Stand-alone Cage Research Articles

Clinical and Radiological Outcomes of Anchored Stand-Alone Cage Compared to Conventional Plating in Multilevel Anterior Cervical Discectomy and Fusion: A Systematic Review

Clinical and Radiological Outcomes of Anchored Stand-Alone Cage Compared to Conventional Plating in Multilevel Anterior Cervical Discectomy and Fusion: A Systematic Review

Cervical Lordosis Correction and Segmental Height in Anterior Cervical Surgeries; The Role of Implant Choice

This study aims to compare the impact of three surgical techniques-stand-alone cage placement (SAC), anterior cervical plate (ACP) fixation, and total disc replacement (TDR)-on cervical lordosis restoration and segmental height after anterior cervical discectomy at C5-6 level. To eliminate the effect of lordosis between different levels, patients operated on at the same level were included in the study. Restoring cervical lordosis is crucial for improving patient outcomes, including pain reduction and preventing mechanical complications. A retrospective screening of 89 patients who underwent single-level C5-6 surgery between 2011 and 2021 was analyzed. Patients were categorized into three groups based on the surgical technique used: SAC, ACP, or TDR. Lordotic angles and segmental heights were measured preoperatively, first-month follow-up, and at the 24-month follow-up. Statistical analysis was conducted using the Wilcoxon Signed Rank test and ANOVA, with a significance threshold set at P<.05. All three techniques resulted in significant early and late postoperative increases in both global and segmental lordosis. The early postoperative height gain was most pronounced in the ACP group. However, no significant differences in lordosis or height preservation were observed among the groups at the 24-month follow-up. These findings align with previous studies, indicating comparable long-term outcomes across these surgical approaches. Stand-alone cage placement, anterior cervical plate fixation, and total disc replacement all effectively restore cervical lordosis and segmental height after anterior cervical discectomy at the C5-6 level. Despite early differences, the long-term results were similar, suggesting that the choice of technique should be based on individual patient needs and specific surgical considerations.

Revision Surgery after Single Level Anterior Cervical Discectomy and Fusion With Plate vs Stand-Alone Cage over 2 to 5 Year Follow-Up.

retrospective study. To investigate the incidence of all-cause revision surgery between plated vs stand-alone cage constructs for single level ACDF. We retrospectively analyzed a commercial insurance claims database. Patients 18-65years-old were included if they underwent single-level inpatient ACDF (defined with CPT codes) from 2010 - 2018, with a minimum of 2-year continuous insurance enrollment. The primary independent variable was the use of anterior plating vs zero profile device or stand-alone cage. Synthetic (ie, metal, PEEK, etc.) vs allograft interbody was a secondary independent variable. The primary outcome variable was revision cervical arthrodesis after the index operation. In total, 21092 patients undergoing single-level inpatient ACDF were included. 10.0% received a stand-alone cage during the index operation. Mean follow-up duration was 4.5years. Revision arthrodesis occurred in 8.2% of patients overall, at a mean of 2.4years after the index surgery. Patients with anterior plating had a lower rate of all-cause revision surgery in unadjusted (overall rate 8.1% vs 9.6%, P = 0.0185) and adjusted analysis (OR 0.78, P = 0.0016) vs stand-alone cages. Patients with stand-alone cages had higher rates of revision with a posterior approach than did patients with plated constructs. In sub-analysis, the combination of a stand-alone interbody device with an allograft had significantly higher odds of revision than other combinations of devices. Among commercially insured patients ≤65years-old undergoing single-level ACDF, anterior plating was associated with a reduced incidence of revision surgery compared to stand-alone cages within the follow up period of our study.

