Two-level Anterior Cervical Discectomy Research Articles

The Effect of Patient Resilience on Postoperative Scores After One and Two-level Anterior Cervical Discectomy and Fusion

ObjectiveThe purpose is to investigate the association between resilience and outcomes of pain and neck-related disability after single- and two-level anterior cervical discectomy and fusion (ACDF). MethodsPatients who underwent single- or two-level ACDF were sent a survey between six months and two years following surgery. The survey included the Brief Resilience Scale (BRS), Visual Analogue Scale (VAS) for pain, Neck Disability Index (NDI), and Pain Self-Efficacy Questionnaire (PSEQ-2). Patients completed the VAS and NDI twice, once describing preoperative pain and disability and once describing current pain and disability. Respondents were classified as high resilience (HR), medium resilience (MR), or low resilience (LR). Demographics, PSEQ-2 scores, pre- and postoperative VAS and NDI scores, and change in VAS (ΔVAS) and NDI (ΔNDI) scores were compared between groups. ResultsThirty-three patients comprised the HR group, 273 patients comprised the MR group, and 47 patients comprised the LR group. All groups demonstrated postoperative improvement in VAS and NDI scores that exceeded previously established MCID values. The HR group demonstrated greater improvement in pain compared to the LR group (ΔVAS: -5.8 for HR vs -4.4 for LR, p=0.05). Compared to the MR group, the LR group demonstrated greater postoperative pain (VAS: 3.2 for LR vs 2.5 for MR, p=0.02) and disability (NDI: 11.9 for LR vs 8.6 for MR, p=0.02). ConclusionsPatients demonstrated improvement in pain and neck-related disability after single- and two-level ACDF, regardless of resilience score. Patients with greater resilience may be expected to demonstrate more improvement in pain after ACDF.

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

Systematic literature review. 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). 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. 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%). 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.

Biomechanical study of anterior transpedicular root screw intervertebral fusion system of lower cervical spine: a finite element analysis.

Background: The cervical anterior transpedicular screw (ATPS) fixation technology can provide adequate stability for cervical three-column injuries. However, its high risk of screw insertion and technical complexity have restricted its widespread clinical application. As an improvement over the ATPS technology, the cervical anterior transpedicular root screw (ATPRS) technology has been introduced to reduce the risk associated with screw insertion. This study aims to use finite element analysis (FEA) to investigate the biomechanical characteristics of a cervical spine model after using the novel ATPRS intervertebral fusion system, providing insights into its application and potential refinement. Methods: A finite element (FE) model of the C3-C7 lower cervical spine was established and validated. After two-level (C4-C6) anterior cervical discectomy and fusion (ACDF) surgery, FE models were constructed for the anterior cervical locked-plate (ACLP) internal fixation, the ATPS internal fixation, and the novel ATPRS intervertebral fusion system. These models were subjected to 75N axial force and 1.0 Nm to induce various movements. The range of motion (ROM) of the surgical segments (C4-C6), maximum stress on the internal fixation systems, and maximum stress on the adjacent intervertebral discs were tested and recorded. Results: All three internal fixation methods effectively reduced the ROM of the surgical segments. The ATPRS model demonstrated the smallest ROM during flexion, extension, and rotation, but a slightly larger ROM during lateral bending. Additionally, the maximum bone-screw interface stresses for the ATPRS model during flexion, extension, lateral bending, and axial rotation were 32.69, 64.24, 44.07, 35.89MPa, which were lower than those of the ACLP and ATPS models. Similarly, the maximum stresses on the adjacent intervertebral discs in the ATPRS model during flexion, extension, lateral bending, and axial rotation consistently remained lower than those in the ACLP and ATPS models. However, the maximum stresses on the cage and the upper endplate of the ATPRS model were generally higher. Conclusion: Although the novel ATPRS intervertebral fusion system generally had greater endplate stress than ACLP and ATPS, it can better stabilize cervical three-column injuries and might reduce the occurrence of adjacent segment degeneration (ASD). Furthermore, further studies and improvements are necessary for the ATPRS intervertebral fusion system.

