Stand-alone Cervical Cages Research Articles

Outcomes of stand-alone cervical cage versus cervical cage with plate in single or double level anterior cervical discectomy and fusion: Comparative Study

Outcomes of stand-alone cervical cage versus cervical cage with plate in single or double level anterior cervical discectomy and fusion: Comparative Study

Clinical and Radiological Outcome in a Series of Patients Treated by Anterior Cervical Discectomy and Fusion: Retrospective Controlled Study With 2 Different Stand-Alone Cages.

Cervical spine balance and alignment targets after cervical spine surgery are poorly established in patients with cervical spine degenerative disease surgically treated by anterior cervical discectomy and fusion (ACDF). The objective of the study is to determine the correlation between radiological and clinical outcomes in patients surgically treated by ACDF with 2 different stand-alone cervical cages. Clinical outcomes were evaluated using visual analog scale (VAS), Neck Disability Index (NDI), Nurick Scale, and Japanese Orthopedic Association score for myelopathy. Radiological evaluation included cervical and segmental Cobb angles, cervical sagittal vertical axis (cSVA), T1 slope (T1s), C0-C2 angle, fusion rates, adjacent segment degeneration, and cage subsidence. A total of 80 patients were included with an average age of 53 years. There was a statistically significant improvement in both clinical and radiological evaluations. There was a statistical significant correlation between cervical pain on cervical VAS and cSVA. There was a significant correlation between postoperative T1s and cSVA, related to the improvement in cervical angles. There was no significant difference in rates of fusion, adjacent segment changes, or reoperation between both cervical cages, and there was a higher rate of subsidence in the Aleutian group. There were significant differences between both groups on postoperative NDI and VAS, but this difference is not maintained during follow-up. Cervical sagittal balance is directly related to clinical outcome in patients with cervical spine degenerative disease. Both cervical implants analyzed were comparable in clinical and radiological outcomes. There are important clinical and radiological parameters that should be taken into account for the analysis of the surgical outcome of patients treated by ACDF; this is one of the few studies that report the results with 2 different cervical cage designs.

Comparative study of anterior cervical discectomy and fusion by anterior cervical plate and stand-alone cervical cage

<p class="abstract"><strong>Background:</strong> Anterior cervical discectomy (ACD) was used for management of degenerative cervical disc disorders (DCDD) in previous days. Further research and developments in management of DCDD led to evolution of standard and widely used operative technique as anterior cervical discectomy and fusion (ACDF) by either anterior cervical plate (ACDF-ACP) with bone grafting or stand-alone cage (ACDF-SAC). There is less data available in literature regarding when and where to use ACDF-ACP and ACDF-SAC.</p><p class="abstract"><strong>Methods:</strong> The study was conducted on 20 patients operated in Government Medical College and Hospital and Pacific Hospital and Research Centre, Aurangabad from June 2018 to March 2020. These patients divided into group A - 10 patients, operated by ACDF-SAC which are further divided as group Aa - 6 patients - operated for single level ACDF-SAC and group Ab - 4 patients - operated for two level ACDF-SAC, group B - 10 patients, operated by ACDF-ACP which are further divided as group Ba - 5 patients - operated for single level ACDF-ACP and group Bb - 5 patients - operated for two level ACDF-ACP. Patients evaluated preoperatively and postoperatively using X-ray cervical spine anteroposterior (AP) and lateral views, MRI cervical spine, visual analogue scale (VAS) for pain, Robinson’s criteria and Cobb’s angle.<strong></strong></p><p class="abstract"><strong>Results:</strong> In our study we found, ACDF-SAC has small incision size, less intraoperative time, easy to carry out for surgeons, less intraoperative complications and better clinical outcome as compared to ACDF-ACP. Whereas only radiological results were better in ACDF-ACP than ACDF-SAC.</p><p class="abstract"><strong>Conclusions:</strong> ACDF-SAC is superior to ACDF-ACP for appropriately selected patients and in well experienced hands.</p>