Letter to the Editor Regarding: “Assessing Surgical Outcomes for Cage Plate System versus Stand-Alone Cage in Anterior Cervical Discectomy and Fusion: A Systematic Review and Meta-Analysis”

Letter to the Editor Regarding: “Assessing Surgical Outcomes for Cage Plate System versus Stand-Alone Cage in Anterior Cervical Discectomy and Fusion: A Systematic Review and Meta-Analysis”

Radiographic fusion and subsidence rates for stand-alone cage versus anterior cage-plate construct in ACDF

Study DesignRetrospective cohort BackgroundThe addition of an anterior cervical plate to a structural allograft during ACDF is thought to provide extra stability and enhance fusion, but it may increase the risk of complications like dysphagia. Stand-alone cages were designed to provide this extra stability without the need for the plate, but these may increase a patient's risk of subsidence, cervical dislocation, and cervical kyphosis. The purpose of this study was to assess reoperation rates and radiographic outcomes during follow-up longer than 6 months for patients who underwent ACDF with a cage and plate compared to stand-alone cage. MethodsACDF cases were retrospectively identified for four fellowship trained spine surgeons from 2016 – 2020 from two academic hospitals. A total of 57 stand-alone structural allograft constructs were matched via propensity scoring with a cohort of 65 patients with plate-secured structural allograft constructs. The primary outcome was reoperation rate within the follow-up period and secondary outcomes included complications, operative characteristics, readmission within 30 days, reoperation within 30 days and within follow-up, and radiographic outcomes. Immediate post-operative radiographs were compared to final follow-up radiographs at least 6 months post-operation to assess for evidence of subsidence, fusion, and change in cervical kyphosis using the Cobb angle technique. ResultsThere were 5 patients (5.26 %) in the stand-alone cohort and 4 patients (3.15 %) in the plate cohort that had cervical reoperation at any time in follow-up (P = 0.83). At final follow-up, 58 patients (92.1 %) in the plate group and 37 patients (75.5 %) in the stand-alone group had radiographic evidence of fusion (P = 0.015). There were 38 patients (77.6 %) in the stand-alone group and 29 patients (46 %) in the plate group with evidence of subsidence (P = 0.0007). Patients with subsidence had a greater change in kyphosis angle at final follow-up and this change was significantly decreased in the plate group compared to the stand-alone group. ConclusionThe use of anterior cage-plate constructs in ACDF produces higher rates of fusion and lower rates of subsidence than stand-alone cage constructs. Subsidence significantly increases the change in kyphosis angle between post-op and final follow-up, and the presence of a spanning plate significantly reduces this angle change compared to stand-alone cages. There were no statistically significant differences in reoperation rates, regardless of radiographic evidence of subsidence.

A New Method to Evaluate Pressure Distribution Using a 3D-Printed C2-C3 Cervical Spine Model with an Embedded Sensor Array

Cervical degenerative disc diseases such as myelopathy and radiculopathy often require conventional treatments like artificial cervical disc replacement or anterior cervical discectomy and fusion (ACDF). When designing a medical device, like the stand-alone cage, there are many design inputs to consider. However, the precise biomechanics of the force between the vertebrae and implanted devices under certain conditions require further investigation. In this study, a new method was developed to evaluate the pressure between the vertebrae and implanted devices by embedding a sensor array into a 3D-printed C2-C3 cervical spine. The 3D-printed cervical spine model was subjected to a range of axial loads while under flexion, extension, bending and compression conditions. Cables were used for the application of a preload and a robotic arm was used to recreate the natural spine motions (flexion, extension, and bending). To verify and predict the total pressure between the vertebrae and the implanted devices, a 3D finite element (FE) numerical mathematical model was developed. A preload was represented by applying 22 N of force on each of the anterior tubercles for the C2 vertebra. The results of this study suggest that the sensor is useful in identifying static pressure. The pressure with the robot arm was verified from the FE results under all conditions. This study indicates that the sensor array has promising potential to reduce the trial and error with implants for various surgical procedures, including multi-level artificial cervical disk replacement and ACDF, which may help clinicians to reduce pain, suffering, and costly follow-up procedures.

Anterior cervical discectomy and fusion (ACDF) with and without plating: A comparison of radiological and clinical outcomes.