P21. Comparison of patient-reported postoperative dysphagia in patients undergoing one-level versus two-level anterior cervical discectomy and fusion with the Zero-P Implant System

P21. Comparison of patient-reported postoperative dysphagia in patients undergoing one-level versus two-level anterior cervical discectomy and fusion with the Zero-P Implant System

The Effect of Preoperative Exposure to Benzodiazepines on Opioid Consumption After One and Two-level Anterior Cervical Discectomy and Fusion.

Retrospective cohort. Investigate the relationship between preoperative benzodiazepine exposure and postoperative opioid use in patients undergoing primary 1 or 2-level anterior cervical discectomy and fusion (ACDF). Little is known about the effect of preoperative benzodiazepine exposure on postoperative opioid use in spine surgery. Patients undergoing primary 1 or 2-level ACDF at a single institution from February 2020 to November 2021 were identified through electronic medical records. The prescription drug monitoring program was utilized to record the name, dosage, and quantity of preoperative benzodiazepines/opioids filled within 60 days before surgery and postoperative opioids 6 months after surgery. Patients were classified as benzodiazepine naïve or exposed according to preoperative usage, and postoperative opioid dose and duration were compared between groups. Regression analysis was performed for outcomes that demonstrated statistical significance, adjusting for preoperative opioid use, age, sex, and body mass index. Sixty-seven patients comprised the benzodiazepine-exposed group whereas 90 comprised the benzodiazepine-naïve group. There was no significant difference in average daily morphine milligram equivalents between groups (median: 96.0 vs 65.0, P = 0.11). The benzodiazepine-exposed group received postoperative opioids for a longer duration (median: 32.0 d vs 12.0 d, P = 0.004) with more prescriptions (median: 2.0 vs 1.0, P = 0.004) and a greater number of pills (median: 110.0 vs 59.0, P = 0.007). On regression analysis, preoperative benzodiazepine use was not significantly associated with postoperative opioid duration [incidence rate ratio (IRR): 0.93, P = 0.74], number of prescriptions (IRR: 1.21, P = 0.16), or number of pills (IRR: 0.89, P = 0.58). While preoperative benzodiazepine users undergoing primary 1 or 2-level ACDF received postoperative opioids for a longer duration compared with a benzodiazepine naïve cohort, preoperative benzodiazepine use did not independently contribute to this observation. These findings provide insight into the relationship between preoperative benzodiazepine use and postoperative opioid consumption. Level III.

The Effects of the Use of Single-Screw Plates (Univertebral Screw Plates) versus Double-Screw Plates (Bivertebral Screw Plates) on Fusion After One-Level or Two-Level Anterior Cervical Discectomy and Fusion

In this study, we aimed to retrospectively analyze the effects of the use of univertebral screw plates (USPs) and bivertebral screw plates (BSPs) on fusion in patients who underwent anterior cervical discectomy and fusion (ACDF). Forty-two patients who were treated with USPs or BSPs after 1-level or 2-level ACDF and had a minimum follow-up period of 2 years were included in the study. Fusion and the global cervical lordosis angle were evaluated using direct radiographs and computed tomography images of the patients. The clinical outcomes were assessed using the Neck Disability Index and visual analog scale. Seventeen patients were treated using USPs and 25 patients using BSPs. Fusion was achieved in all patients who underwent BSP fixation (1-level ACDF, 15 patients; 2-level ACDF, 10 patients) and 16 of the 17 patients who underwent USP fixation (1-level ACDF, 11 patients; 2-level ACDF, 6 patients). The plate of the patient with fixation failure had to be removed because it was symptomatic. A statistically significant improvement was observed in the immediate postoperative period and at the last follow-up in terms of global cervical lordosis angle, visual analog scale score, and Neck Disability Index ofallpatients who underwent 1-level or 2-level ACDF surgery (P < 0.05) CONCLUSIONS: Although USPs are less costly and easier to implant, the effect of USPs and BSPs on fusion and clinical outcomes is similar. Thus, surgeons may prefer to use USPs after 1-level or 2-level ACDF.