STAND-ALONE CERVICAL CAGE FOR CERVICAL RADICULOPATHY: A RETROSPECTIVE STUDY

Introduction: Cervical radiculopathy is a clinical condition characterized by unilateral arm pain, numbness and tingling in a dermatomal distribution in the hand, and weakness in specific muscle groups that can be treated with nonsurgical or surgical method. This study aims to evaluate the outcome of the stand-alone cervical cage surgical method for cervical radiculopathy in our hospital institution from 2013 to 2017Methods: This is a retrospective observational study on every patient who undergoes a stand-alone cervical cage for cervical radiculopathy in our hospital institution from 2013 to 2017. The study runs from December 2017 until April 2018. We evaluated the clinical outcome with the Neck Disability Index (NDI). The data were collected from medical records, and postoperative follow up is done by house visits, phone calls, and outpatient visits.Results: Five male and one female subjects with a mean age of 58 years old (45–65 years old) underwent the procedure; one patient passed away on three year postoperative due to other events not related to operation procedure; one patient could no longer be reached. Four patient has an increasing score of NDI postoperative. There is no postoperative complicationConclusion: Stand-alone cervical cage is an excellent treatment for cervical radiculopathy in our hospital institution from 2013 to 2017.

Locking Stand-Alone Cage Constructs for the Treatment of Cervical Spine Degenerative Disease.

Study DesignProspective case series study.PurposeDescription of the outcome of stand-alone cervical cages for single and multilevel cervical degenerative spine disease.Overview of LiteratureThe aim of anterior cervical discectomy and fusion (ACDF) for cervical spine disease is to improve patient symptoms and spine stability and restore lordosis. Locking stand-alone cages were developed with the goal of minimizing soft tissue disruption anterior to the vertebrae and reducing the profile of the construct by avoiding an anterior plate, thereby maximizing ACDF benefits.MethodsThis study comprises a case series of patients surgically treated between July 2015 and February 2018 who received single or multilevel ACDF with a zero-profile stand-alone cervical cage. Surgical and clinical preoperative evaluation and surgical outcomes were evaluated using pre- and postoperative Nurick, Visual Analog Scale (VAS), Neck Disability Index (NDI), Japanese Orthopedic Association (JOA) score for myelopathy scales, cervical Cobb angles, postoperative surgical complications, and fusion and subsidence rates.ResultsFifty-three patients underwent ACDF; the mean age of these patients was 58.8 years, and their preoperative VAS, NDI, and JOA scores were 8.1, 31.6, and 15.3, respectively. The preoperative Cobb angle was 30.7°. Forty-five percent of patients had one-level, 54.7% had two-level, and 13.2% had three-level procedures. On preoperative magnetic resonance imaging, foraminal stenosis was present in 94.3% of patients, whereas medullar stenosis was present in 41.5%. The rate of complications was 5.7%: two patients had postoperative dysphagia (3.7%), and one patient had a surgical site hematoma. Mean postoperative follow-up time was 6.7 months; postoperative VAS, NDI, and JOA scores were 2.4, 15.9, and 15.8, respectively. Postoperative Cobb angle was 35.9°, fusion rate was 84.9%, and subsidence rate was 11.3%.ConclusionsACDF with zero-profile stand-alone cervical devices is an excellent option for cervical degenerative disc disease of one, two, and three levels, with similar results reported when using ACDF with either cage or plate.

Stand-Alone Cervical Cages in 2-Level Anterior Interbody Fusion in Cervical Spondylotic Myelopathy: Results from a Minimum 2-Year Follow-up.