Treatment for degenerative disc disease of the cervical spine primarily aims to decompress neural structures and preserve the former height of the disc space and foramina. Popular methods include anterior cervical discectomy and fusion (ACDF) using cages with plates or without plates (standalone cages). However, it is still debatable whether a plate is necessary for enhanced treatment outcomes. This paper reviews current literature reports, adding insights from the authors' experience. A literature search was performed with keywords related to ACDF with or without cervical plating. We analyzed the titles and abstracts to identify all potentially relevant studies. Out of these, a total of 28 original research and 5 systematic reviews/meta-analyses met our inclusion criteria. The success of surgery for cervical disc disease depends fundamentally on the appropriate decompression of neural structures. This is the main determinant of postoperative clinical improvement measured according to scales capturing changes in pain intensity and quality of life. An ideal replacement for natural components of the human body does not exist, even though more and more refined solutions are developed every year. A comparison of treatment outcomes using non-plated (standalone) cages and cage + plate systems requires separate analysis of radiological and clinical outcomes. Both methods have their advantages and disadvantages. Radiological outcomes are slightly better with cage + plate systems, and clinical outcomes are comparable.

Comparing zero-profile and conventional cage and plate in anterior cervical discectomy and fusion using finite-element modeling

Conventional cage and plate (CCP) implants usually used in ACDF surgery, do have limitations such as the development of postoperative dysphagia, adjacent segment degeneration, and soft tissue injury. To reduce the risk of these complications, zero-profile stand-alone cage were developed. We used finite-element modeling to compare the total von Mises stress applied to the bone, disc, endplate, cage and screw when using CCP and ZPSC implants. A 3-dimensional FE (Finite element) analysis was performed to investigate the effects of the CCP implant and ZPSC on the C3 ~ T1 vertebrae. We confirmed that the maximum von Mises stress applied with ZPSC implants was more than 2 times greater in the endplate than that applied with CCP implants. The 3D analysis of the ZPSC model von Mises stress measurements of screw shows areas of higher stress in red. Although using ZPSC implants in ACDF reduces CCP implant-related sequalae such as dysphagia, we have shown that greater von Mises stress is applied to the endplate, and screw when using ZPSC implants. This may explain the higher subsidence rate associated with ZPSC implant use in ACDF. When selecting an implant in ACDF, surgeons should consider patient characteristics and the advantages and disadvantages of each implant type.

Anterior Cervical Discectomy and Fusion With Structural Allograft is Associated With Lower Postoperative Health Care Utilization and Reoperations Compared With Cage Implants.

Implants represent a large component of surgical cost, with several available options for anterior cervical discectomy and fusion (ACDF). Rising ACDF volume highlights the need for accurate cost characterization among implant configurations to inform efficient utilization. A cohort study of patients who underwent 1-level or 2-level ACDF in 2017 was conducted using the MarketScan national insurance databases, which contain deidentified clinical and financial data. Implant configurations included plate with cage, standalone cage, and plate with structural allograft. Patients who switched insurance providers within 2 years after surgery or underwent concurrent posterior cervical surgery, cervical disk arthroplasty, or cervical corpectomy were excluded. A combined plate/cage and standalone cage group was compared with the allograft group followed by the comparison of the plate/cage and standalone cage groups. In total, 30-day, 90-day, and 2-year aggregate costs; component costs of physical therapy, injections, medications, psychological treatment, and subsequent spine surgery; and reoperation rates were evaluated. Of 1723 patients identified, 360 (20.9%) underwent surgery with plate/cage, 184 (10.7%) with standalone cage, and 1179 (68.4%) with allograft. Aggregate costs were lower in the allograft group compared with the combined cage group at 90 days ($36 428 vs $39 875, P = .04) and 2 years ($64 951 vs $74 965, P = .005) postoperatively. There were no significant differences in aggregate costs between the plate/cage and standalone cage groups. The 2-year reoperation rate was higher in the combined cage compared with the allograft group (23.9% vs 10.9%, P < .001) and was also higher in the standalone cage compared with the plate/cage group (32.0% vs 19.7%, P = .002). Compared with alternative ACDF constructs, allograft is associated with lower postoperative costs and reoperation rates. Although costs are similar, reoperation rates are lower with plate/cage constructs compared with those of standalone cages. Surgeons should consider these financial and clinical differences when selecting implant configurations.