Biomechanical effect of endplate defects on the intermediate vertebral bone in consecutive two-level anterior cervical discectomy and fusion: a finite element analysis

BackgroundIntermediate vertebral collapse is a newly discovered complication of consecutive two-level anterior cervical discectomy and fusion (ACDF). There have been no analytical studies related to the effects of endplate defects on the biomechanics of the intermediate vertebral bone after ACDF. This study aimed to compare the effects of endplate defects on the intermediate vertebral bone biomechanics in the zero-profile (ZP) and cage-and-plate (CP) methods of consecutive 2-level ACDF and to determine whether collapse of the intermediate vertebra is more likely to occur using ZP.MethodsA three-dimensional finite element (FE) model of the intact cervical spine (C2–T1) was constructed and validated. The intact FE model was then modified to build ACDF models and imitate the situation of endplate injury, establishing two groups of models (ZP, IM-ZP and CP, IM-ZP). We simulated cervical motion, such as flexion, extension, lateral bending and axial rotation, and compared the range of motion (ROM), upper and lower endplate stress, fusion fixation device stress, C5 vertebral body stress, intervertebral disc internal pressure (intradiscal pressure, or IDP) and the ROM of adjacent segments in the models.ResultsThere was no significant difference between the IM-CP model and the CP model in the ROM of the surgical segment, upper and lower endplate stress, fusion fixation device stress, C5 vertebral body stress, IDP, or ROM of the adjacent segments. Compared with the CP model, the endplate stress of the ZP model is significantly higher in the flexion, extension, lateral bending and axial rotation conditions. Compared with the ZP model, endplate stress, screw stress, C5 vertebral stress and IDP in IM-ZP were significantly increased under flexion, extension, lateral bending and axial rotation conditions.ConclusionsCompared to consecutive 2-level ACDF using CP, collapse of the intermediate vertebra is more likely to occur using ZP due to its mechanical characteristics. Intraoperative endplate defects of the anterior lower margin of the middle vertebra are a risk factor leading to collapse of the middle vertebra after consecutive 2-level ACDF using ZP.

Management of dynamic cervical kyphosis with dorsal epidural lipomatosis: a Hirayama disease variant? Illustrative case.

Hirayama disease, a cervical myelopathy characterized most commonly by a self-limiting atrophic weakness of the upper extremities, is a rare entity, scarcely reported in the literature. Diagnosis is made by spinal magnetic resonance imaging (MRI), which typically shows loss of normal cervical lordosis, anterior displacement of the cord during flexion, and a large epidural cervical fat pad. Treatment options include observation or cervical immobilization by collar or surgical decompression and fusion. Here, the authors report an unusual case of a Hirayama-like disease in a young White male athlete who presented with rapidly progressive paresthesia in all 4 extremities and no weakness. Imaging showed characteristic findings of Hirayama disease as well as worsened cervical kyphosis and spinal cord compression in cervical neck extension, which has not previously been reported. Two-level anterior cervical discectomy and fusion and posterior spinal fusion improved both cervical kyphosis on extension and symptoms. Given the disease's self-limiting nature, and a lack of current reporting, there remains no consensus on how to manage these patients. Such findings presented here demonstrate the potentially heterogeneous MRI findings that can be observed in Hirayama disease and emphasize the utility of aggressive surgical management in young, active patients whereby a cervical collar may not be tolerated.

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.

No Difference in Two-Year Revisions Between Hybrid Fusion and Two-Level Anterior Discectomy and Fusion: A National Database Study.

