postoperative improvement on pain levels and health-related quality of life and a safe alternative to the conventional method of treatment for cervical DDD.

Cervical Burst Fracture in a Patient with Contiguous 2-Level Cervical Stand-Alone Cages

BACKGROUND

Cervical stand-alone interbody cages have seen increasingly wider use over the plate-and-screw construct in single-level anterior cervical discectomy and fusion (ACDF) in the treatment of cervical disc herniation and degenerative spondylotic conditions. Despite positive clinical outcomes, the efficacy and safety of using these devices in contiguous multilevel ACDF has remained controversial. This report discusses a burst fracture seen as a complication in multilevel cervical stand-alone cage use.

CASE DESCRIPTION

A 39-year-old woman with a history of C5-C6 and C6-C7 ACDF with contiguous stand-alone interbody cages 2 years prior, presented with recurrent arm and neck pain with myelopathy. Computed tomography scan revealed a burst fracture of the C6 vertebral body with retropulsion of fragments compressing the spinal cord.

CONCLUSIONS

This case suggests that use of cervical stand-alone cages in contiguous levels may cause late complications despite good instrumentation and illustrates the need for more careful consideration of technique selection in multilevel ACDF.

Comparison of Radiologic Outcomes of Different Methods in Single-Level Anterior Cervical Discectomy and Fusion

Objective

Anterior cervical discectomy and fusion (ACDF) is a choice of surgical procedure for cervical degenerative diseases associated with radiculopathy or myelopathy. However, the patients undergoing ACDF still have problems. The purpose of the present study is to evaluate the radiologic results of 3 different methods in single-level ACDF.

Methods

We conducted a retrospective collection of radiological data from January 2011 to December 2014. A total of 67 patients were included in this study. The patients were divided into 3 groups by operation procedure: using stand-alone cage (group cage, n=20); polyether-ether-ketone (PEEK)-titanium combined anchored cage (group AC, n=21); and anterior cervical cage-plate (group CP, n=26). Global cervical lordosis (C2-C7 Cobb angle), fused segment height, fusion rate, and cervical range of motion (ROM) were measured and analyzed at serial preoperative, postoperative, 6-month, and final 1-year follow-up.

Results

Successful bone fusion was achieved in all patients at the final follow-up examination; however, the loss of disc height over 3 mm at the surgical level was observed in 6 patients in group cage. Groups AC and CP yielded significantly better outcomes than group cage in fused segment height and cervical ROM(p=0.01 and p=0.02, respectively). Furthermore, group AC had similar radiologic outcomes to those of group CP.

Conclusion

The PEEK-titanium combined anchored cage may be a good alternative procedure in terms of reducing complications induced by plate after ACDF.

Surgical Outcomes of Anterior Cervical Fusion Using Deminaralized Bone Matrix as Stand-Alone Graft Material: Single Arm, Pilot Study

Objective

To investigate the safety and efficacy of demineralized bone matrix (DBM) as a bone graft substitute for anterior cervical discectomy and fusion (ACDF) surgery.

Methods

Twenty consecutive patients treated with ACDF using stand-alone polyestheretherketone (PEEK) cages (Zero-P) with DBM(CGDBM100) were prospectively evaluated with a minimum of 6 months of follow-up. Radiologic efficacy was evaluated with a 6-point scoring method for osseous fusion using plain radiograph and computed tomogrpahy scans. Clinical efficacy was evaluated using the visual analogue scale (VAS), Owestry disability index (ODI), and short-form health questionnaire-36. The safety of the bone graft substitute was assessed with vital sign monitoring and a survey measuring complications at each follow-up visit.

Results

There were significant improvements in VAS and ODI scores at a mean 6-month follow-up. Six months after surgery, solid fusion was achieved in all patients. Mean score on the 6-point scoring system was 5.1, and bony formation was found to score at least 4 points in all patients. There was no case with implant-related complications such as cage failure or migration, and no complications associated with the use of CGDBM100.

Conclusion

ACDF using CGDBM100 demonstrated good clinical and radiologic outcomes. The fusion rate was comparable with the published results of traditional ACDF. Therefore, the results of this study suggest that the use of a PEEK cage packed with DBM for ACDF is a safe and effective alternative to the gold standard of autologous iliac bone graft.

Outcomes Evaluation of Zero-Profile Devices Compared to Stand-Alone PEEK Cages for the Treatment of Three- and Four-Level Cervical Disc Disease

Background: Anterior cervical discectomy and fusion (ACDF) is a well-accepted treatment option for patients with cervical spine disease. Three- and four-level discectomies are known to be associated with a higher complication rate and lower fusion rate than single-level surgery. This study was performed to evaluate and compare zero-profile fixation and stand-alone PEEK cages for three- and four-level ACDF.