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

Study designA retrospective study. BackgroundConventional 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. ObjectiveTo assess the clinical and radiological outcomes of hybrid fixation with SSC and CCP against conventional CCP in 3-level ACDF. MethodA 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. ResultsNo 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. ConclusionThe hybrid fixation achieved comparable clinical outcomes against CCP fixation, indicating that hybrid fixation is an alternative procedure in 3-level ACDF.

Designing an anatomical contour titanium 3D-printed oblique lumbar interbody fusion cage with porous structure and embedded fixation screws for patients with osteoporosis.

This study aimed to design an anatomical contour metal three-dimensional (3D)-printed oblique lateral lumbar interbody fusion (OLIF) cage with porous (lattices) structure and embedded screw fixation to enhance bone ingrowth to reduce the risk of cage subsidence and avoid the stress-shielding effect. Finite element (FE) analysis and weight topology optimization (WTO) were used to optimize the structural design of the OLIF cage based on the anatomical contour morphology of patients with osteoporosis. Two oblique embedded fixation screws and lattice design with 65% porosity and average pore size of 750 μm were equipped with the cage structure. The cage was fabricated via metal 3D printing, and static/dynamic compression and compressive-shear tests were performed in accordance with the ASTM F2077-14 standard to evaluate its mechanical resistance. On FE analysis, the OLIF cage with embedded screw model had the most stability, lowest stress values on the endplate, and uniform stress distribution versus standalone cage and fixed with lateral plate under extension, lateral flexion, and rotation. The fatigue test showed that the stiffnesses/endurance limits (pass 5 million dynamic test) were 16,658 N/mm/6000 N for axial load and 19,643 N/mm/2700 N for compression shear. In conclusion, an OLIF cage with embedded fixation screws can be designed by integrating FE and WTO analysis based on the statistical results of endplate morphology. This improves the stability of the OLIF cage to decrease endplate destruction. The complex contour and lattice design of the OLIF cage need to be manufactured via metal 3D printing; the dynamic axial compression and compressive-shear strengths are greater than that of the U.S. Food and Drug Administration (FDA) standard.

A prospective functional outcome of stand-alone cage in cervical disc prolapses following discectomy

Introduction and Aim: Anterior cervical decompression and fusion (ACDF) is the go-to treatment for degenerative cervical illness that causes persistent radiculopathy. It has been suggested that a separate cage be used so that the patient's plates do not get damaged. This research aims to examine the radiological and functional results of discectomy and cage placement in patients with cervical disc prolapse. Materials and Methods: This study prospectively assessed patients who had anterior cervical decompression and fusion using a freestanding cage. Patients' pain levels on a Visual Analog Scale (VAS) and their level of impairment as measured by the Neck impairment Index (NDI) were taken before surgery. Post-operative pain assessment, looked out for cage related complications during follow up period at 3rd and 6th month post operatively by radiological evaluation. Results: Median age of neutral group and kyphosis was 45 and 34 respectively. Maximum number of patients had C5 - C6 IVDP. Median Cobb’s angle was higher in kyphosis group as compared to neutral group. Before surgery, at 10 days, and at 3 and 6 months after surgery, the kyphosis group had a higher median VAS and NDI score than the neutral group. Conclusion: The present study demonstrated that ACDF using a single cage successfully reduced the patient's preoperative neck pain and associated disability. The advantages of ACDF with a single cage include a shorter surgical time, better cervical lordosis and disc height, and no cage sinking. As a result, cage fusion as a stand-alone treatment option for cervical degenerative disease is likely to be regarded as a viable option.

Biomechanical Analysis of Double-Level Oblique Lumbar Fusion with Different Types of Fixation: A Finite Element-Based Study.