Retrospective Cohort. This study utilized a large national database to compare two-year revision rates, in addition to complications and costs, of hybrid surgery (HS) compared to two-level anterior cervical discectomy and fusion (ACDF). This study used the PearlDiver Mariner dataset selecting for patients aged 18 and older who had at least 90-day active longitudinal follow-up who underwent two-level ACDF or two-level Hybrid surgery (single level ACDF and single level CDA). Patients with prior spinal trauma, infection, cancer, or posterior fusion were excluded. Primary outcomes measures were 90-day major and minor medical complications, ED visits, readmissions, as well as two-year revisions. Patients were also assessed for postoperative dysphagia, incidental durotomy, vascular injury, 90-day surgical site, and implant complications. Additionally, hospitalization and postoperative costs were evaluated. There were 4570 two-level ACDF surgeries and 888 hybrid surgeries. After matching the cohorts, no statistical differences in demographics were found. There were no differences in reoperation rates at all measured time points nor 2-year complications. HS had a lower incidence of major (1.6% vs 3.1%, P = .003) and minor complications (3.0% vs 4.6%, P = .009) than ACDF. 90-day readmission was lower in the HS cohort (2.8% vs 4.2%), P = .024. HS was associated with reduced hospitalization costs -$2614 (-$3916 to -$904, P < .001). 3516 patients had ACDF, and 699 had HS with at least 2years of follow-up. Hybrid surgery is a safe and effective surgical treatment for cervical disease in appropriately selected patients.

Soft Cervical Orthosis Use Does Not Improve Fusion Rates After One-Level and Two-Level Anterior Cervical Discectomy and Fusion

To determine if postoperative soft cervical orthosis use affects arthrodesis rates on a per-level or construct basis after 1-level and 2-level anterior cervical discectomy and fusion (ACDF). Electronic medical records were queried for 1-level and 2-level primary ACDF between 2016 and 2019 at a single academic center. Surgeons prescribed either a soft cervical orthosis or no orthosis. Pseudarthrosis rates were evaluated by dynamic cervical spine radiographs with arthrodesis defined by <1 mm of interspinous motion. Continuous and categorical data were compared using analysis of variance or χ2 tests. Multivariate logistic regression analysis was used to examine independent predictors of pseudarthrosis. A total of 316 unique patients (504 instrumented levels) met the inclusion criteria. Eighty-four percent of patients were prescribed a soft cervical orthosis. Overall, arthrodesis occurred at 344 (80.9%) and 62 (78%) levels in patients with and without cervical orthosis, respectively. When evaluating patients placed in a cervical orthosis versus those who were not, there were no differences in pseudarthrosis or revision rates. Further, there were no differences in pseudarthrosis on a per-level basis. Further, cervical orthosis use was not an independent predictor of pseudarthrosis (odds ratio, 0.86; 95% confidence interval, 0.47-1.57; P=0.623) on multivariate analysis. Postoperative placement of soft cervical orthoses after 1-level or 2-level ACDF was not associated with improved arthrodesis or reduced rate of revision surgery.

Cervical disc arthroplasty combined with two-level ACDF for the treatment of contiguous three-level cervical degenerative disc disease: A comparative study.

To compare the differences among constructs with one-level cervical disc arthroplasty (CDA) and two-level anterior cervical discectomy and fusion (ACDF).A retrospective study was conducted involving patients who underwent one-level CDA and two-level ACDF between June 2012 and July 2020. According to the different locations of CDA and ACDF, we divided the constructs into three types: type Ⅰa: CDA-ACDF-ACDF; type Ⅰb: ACDF-CDA-ACDF; type Ⅰc: ACDF-ACDF-CDA. The differences of clinical and radiological outcomes were evaluated.Fifty-three patients were included with 29 in type Ⅰa group, 11 in type Ⅰb group, and 13 in type Ⅰc group. After surgery, all groups showed significant improvement in apanese Orthopedic Association, Neck Disability Index, and Visual Analog Scale scores (p < 0.001). Range of motion(ROM) of the total cervical spine in type Ⅰc group decreased significantly compared with those in type Ⅰa and type Ⅰb groups (p < 0.05). No significant differences in ROM of the arthroplasty segment and the variations in ROM of the superior adjacent segment were observed among thethree groups. The fusion rates of the superior ACDF segments were significantly higher at 6 and 12 months postoperatively than those of the inferior ACDF segments (p < 0.05).The clinical outcomes were similar among constructs concerning different locations of CDA and ACDF in three-level hybrid surgery. ROM of the cervical spine in type Ⅰc group decreased significantly compared with that in type Ⅰa and type Ⅰb groups. The fusion rates of superior ACDF segments were higher at early time points after surgery than those of inferior ACDF segments.