Study DesignA retrospective review of patients who underwent 2-level anterior cervical discectomy and fusion (ACDF) with standalone polyetheretherketone (PEEK) cages for cervical spondylotic myelopathy (CSM).Purpose To evaluate the efficacy of stand-alone PEEK cage in 2-level cervical interbody fusion for CSM.Overview of LiteratureACDF is a standard surgical procedure to treat degenerative disc disease. However, the use of additional anterior plating for 2-level ACDF remains controversial.MethodsWe reviewed outcomes of patients who underwent 2-level ACDF with stand-alone PEEK cages for CSM over a 7-year period (2007–2015) in a regional hospital. Japanese Orthopaedic Association (JOA) score, fusion rate, subsidence rate, cage migration, and cervical alignment by the C2–7 angle as well as the local segmental angle (LSA) of the cervical spine were assessed.ResultsIn total, 31 patients (mean age, 59 years; range, 36–87 years) underwent 2-level ACDF with a cage-only construct procedure between 2007 and 2015. The minimum follow-up was 24 months; mean follow-up was 51 months. C3–5 fusion was performed in 45%, C4–6 fusion in 32%, and C5–7 fusion in 23%. Mean JOA score improved from 10.1±2.2 to 13.9±2.1 (p<0.01) at the 24-month follow-up. Fusion was achieved in all patients. Subsidence occurred in 22.5% of the cages but was not associated with differences in JOA scores, age, sex, or levels fused. Lordosis of the C2–7 angle and LSA increased after surgery, which were maintained for up to 1 year but subsequently disappeared after 2 years, yet the difference was not statistically significant. No cage migration was noted; two patients developed adjacent segment disease requiring posterior laminoplasty 3 years after ACDF.ConclusionsThe use of a stand-alone PEEK cage in a 2-level cervical interbody fusion achieves satisfactory improvements in both clinical outcomes and fusion.

Failure Patterns in Standalone Anterior Cervical Discectomy and Fusion Implants.

Anterior cervical discectomy and fusion is commonly performed using an allograft or autograft implant and anterior screw-supported plate. There has been an increase in the use of standalone cage devices due to ease of use and studies suggesting a lower rate of acute postoperative dysphagia. We review our experience with standalone cage devices and identify risk factors, patterns of failure, and revision surgery approaches. We performed a retrospective case series of patients treated at a single tertiary care institution between March 2014 and March 2015. Inclusion criteria were aged 18-100 years, 1- or 2-level anterior cervical discectomy and fusion with a standalone cervical cage. Data collected included demographics, comorbidities, Charlson comorbidity score, primary diagnosis, and surgical characteristics. Descriptive statistics were performed for risk of readmission, implant failure, revision, and other complications. We identified 211 patients who met our study criteria. Average surgical time was 107 ± 43 minutes, with an estimated blood loss of 84.6 ± 32.4 mL. There were 11 (5.2%) readmissions. There were 10 (4.74%) implant failures (5 involving single-level surgery and 5 involving 2-level surgery), with 7 cases of pseudoarthrosis. Mechanisms of failure included a C5 body fracture, fusion in a kyphotic alignment after graft subsidence, and acute spondylolisthesis. Revision surgery after standalone anterior cervical implants can be complex. Posterior cervical fusion remains a valuable approach to avoid possible vertebral body fracture and loss of fusion area associated with the removal of implants secured through the endplates of adjacent vertebral bodies.

The Stand-Alone Cervical Cages with Integrated Screw Fixation: Results in 315 Consecutive Operated Levels

Introduction Background: Cervical disc disease at C2/3, C3/4 and C7/T1 is less common. Fusion with cages &amp; plating is the standard treatment at these levels and in multi-level disc disease. This is not without significant risks related to the need of larger exposure and anterior muscular dissection. Stand-alone cages with integrated screw fixation obviate the need for plating and larger exposure. Material and Methods To assess the exposure / cage related morbidities and fusion rates in Stand-Alone cervical cages with Integrated Screw Fixation. Design: Retrospective chart review. Subjects: 315 levels were operated in 253 patients from February 2009 to February 2015. Single and Multilevel cages were performed in 201 and 52 patients respectively. 201 of the 253 patients underwent single level discectomy with Stand-Alone cervical cages with Integrated Screw Fixation at C3/4 and C7/T1 levels. 52 patients underwent 114 multi-level discectomies with Stand-Alone cervical cages with Integrated Screw Fixation Results Operative time was shorter. There was no reported permanent exposure/ cage related morbidities in all operated levels. 3 patients with traumatic disc disruption required further surgery for lateral mass fixation. 12 patients had mild dysphagia that resolved during follow up with no patient having complains of dysphagia at 3- months follow up. Fusion rates were 95% at single level and 90% at multi-level discectomies at the last follow up. No patient required cage related surgical revision. Conclusion The current results support the use of Stand-Alone cervical cages with Integrated Screw Fixation especially at difficult levels at C3/4 and C7/T1 and in multi-level discectomies as it obviate the need for plating and larger exposure with less reported dysphagia and implant related complications.