One well-liked less invasive procedure is oblique lumbar interbody fusion (OLIF). The biomechanical characteristics of double-level oblique lumbar interbody fusion in conjunction with various internal fixations are poorly understood. The purpose of this study was to clarify the biomechanical characteristics of double-level oblique lumbar interbody fusion for osteoporosis spines using various internal fixation techniques. Based on CT scans of healthy male volunteers, a complete finite element model of osteoporosis in L1-S1 was established. After validation, L3-L5 was selected as the surgical segment to construct four surgical models: (a) two stand-alone cages (SA); (b) two cages with unilateral pedicle screws (UPS); (c) two cages with bilateral pedicle screws (BPS); and (d) two cages with bilateral cortical bone trajectory screws (CBT). Segmental range of motion (ROM), cage stress, and internal fixation stress were studied in all surgical models and compared with the intact osteoporosis model. The SA model had a minimal reduction in all motions. The CBT model had the most noticeable reduction in flexion and extension activities, while the reduction in the BPS model was slightly less than that in the CBT model but larger than that in the UPS model. The BPS model had the greatest limitation in left-right bending and rotation, which was greater than the UPS and CBT models. CBT had the smallest limitation in left-right rotation. The cage stress of the SA model was the highest. The cage stress in the BPS model was the lowest. Compared with the UPS model, the cage stress in the CBT model was larger in terms of flexion and LB and LR but slightly smaller in terms of RB and RR. In the extension, the cage stress in the CBT model is significantly smaller than in the UPS model. The CBT internal fixation was subjected to the highest stress of all motions. The BPS group had the lowest internal fixation stress in all motions. Supplemental internal fixation can improve segmental stability and lessen cage stress in double-level OLIF surgery. In limiting segmental mobility and lowering the stress of cage and internal fixation, BPS outperformed UPS and CBT.

BIOMECHANICAL STUDY OF LATERAL LUMBAR INTERBODY FUSION VERSUS A POSTERIOR FIXATION WITH PEDICLE SCREWS AND RODS USING A HUMAN CADAVERIC MODEL

Lateral lumbar interbody fusion (LLIF) has biomechanical advantages due to the preservation of ligamentous structures (ALL/PLL), and optimal cage height afforded by the strength of the apophyseal ring. We compare the biomechanical motion stability of multiple levels LLIF (4 segments) utilising PEEK interbody 26mm cages to stand-alone cage placement and with supplemental posterior fixation with pedicle screw and rods.Six lumbar human cadaver specimens were stripped of the paraspinal musculature while preserving the discs, facet joints, and osteoligamentous structures and potted. Specimens were tested under 5 conditions: intact, posterior bilateral fixation (L1-L5) only, LLIF-only, LLIF with unilateral fixation and LLIF with bilateral fixation. Non-destructive testing was performed on a universal testing machine (MTS Systems Corp) to produce flexion-extension, lateral-bending, and axial rotation using customized jigs and a pulley system to define a non-constraining load follower. Three-dimensional spine motion was recorded using a motion device (Optotrak).Results are reported for the L3-L4 motion segment within the construct to allow comparison with previously published works of shorter constructs (1-2 segments). In all conditions, there was an observed decrease in ROM from intact in flexion/extension (31%-89% decrease), lateral bending (19%-78%), and axial rotation (37%-60%). At flexion/extension, the decreases were statistically significant (p&lt;0.007) except for stand-alone LLIF. LLIF+unilateral had similar decreases in all planes as the LLIF+bilateral condition. The observed ROM within the 4-level construct was similar to previously reported results in 1-2 levels for stand-alone LLIF and LLIF+bilateral.Surgeons may be concerned about the biomechanical stability of an approach utilizing stand-alone multilevel LLIF. Our results show that 4-level multilevel LLIF utilizing 26 mm cages demonstrated ROM comparable to short-segment LLIF. Stand-alone LLIF showed a decrease in ROM from the intact condition. The addition of posterior supplemental fixation resulted in an additional decrease in ROM. The results suggest that unilateral posterior fixation may be sufficient.