Return-to-Work Status Following One- and Two-Level Anterior Cervical Discectomy and Fusions: A Prospective Cohort Study.

Background: The purpose of this article was to determine the rate of return to work (RTW) and contributing factors after a one- and two-level anterior cervical discectomy and fusion (ACDF), a common spine surgery. Recognizing the contributing factors to RTW of occupationally active patients is important.Methodology: In this study, 68 patients were examined at three, six, and nine months after ACDF by the same team and same spinal surgeon at a single medical center, and the rate of RTW and contributing factors were determined. In this study, relationships were analyzed by the logistic regression method.Results: The results of this study demonstrated that 77.9%, 82.4%, and 82.4% of workers had returned to work after three, six, and nine months, respectively. At nine months, 82.4% of the patients had returned to work, 19.6% returned to part-time work, and 80.4% had returned to their previous work. Conversely, 17.6% of the patients had not returned to work after nine months. In the logistic regression analysis, older age, longer absence from work before surgery, and less employer support were the related factors for no RTW.Conclusions: Per the results, it may be concluded that nearly 82% of patients with ACDF had returned to work after nine months of follow-up. Lack of RTW is affected by older age, longer absence from work before surgery, and employer support. Planning according to these variables can reduce the burden of the problem.

Over-correction of curvature causes the non-surgical curvature loss in one- and two-level anterior cervical discectomy and fusion.

Over-correction of curvature causes the non-surgical curvature loss in one- and two-level anterior cervical discectomy and fusion.

Finite Element Analysis of the Effect of Dynamic Plating on Two-Level Anterior Cervical Discectomy Fusion Biomechanics

The limitations of anterior cervical discectomy and fusion (ACDF) are related to mechanical failure of the construct after recurring subsidence and migration. In the present study, we evaluated the effect of the maximum rotation of variable angle screws on the range of motion (ROM), cage migration, and subsidence. Five finite element models were developed from a C2-C7 cervical spine model. The first model was an intact C2-C7 spine model, and the second model was an altered C2-C7 model with C4-C6 cage insertion and a 2-level static plate. The other three models were altered C2-C7 models with the same C4-C6 cage insertion and a 2-level dynamic plate. The ROM of C4-C6 in the static plate model was reduced by ∼14° from the intact model but only reduced by ∼9° in the dynamic plate models. The maximum migration and subsidence at the cage-endplate interface in the dynamic plate models were lower than those in the static plate model for all moments. The von Mises stress of the C3-C4 and C6-C7 discs in the dynamic plate models was lower than that in the static plate model. Our results indicate that dynamic plating has promising potential (greater ROM and lower von Mises stress of discs) for stabilization in multilevel anterior cervical discectomy and fusion than static plating, although both dynamic and static plates showed lower ROM than the intact model. A lower screw rotational angle resulted in superior biomechanical performance (lower incidence of migration and subsidence) compared with a higher rotational angle in multilevel applications, regardless of loading.

Comparison of outcomes and complications between one- and two-level anterior cervical discectomy and fusion: a population-based study of 410 patients

Objective The objective of this study was to compare outcomes and patient satisfaction, and secondly to compare complication rates between one- and two-level anterior cervical discectomy and fusion (ACDF) for cervical radiculopathy. Methods Data from patients receiving one- or two-level ACDF for cervical radiculopathy at two institutions were prospectively collected and retrospectively analysed. Patients were separated into one-level ACDF and two-level ACDF. Comparison analyses of patient-reported outcome measures (PROMs) comprising Visual Analogue Scale for neck pain (VAS-NP) and arm pain (VAS-AP), Neck Disability Index (NDI), and EQ-5D 3-level version (EQ-5D-3L) were performed between baseline and 1-year follow-up and between groups as well as achievement of minimal clinically important differences (MCID) in PROMs and satisfaction. Additionally, complications were compared between groups. Results A total of 410 patients (270 one-level and 140 two-level) were included. PROMs improved significantly from baseline to 1-year follow-up (p < 0.001) in both groups. When comparing PROMs between one- and two-level ACDF, a trend towards greater improvement was observed in patients undergoing one-level ACDF, notably in EQ-5D-3L (p = 0.073). Significantly more patients in the one-level group achieved MCID in VAS-NP compared to patients in the two-level group (56% vs 44%, p = 0.025). Two hundred and ninety-six (67%) patients reported to be satisfied, but the one-level group trended to be more satisfied (70% vs. 62%). One-level ACDF further demonstrated a trend of more favourable complication profiles; however, complication rates were low in both groups. The risk of intraoperative complications was 2.4%, postoperative complications in-hospital were 1.2%, and patient-reported postoperative events post-discharge 42%. Conclusions One- and two-level ACDF are effective procedures for degenerative cervical nerve root compression. Yet, significantly more patients in the one-level group achieved MCID in neck pain compared to patients in the two-level group.