Multilevel Cervical Arthroplasty versus Multilevel Fusion in Three-Level Cervical Disc Disease (Clinical and Radiological Outcomes)

Introduction The surgical treatment for cervical disc disease increased in the last decade using different surgical techniques. The percentage of the patients being surgically treated for three-level cervical disc disease remains small therefore the optimal surgical approach for these patients remains the subject of discussion. Multiple cervical disc arthroplasty, multilevel fusion, and hybrid procedures are among the options using the anterior approach. The aim of the study was to compare the multilevel cervical disc arthroplasty and multilevel fusion and compare clinical as well as the radiographic results in patients treated for three-level symptomatic cervical degenerative disc disease 2 years after the surgery. Methods Overall, 23 patients with three-level symptomatic cervical degenerative disc disease were treated with complete anterior cervical discectomy and either with ProDisc-C disc arthroplasty or with fusion using Cervios chronoOS prostheses (ACDF) or standalone cervical cages. Overall 8 multilevel arthroplasty and 14 ACDF's procedures were performed. Clinical outcomes were assessed before and 12 and 24 months after the procedure using neurological examination, the neck disability index (NDI) and visual analogue scale (VAS) for neck and arm pain, with 15% improvement in NDI and 20% in VAS defined as clinically significant. Comparison between both groups (arthroplasty and fusion group) was based on clinical outcomes using neurological examination, VAS, NDI, and patient's satisfaction. Preoperative and postoperative ROMs (range of motion) were evaluated by measuring the lateral and flexion–extension radiographs. Results Both groups had a statistically significant improvement in NDI and VAS for neck and arm pain ( p &lt; 0.05), 2 years after the surgery and the arthroplasty group had a slightly better improvement according to NDI (71.4% of patients in the arthroplasty group achieved ≥ 15% improvement in NDI and 67.5 of patients in ACDF group). The arthroplasty group showed faster recovery of C2 to C7 range of motion. There was a statistically significant difference in the C2 to C7 ROM between the two groups at 12 and 24 months postoperatively ( p &lt; 0.05). The ROM of the arthroplasty group approached the preoperative value at 12 months however it decreased again at 24 months. Conclusions Disc arthroplasty can be an effective alternative in the surgical treatment for the multilevel cervical disc disease, preserving segmental motion after surgery and providing improvement in pain and functional outcome for the patients. The right surgical treatment for the three-level disc disease remains the subject of discussion and more long-term follow-up studies will be needed to determine the definitive treatment.

Evaluation of Subsidence in Stand-Alone Cervical Cage: Incidence, Risk Factors and Effects on Clinical and Radiological Picture