Methods: Two cohorts of patients who underwent ACDF for the treatment of three- and four-level disease were compared. Thirty-three patients underwent implantation of zero-profile devices that included titanium screw fixation (Group A). Thirty-five patients underwent implantation of stand-alone PEEK cages without any form of screw fixation (Group B).

Results: In Group A, twenty-seven patients underwent a three-level and six patients a four-level ACDF, with a total of 105 levels. In Group B, thirty patients underwent a three-level and five patients underwent a four-level ACDF, with a total number of 110 levels. In Group A, the mean preoperative visual analog scale score (VAS) for arm pain was 6.4 (range 3-8), and the mean postoperative VAS for arm pain decreased to 2.5 (range 1-7). In group B, the mean preoperative VAS of arm pain was 7.1 (range 3-10), and the mean postoperative VAS of arm pain decreased to 2 (range 0-4). In Group A, four patients (12%) developed dysphagia, and in Group B, three patients (9%) developed dysphagia. 

Conclusions: This study found zero-profile instrumentation and PEEK cages to be both safe and effective for patients who underwent three- and four-level ACDF, comparable to reported series using plate devices. Rates of dysphagia for the cohort were much lower than reports using plate devices. Zero-profile segmental fixation devices and PEEK cages may be considered as viable alternatives over plate fixation for patients requiring multi-level anterior cervical fusion surgery.

Stand-Alone Cages for Anterior Cervical Fusion: Are There No Problems?

Objective

There are complications in stand-alone cage assisted anterior cervical discectomy and fusion (ACDF), such as cage subsidence and kyphosis. Here we report our clinical result on ACDF, comparing with stand-alone cages and with cervical plate system for degenerative cervical spine diseases.

Methods

Patients with degenerative cervical disease who were diagnosed and treated in Konyang University Hospital between January 2004 and December 2014 were included in this study. Patients who had operation in single level ACDF were selected. Patients scored the degree of pain using visual analog scale before and after the surgery. Subsidence was defined as ≥3-mm decrease of the segmental height, and cervical kyphosis was defined as progression of ≥5° at 12 months after postoperative follow-up compared to that measured at the immediate postoperative period.

Results

A total of 81 patients were enrolled for this study. Forty-five patients were included in a cervical plate group and the others were in stand-alone cage group. There was no statistical difference in pain score between the 2 groups. Segmental subsidence was observed in 7 patients (15.6%) in plate-assisted cervical fusion group, and 13 patients (36.1%) in stand-alone cage group. Segmental kyphosis was observed in 4 patients (8.9%) in plate-assisted cervical fusion group, and 10 patients (27.8%) in stand-alone cage group. There was statistical difference between the 2 groups.

Conclusion

There was no difference in pain between 2 groups. But stand-alone case group showed higher incidence rate than plate-assisted cervical fusion group in segmental subsidence and cervical kyphosis. When designing cervical fusion, more attention should be given selecting the surgical technique.

A Meta-Analysis of the Incidence of Patient-Reported Dysphagia After Anterior Cervical Decompression and Fusion with the Zero-Profile Implant System

Dysphagia is a well-known complication following anterior cervical surgery. It has been reported that the Zero-profile Implant System can decrease the incidence of dysphagia following surgery, however, dysphagia after anterior cervical decompression and fusion (ACDF) with the Zero-profile Implant System remains controversial. Previous studies only focus on small sample sizes. The objective of this study was to determine the incidence of dysphagia after ACDF with the Zero-profile Implant System. Studies were collected from PubMed, EMBASE, the Cochrane library and the China Knowledge Resource Integrated Database using the keywords "Zero-profile OR Zero-p) AND (dysphagia OR [swallowing dysfunction]". The software STATA (Version 13.0) was used for statistical analysis. Statistical heterogeneity across the various trials, a test of publication bias and sensitivity analysis was performed. 30 studies with a total of 1062 patients were included in this meta-analysis. The occurrence of post-operative transient dysphagia ranged from 0 to 76 % whilst the pooled incidence was 15.6 % (95 % CI, 12.6, 18.5 %). 23 studies reported no persistent dysphagia whilst seven studies reported persistent dysphagia ranging from 1 to 7 %). In summary, the present study observed a low incidence of both transient and persistent dysphagia after ACDF using the Zero-profile Implant System. Most of the dysphagia was mild and gradually decreased during the following months. Moderate or severe dysphagia was uncommon. Future randomized controlled multi-center studies and those focusing on the mechanisms of dysphagia and methods to reduce its incidence are required.