Two-Level Anterior Cervical Discectomy and Fusion versus Hybrid Total Disc Replacement for Bilevel Pathology with Cervical Radiculopathy/Myelopathy: A Comparative Study with a Minimum 2-Year Follow-up in an Indian Population.

Study DesignRetrospective study.PurposeTo study the outcomes of two-level anterior cervical discectomy and fusion (2L-ACDF) versus hybrid total disc replacement (H-TDR) for cervical myeloradiculopathy.Overview of LiteratureFor bilevel disc issues of the cervical spine, 2L-ACDF has been a historical tool with numerous implants used at different time frames. Recent developments in total disc replacement at mobile level with fusion at a spondylotic level known as hybrid fixation have added a new armamentarium for such disorders.MethodsAn analysis of 49 consecutive patients who underwent 2L-ACDF (n=22) and H-TDR (n=27) from January 1, 2014 to December 31, 2017 was performed. Data were studied as retrieved from InstaPACS ver. 4.0 (Mediff Technologies Pvt. Ltd., Bengaluru, India) and medical records.ResultsTwenty-two patients with 2L-ACDF and 27 patients with H-TDR were included. The mean±standard deviation (SD) follow-up duration was 4.0±1.5 years in H-TDR and 3.1±1.1 years in 2L-ACDF. The mean±SD Neck Disability Index (NDI) decreased from 26.1±7.6 to 6.5±3.9 in the H-TDR group and from 27.6±7.2 to 6.4±4.8 in the 2L-ACDF group at final follow-up. Disc height at suprajacent level in the 2L-ACDF group was 4.12±0.48 mm, 4.10±0.45 mm, and 4.05±0.48 mm preoperatively, at 1-year, and final follow-up, respectively. Disc height at supradjacent level in the H-TDR group was 4.28±0.36 mm, 4.20±0.32 mm, and 4.19±0.34 mm preoperatively, at 1-year, and final follow-up, respectively.ConclusionsThere was significantly improved NDI in both groups. Adjacent segment disc height loss was greater in the 2L-ACDF group than in H-TDR but not statistically significant (p=0.304). Supradjacent segment range of motion was greater in the 2L-ACDF group than in the H-TDR group (p=0.003). Both findings supported radiographic adjacent segment degeneration (ASD), but symptomatic ASD was absent in both groups.

Analyzing the Significance of T1 Slope minus Cervical Lordosis in Patients with Anterior Cervical Discectomy and Fusion Surgery.