Background Data: Anterior Cervical Discectomy and Fusion is the gold standard for treating cervical degenerative disc disease associated with radiculopathy and/or myelopathy. When indicated, surgery can achieve neural tissuedecompression and biomechanical stabilization through bony fusion. One of the known complications of stand-alone anterior cervical cage is cage subsidence. Published literature however, contains mixed results in terms of rate of cagesubsidence, loss of lordosis and its clinical effects. Purpose: We report our experience in stand-alone anterior cervical cage, our subsidence rate and its effect on loss of lordosis and clinical picture Study Design: Retrospective clinical case study. Patients and Methods: we inserted seventy-two cervical cages (in fifty patients), who had Anterior Cervical Discectomy and Fusion using a stand-alone polyetheretherketone (PEEK) cage under our care. We recorded the self-reported Visual Analogue Score for arm and neck pain and measured the total intervertebral height/disc space or cage ratio, segmental Cobb angle, the distance between the anterior rim of the cage and the anterior vertebral body line, superior or inferior end plate violation and anterior or posterior cage migration on lateral X ray film preoperatively and on each follow up visit (day 1, 7-21 days, 3, and 6 months). Results: Our cage subsidence rate in the studied sample was 23.6% in 6 months (17 out of 62 cages subsided). We found a statistically significant correlation between immediate postoperative disc height and subsidence (the more distraction we applied to the disc space the more likely subsidence would happen). Cage subsidence did not increase the incidence of recurrence of radicular, myelopathic symptoms or neck pain although it resulted in significant loss of the segmental Cobb angle. Conclusions: Disc space over-distraction in stand-alone anterior cervical cage significantly increases the risk of subsidence. Subsidence significantly affects thesegmental Cobb angle but not the clinical outcome. (2015ESJ077)

Development of a Low-Cost Polymethylmethacrylate Stand-Alone Cervical Cage: Technical Note

Stand-alone cervical cages aim to provide primary stability, yield solid fusion in the long-term course, and maintain physiologic alignment. However, many implants designed for these purposes fail in achieving these goals. Following implantation, relatively high rates of cage subsidence and failure of disc height maintenance may lead to cervical kyphosis and poor alignment of the cervical spine. At the same time, costs for cage implantation are relatively high compared with their unfavorable radiologic performance. Thus the aim of the study was to develop and test mechanically a low-cost polymethylmethacrylate (PMMA) cage with similar mechanical and procedural properties compared with a commercial polyetheretherketone (PEEK) cage. Following determination of the cage design, a casting mold was developed for the production of PMMA cages. Nine cages were produced and compared with nine PEEK cages using static compression tests for 0 and 45 degrees according to the recommendations of the American Society for Testing and Materials. Mean compressive yield strength, mean yield displacement, mean tensile strength, and mean stiffness were determined. At 0 degrees axial compression, the mean compressive yield strength, mean displacement, and mean tensile strength of the PMMA cage was significantly higher compared with the PEEK cage (p < 0.001). Stiffness of both implants did not differ significantly (p = 0.903). At 45 degrees axial compression, PEEK cages could not be investigated because slipping of the holding fixture occurred. Under these conditions, PMMA cages showed a mean compressive yield strength of 804.9 ± 60.5 N, a mean displacement of 0.66 mm ± 0.05 mm, a mean tensile strength of 7.92 ± 0.6 N/mm(2), and a mean stiffness of 1,228 ± 79.4 N/mm. The newly developed PMMA cage seems to show similar to superior mechanical properties compared with the commercial PEEK cage. Considering a preparation time of only 10 minutes and the low price for the PMMA material, the cost-benefit ratio clearly points to the use of the PMMA cage. However, clinical effectiveness has to be proven in a separate study.