An Incidental Finding of a Radiopaque Pill following Cervical Spinal Surgery in a Parkinson's Disease Patient

There are previous reports of the identification of radiopaque medications on abdominal X-rays or computed tomography (CT). We describe an interesting case of the incidental identification of a radiopaque medication on cervical spinal CT following cervical spinal surgery. A sixty seven-year-old male patient with Parkinson's disease (PD) visited our emergency center with a C5-6 dislocation and fracture. Surgery was performed with open reduction and pedicle screw fixation through the posterior approach. No abnormal events occurred during the perioperative period. However, a radiopaque incidental foreign body in front of the C6 vertebrae was found on a cervical spinal CT and X-rays that were performed as routine examinations on postoperative day 3. After 6 hours, we performed gastrofibroscopy (GFS) but were unable to find anything. Therefore, we checked all of his medications related to the neck and check X-ray again. One enteric-coated pill he had taken exhibited strong radiodensity. Although our patient underwent an unnecessary GFS, every spinal surgeon should keep in mind that radiopaque pills can appear similar to spinal instruments on X-ray and CT. In addition, we should also know the associated dysphagia is a possible cause of the delayed passage of medicine in PD with or without cervical osteophytes.

Cervical Stand-Alone Polyetheretherketone Cage versus Zero-Profile Anchored Spacer in Single-Level Anterior Cervical Discectomy and Fusion : Minimum 2-Year Assessment of Radiographic and Clinical Outcome

Objective

We compared the clinical and radiographic outcomes of stand-alone polyetheretherketone (PEEK) cage and Zero-Profile anchored spacer (Zero-P) for single level anterior cervical discectomy and fusion (ACDF).

Methods

We retrospectively reviewed 121 patients who underwent single level ACDF within 2 years (Jan 2011-Jan 2013) in a single institute. Total 50 patients were included for the analysis who were evaluated more than 2-year follow-up. Twenty-nine patients were allocated to the cage group (m : f=19 : 10) and 21 for Zero-P group (m : f=12 : 9). Clinical (neck disability index, visual analogue scale arm and neck) and radiographic (Cobb angle-segmental and global cervical, disc height, vertebral height) assessments were followed at pre-operative, immediate post-operative, post-3, 6, 12, and 24 month periods.

Results

Demographic features and the clinical outcome showed no difference between two groups. The change between final follow-up (24 months) and immediate post-op of Cobb-segmental angle (p=0.027), disc height (p=0.002), vertebral body height (p=0.033) showed statistically better outcome for the Zero-P group than the cage group, respectively.

Conclusion

The Zero-Profile anchored spacer has some advantage after cage for maintaining segmental lordosis and lowering subsidence rate after single level anterior cervical discectomy and fusion.

Clinical comparison of Zero-profile interbody fusion device and anterior cervical plate interbody fusion in treating cervical spondylosis

OBJECTIVE

the aim of the study was to compare the clinical effect of Zero-profile interbody fusion device (Zero-P) with anterior cervical plate interbody fusion system (PCB) in treating cervical spondylosis.

METHODS

a total of 98 patients with cervical spondylosis (110 segments) in February 2011 to January 2013 were included in our hospital. All participants were randomly divided into observation group and control group with 49 cases in each group. The observation group was treated with Zero-P, while the control group received PCB treatment. Comparison of the two groups in neurological function score (JOA), pain visual analogue scale (VAS), the neck disability index (NDI), quality of life score (SF-36) and cervical curvature (Cobb angle) change were recorded and analyzed before and after treatment.

RESULTS

The observation group was found with 90% excellent and good rate, which was higher than that of the control group (80%). Dysphagia rate in observational group was 16.33% (8/49), which was significantly less than that in control group (46.94%). Operation time and bleeding volume in the observation group was less than those in control group. Postoperative improvements of JOA score, VAS score, and NDI in observational group were also significantly better than that in control group (P<0.05).

CONCLUSION

The clinical effect of Zero-P and PCB for the treatment of cervical spondylosis was quite fair, but Zero-P showed a better therapeutic effect with improvement of life quality.

Early Radiographic and Clinical Outcomes Study Evaluating an Integrated Screw and Interbody Spacer for One- and Two-Level ACDF

BACKGROUND

Multiple techniques and implants can be used in ACDF, the newest of which are integrated cage and screw constructs. These devices may be beneficial over anterior plate constructs due to a negligible anterior profile that may reduce dysphagia. The goal of this study is to review the early radiographical and clinical results associated with a low profile integrated intervertebral cage in one- and two-level anterior column fusions.