Clinical and imaging outcomes of self-locking stand-alone cages and anterior cage-with-plate in three-level anterior cervical discectomy and fusion: a retrospective comparative study

BackgroundAnterior cervical discectomy and fusion has been considered standard management for cervical myelopathy and radiculopathy. However, the option of using self-locking stand-alone cages or cage-with-plate in three-level anterior cervical discectomy and fusion still remains controversial. The aim of this study was to evaluate the clinical and imaging outcomes of the two procedures in multilevel anterior cervical discectomy and fusion.MethodsSixty-seven patients who underwent three-level anterior cervical discectomy and fusion were enrolled in this study, of which 31 patients underwent surgery using self-locking stand-alone cages (group cage) and 36 patients using cage-with-plate (group plate). For the evaluation of clinical outcomes, modified Japanese Orthopedic Association scores, visual analogue scale for neck pain, neck disability index, Odom’s criteria and dysphagia status were measured. Imaging outcomes were evaluated by cervical sagittal angle, fusion segmental Cobb’s angle, fusion segmental height, range of motion, cage subsidence rate, fusion rate and adjacent segment degeneration. Statistical analyses were performed using the SPSS software (version 19.0).ResultsBoth groups showed improvement in modified Japanese Orthopedic Association scores, visual analogue scale for neck pain and neck disability index, after surgery, and there was no significant difference between the groups. The occurrence rate of dysphagia is significantly lower in the group cage compared with the group plate (p < 0.05). The postoperative cervical sagittal angle, fusion segmental Cobb’s angle, fusion segmental height and cage subsidence rate in the group plate were significantly superior to that in the group cage (p < 0.05). However, the rate of adjacent segment degeneration was significantly lower in the group cage compared with the group plate (p < 0.05). Both groups showed no significant difference in terms of fusion rate (p > 0.05).ConclusionsThe self-locking stand-alone cages are effective, reliable and safe in anterior cervical discectomy and fusion for the treatment of cervical myelopathy and radiculopathy. Self-locking stand-alone cages showed a significantly lower rate of dysphagia and adjacent segment degeneration, while anterior cervical cage-with-plate could provide stronger postoperative stability and maintain better cervical spine alignment.

Multilevel anterior cervical fusion with standalone cage or cage-and-plate after cervical discectomy: Benefits and drawbacks

PurposeMultilevel anterior cervical discectomy and fusion (ACDF), especially two-level ACDF, has been usually performed in the cervical degenerative disease, and the incidence rate of complications is controversial. This study aimed to compare the outcomes of ACDF approach with cage alone and with plate fixation in multilevel discectomy. MethodsPatients who had undergone multilevel ACDF by the Smith-Robinson methods were included from 2018 to 2020. Data were collected using a questionnaire containing demographic characteristics, surgical complications, and outcome. All the patients were followed for 18 months post-surgery. Visual Analogue Scale (VAS), Neck Disability Index (NDI) and Nurick Grading scale were used to measure the pain degree, neck pain effect, and myelopathy grade, respectively. Bone fusion rate, subsidence and instrument failure were checked through radiography. Data were analyzed using SPSS, and the significant level was considered 0.05. Results24 patients were included. There was no significant difference between the mean blood losses in the two groups. The rate of subsidence was much higher in group B after 18 months (60% vs 14.3%). As to the VAS score, NDI, and Nurick scale, trend change overtime was significantly improved in each group, but there was no significant difference between the groups. There was no significant difference between the two groups regarding bony fusion rate. DiscussionACDF with plate leads to a more prolonged surgery with no significant benefits. Stand-alone cage approach could be suggested as the gold standard for anterior cervical discectomy.