Answer to the ?Letter to the editor? of Dr. Wolfgang B�rm

Dear Dr Borm, We would like to thank you for your comments that show you took great interest in our paper. When the first report on stand-alone lumbar cages came out, this method was obviously hailed as the answer to treatment of axial low back pain. However, further follow-ups and critical analyses showed that stand-alone lumbar interbody cages subsided, did not restore anatomic lumbar lordosis and had pseudarthroses. Some authors recommended that lumbar cages should not be inserted into the lumbar spine in a stand-alone fashion. However improved cage technology and further refinements to the surgical techniques have ensured that lumbar cages are here to stay. The biomechanics in the cervical spine are somewhat different and one would expect to see fusion more easily in the cervical spine than in the lumbar spine as simple cervical discectomy leads to fusion in a significant number of cases. Artificial discs that are supposed to maintain motion in the cervical spine have also been associated with spontaneous fusion in a number of cases. You criticise our paper because we do not give any clear conclusions as to the use of stand-alone cages in the cervical spine. As we have already written, our series was small and specifically studied subsidence of the cervical cages inserted in a stand-alone fashion even though the outcome of our patients was favourable in most cases. At the time of writing the paper, we did not have any of the most recently available literature on cage subsidence. A review of the most recent literature on the subject (including the two papers you quote) shows that it is recognized that cage subsidence may occur after the insertion of stand-alone cervical cages, and we are happy to have been the first ones to have brought this up in the form of a warning (20% rate of cage subsidence in the Payer series, 35% rate in the Thome series, 50% rate in the Kanayama series, 62% rate in our series) [1, 2, 3]. Payer is currently changing the size of its cage and its design because of the high rate of subsidence. The available literature on anterior cervical discectomy with or without fusion mostly reports excellent clinical results with resolution of the symptoms. The purpose of adding an instrumentation or interbody cage after anterior discectomy is threefold: to achieve a better fusion rate, restore anatomic segmental lordosis and restore intervertebral disc height. The findings of all the available literature and our series showed that no segmental motion was present on the flexion-extension X-rays after the use of stand-alone cervical cages. So we can therefore assume that stand-alone cervical cages fuse in the large majority of cases, as we were able to assume in our series. As far as segmental lordosis is concerned, there is obviously not enough information in the literature, and it is possible to debate the value of cylindrical or rectangular cages that do not restore anatomic lordosis. Lastly, subsidence of stand-alone cervical cages is now a well recognized problem in the literature. This rate of subsidence does not seem to affect the initial clinical result although one of the targets of the cage (restoration of disc space height) is not achieved in a large number of cases. However, all these clinical results are short-term follow-up results, and anterior discectomy alone or non-instrumented anterior fusion with dowel graft led to segmental kyphosis and loss of height in a significant number of cases. Such adverse effects were sometimes only observed after one or two decades after the initial surgery. Therefore we do not condemn cage technology in the cervical spine, but maintain our initial warning that many available stand-alone cervical cages may be associated with subsidence, as is now well documented in the literature. Long-term follow-up of such subsidence should determine whether this has a clinical impact on the patient’s symptoms and adjacent segments of the cervical spine. Lastly, I would like to urge you not to feel guilty about your previous use of anterior cervical cages. I suggest you document your cases and look at the clinical outcome of your patients, as well as the radiographic anatomic parameters of segmental lordosis, intervertebral disc space height and cage subsidence.

Subsidence of stand-alone cervical cages in anterior interbody fusion: warning.

Anterior cervical decompression and fusion with anterior plating of the cervical spine is a well-accepted treatment for cervical radiculopathy. Recently, to minimise the extent of surgery, anterior interbody fusion with cages has become more common. While there are numerous reports on the primary stabilising effects of the different cervical cages, little is known about the subsidence behaviour of such cages in vivo. We retrospectively reviewed eight patients with cervical radiculopathy operated upon with anterior discectomy and fusion with a stand-alone titanium cervical cage. During surgery, only the cartilage portion of the end plate was removed and the cages were filled with autologous cancellous bone graft from the iliac crest. To assess possible subsidence or migration, three different radiographic measurements in the sagittal plane were taken for each case, postoperatively and at the latest follow-up. Subsidence was defined as any change in at least one of our parameters of at least 3 mm. Follow-up time was 12-18 months (average 15 months). Five of the nine fused levels had radiological signs of cage subsidence. No posterior or anterior migration was observed. However, subsidence did not correlate with clinical symptoms in four of the five patients. The remaining patient with signs of subsidence, whose neck pain and neurologic symptoms had regressed in the early postoperative course, suffered recurrence of radiculopathy 6 months after the surgery. Her symptoms were explained by the subsidence of the cage and the subsequent foraminal stenosis observed on the magnetic resonance imaging (MRI) scan. At 15 months' follow-up, her cage was broken. Our preliminary results, so far limited in number, represent a serious warning to the proponents of stand-alone cervical cages