METHODS

Fusion rates, incidence of hardware failure and deformity correction were assessed through 1 year. Patientreported scores, including VAS for neck pain, and improvements in axial neck pain and neurologic deficit from the preoperative baseline were quantified at 3, 6 and 12 months post-operatively. The incidence of dysphagia was recorded.

RESULTS

Lordosis and disc space height at the operated levels increased an average of 4.5° and 3.3mm after device placement (p<0.001). Sagittal plane correction was maintained at 1 year. VAS improved from an average of 5.1 preoperatively to 3.1 immediately postoperatively and was maintained at 12 months. At 3 months, patient-reported improvements in axial neck pain and neurologic deficit were 85% and 93%, respectively. Reported improvements were sustained for both parameters at 12 months (77% and 86%, respectively). Fusion was noted in 93% of the operated levels. There were two documented cases of dysphagia that lasted more than 5 weeks, both following two level ACDFs with the test device (3.5% rate of chronic dysphagia).

CONCLUSIONS

The low profile integrated device improved lordosis at the operated level that was maintained at 1 year. Fusion rates with the new device are consistent with ACDF using anterior plating. In combination with improvements in pain and a minimal rate of dysphagia, study findings support the use of integrated interbody spacers for use in one- and two-level ACDF procedures.

LEVEL OF EVIDENCE

Level IV, Case Series.

Meta-Analysis Comparing Zero-Profile Spacer and Anterior Plate in Anterior Cervical Fusion

Background

Anterior plate fusion is an effective procedure for the treatment of cervical spinal diseases but is accompanied by a high incidence of postoperative dysphagia. A zero profile (Zero-P) spacer is increasingly being used to reduce postoperative dysphagia and other potential complications associated with surgical intervention. Studies comparing the Zero-P spacer and anterior plate have reported conflicting results.

Methodology

A meta-analysis was conducted to compare the safety, efficacy, radiological outcomes and complications associated with the use of a Zero-P spacer versus an anterior plate in anterior cervical spine fusion for the treatment of cervical spinal disease. We comprehensively searched PubMed, Embase, the Cochrane Library and other databases and performed a meta-analysis of all randomized controlled trials (RCTs) and prospective or retrospective comparative studies assessing the two techniques.

Results

Ten studies enrolling 719 cervical spondylosis patients were included. The pooled data showed significant differences in the operation time [SMD = –0.58 (95% CI = −0.77 to 0.40, p < 0.01)] and blood loss [SMD = −0.40, 95% CI (−0.59 to –0.21), p < 0.01] between the two groups. Compared to the anterior plate group, the Zero-P group exhibited a significantly improved JOA score and reduced NDI and VAS. However, anterior plate fusion had greater postoperative segmental and cervical Cobb’s angles than the Zero-P group at the last follow-up. The fusion rate in the two groups was similar. More importantly, the Zero-P group had a lower incidence of earlier and later postoperative dysphagia.

Conclusions

Compared to anterior plate fusion, Zero-P is a safer and effective procedure, with a similar fusion rate and lower incidence of earlier and later postoperative dysphagia. However, the results of this meta-analysis should be accepted with caution due to the limitations of the study. Further evaluation and large-sample RCTs are required to confirm and update the results of this study.

The VariLift(®) Interbody Fusion System: expandable, standalone interbody fusion

Intervertebral fusion cages have been in clinical use since the 1990s. Cages offer the benefits of bone graft containment, restored intervertebral and foraminal height, and a more repeatable, stable procedure compared to interbody fusion with graft material alone. Due to concerns regarding postoperative stability, loss of lordosis, and subsidence or migration of the implant, interbody cages are commonly used with supplemental fixation such as pedicle screw systems or anterior plates. While providing additional stability, supplemental fixation techniques increase operative time, exposure, cost, and morbidity. The VariLift(®) Interbody Fusion System (VariLift(®) system) has been developed as a standalone solution to provide the benefits of intervertebral fusion cages without the requirement of supplemental fixation. The VariLift(®) system, FDA-cleared for standalone use in both the cervical and lumbar spine, is implanted in a minimal profile and then expanded in situ to provide segmental stability, restored lordosis, and a large graft chamber. Preclinical testing and analyses have found that the VariLift(®) System is durable, and reduces stresses that may contribute to subsidence and migration of other standalone interbody cages. Fifteen years of clinical development with the VariLift(®) system have demonstrated positive clinical outcomes, continued patient maintenance of segmental stability and lordosis, and no evidence of implant migration. The purpose of this report is to describe the VariLift(®) system, including implant characteristics, principles of operation, indications for use, patient selection criteria, surgical technique, postoperative care, preclinical testing, and clinical experience. The VariLift(®) System represents an improved surgical option for a stable interbody fusion without requiring supplemental fixation.