Computational comparison of anterior lumbar interbody fusion and oblique lumbar interbody fusion with various supplementary fixation systems: a finite element analysis

Background and objectiveAnterior lumbar interbody fusion (ALIF) and oblique lumbar interbody fusion (OLIF) have shown a great surgical potential, while it has always been controversial which surgical approach and which type of fixation system should be selected. This study investigated the biomechanical response of ALIF and OLIF with various supplementary fixation systems using the finite element method.Materials and methodsLumbar L4–L5 ALIF and OLIF models stabilized by different supplementary fixation systems (stand-alone cage, integrated stand-alone cage, anterior plate, and bilateral pedicle screw) were developed to assess the segmental range of motion (ROM), endplate stress (EPS), and screw-bone interface stress (SBIS).Experimental resultsALIF showed lower ROM and EPS than OLIF in all motion planes and less SBIS in the most of motion planes compared with OLIF when the anterior plate or pedicle screw was used. ALIF induced higher ROM, while lower EPS and SBIS than OLIF in the majority of motion planes when integrated stand-alone cage was utilized. Using a stand-alone cage in ALIF and OLIF led to cage migration. Integrated stand-alone cage prevented the cage migration, whereas caused significantly larger ROM, EPS, and SBIS than other fixation systems except for the rotation plane. In the most of motion planes, the pedicle screw had the lowest ROM, EPS, and SBIS. The anterior plate induced a slightly larger ROM, EPS, and SBIS than the pedicle screw, while the differences were not significant.ConclusionALIF exhibited a better performance in postoperative segmental stability, endplate stress, and screw-bone interface stress than OLIF when the anterior plate or the pedicle screw was used. The pedicle screw could provide the greatest postoperative segmental stability, less cage subsidence incidence, and lower risk of fixation system loosening in ALIF and OLIF. The anterior plate could also contribute to the stability required and fewer complications, while not as effectively as the pedicle screw. Extreme caution should be regarded when the stand-alone cage is used due to the risk of cage migration. The integrated stand-alone cage may be an alternative method; however, further optimization is needed to reduce complications and improve postoperative segmental stability.

Standalone cage for the treatment of symptomatic adjacent segment stenosis in the degenerative cervical spine

Standalone cage for the treatment of symptomatic adjacent segment stenosis in the degenerative cervical spine

Analysing the clinical relevance and impact of subsidence seen with standalone cages for cervical disc surgeries – A study of fusion rates in 118 patients

Analysing the clinical relevance and impact of subsidence seen with standalone cages for cervical disc surgeries – A study of fusion rates in 118 patients

Anterior cervical discectomy and fusion with zero-profile versus stand-alone cages for two-level cervical spondylosis: A retrospective cohort study.

To assess the mid-long-term clinical and radiological outcomes of zero-profile (ZP) compared with stand-alone (ST) cages for two-level anterior cervical discectomy and fusion (ACDF). We included 77 patients (39 women and 38 men) who underwent two-level ACDF between May 5, 2016, and May 5, 2020, and who were followed up for at least 1 year. The subjects were divided into the ST (n = 38) and ZP (n = 39) group. For the evaluation of functional status, Japanese Orthopedic Association (JOA), Neck Disability Index (NDI), and Visual Analogue Scale (VAS) scores were used. Additionally, radiological outcomes and procedure complications were observed at final follow-up. Both groups had excellent clinical outcomes at the final follow-up. There were no significant intergroup (ZP vs. ST) differences in the fusion rate (91.02% vs. 90.79%, P > 0.05) and postoperative dysphagia (15.4% vs. 2.6%, P = 0.108). However, the disc height at the final follow-up in the ZP group was higher than that in the ST group (6.86 ± 0.84 vs. 6.17 ± 1.03, P = 0.002). The ZP group accomplished a lower loss of cervical lordosis (18.46 ± 4.78 vs. 16.55 ± 4.36, P = 0.071), but without reaching statistical significance. ACDF with either ZP or ST cages turns out to be a dependable strategy for two-level ACDF in terms of clinical results. However, compared with the ST, the ZP cage may achieve a significantly lower loss of disc height.