ObjectiveAccurate measurement of T1 slope (a component of T1s minus cervical lordosis [CL]) is often constrained by anatomical limitations. In this situation, efforts should be made to find the exact meaning of T1s-CL and whether there are any alternatives to it. MethodsWe enrolled 117 patients who received two-level anterior cervical discectomy and fusion (ACDF). Occipital slope, C2 slope (C2s), C7 slope (C7s), T1, O-C2 angle (O-C2A), C2-7 angle (C2-7A), O-C7 angle (O-C7A), T1s-CL, C7-T1 angle (C7-T1A), and C2-7 sagittal vertical axis were measured. We determined 16° (T1s-CL) as the reference point for dividing subjects into the mismatch group and the balance group, and a comparative analysis was performed. ResultsThe mean value of C7-T1A was constantly maintained within 2.6° peri-operatively. In addition, C2s and T1s-CL showed the same absolute change (Δ|0.8|°). The mean values of T1s-CL of the mismatch and balance groups were 23.0° and 7.6°, respectively. The five factors with the largest differences between the two groups were as follows : C2s (Δ13.3°), T1s-CL (Δ15.4°), O-C2A (Δ8.7°), C2-7A (Δ14.7°), and segmental angle (Δ7.9°) before surgery. Only four factors showed statistically significant change between the two groups after ACDF : T1s-CL (Δ4.0° vs. Δ0.2°), C2s (Δ3.2° vs. Δ0.7°), O-C2A (Δ2.6° vs. Δ1.3°), C2-7A (Δ6.3° vs. Δ1.3°). A very strong correlation between T1s-CL and C2s was also found (r=|0.88–0.96|). ConclusionC2s itself may be the essential key to represent T1s-CL. The amounts and directions of change of these two factors (T1s-CL and C2s) were also almost identical. The above phenomenon was re-confirmed once again through the correlation analysis.

Evaluation of changes in cervical sagittal balance and clinical parameters in patients undergoing two-level anterior cervical discectomy and fusion.

Anterior cervical discectomy and fusion (ACDF) is an effective method in treating cervical sagittal imbalance and spine deformations. The aim of this work was to assess whether changes of the Cobb angle, sagittal vertical axis (SVA) and T1 slope parameters affect the outcomes of surgical treatment. A prospective study was performed in 30 patients qualified for surgical treatment for cervical degenerative disc disease. The ACDF was performed on 2 levels. Every patient underwent an X-ray examination before surgery and 3 months after the procedure. The following parameters were assessed: the T1 slope, the angle of cervical lordosis, the SVA distance, quality of life assessed using the Neck Disability Index (NDI), and perceived pain measurement assessed using the Visual Analogue Scale (VAS). The cervical lordosis angle significantly changed (p < 0.01) to an average of 11.52°. The SVA C2-C7 distance significantly decreased (p < 0.001) to an average of 21.06 mm. The value of the T1 slope angle did not change significantly before and after surgery (p = 0.706). After surgery, statistically significant improvement was achieved on the NDI scale for neck pain (p < 0.001) to an average of 9. The NDI score significantly decreased over time (p < 0.001), and this change was significantly related to the increased Cobb angle (p = 0.036). Improvement in cervical lordosis C2-C7 can improve the outcomes of surgical treatment. Preoperative analysis of X-rays and sagittal balance parameters may be beneficial for treatment outcomes.

Is the fusion order of the cranial and caudal levels different in two-level anterior cervical discectomy and fusion for cervical spondylopathy? A retrospective study

Study designRetrospective study.ObjectiveThis study aimed to compare the fusion order between the cranial and caudal levels in two-level anterior cervical discectomy and fusion (ACDF) with a zero-profile device in the treatment of cervical spondylopathy.Summary of background dataFusion is the standard used to judge the success of ACDF. However, the fusion order in two-level ACDF remains uncertain. The mechanical environment of different levels is different, which may affect the fusion rate or fusion order.MethodsFrom 2014 to January 2019, data of consecutive patients with two-level cervical disk degenerative disease who underwent ACDF were retrospectively reviewed. Radiological assessments were based on the range of motion of the fusion level, segment slope, and disk height, and complications were assessed. Data were analyzed using the paired t, Mann-Whitney U, χ2, Fisher exact, and rank-sum tests and logistic regression analysis.ResultsIn total, 118 patients were ultimately enrolled for analysis in the study. The respective fusion rates of the cranial and caudal levels were 26.27% and 10.17% (p < 0.05) at 3 months, 58.47% and 42.37% (p < 0.05) at 6 months, 86.44% and 82.20% (1 0.05) at 1 year, and 92.37% and 89.83% (p > 0.05) at the last follow-up. Multivariate logistic regression analysis indicated that the preoperative segmental slope and cranial level were independent risk factors for non-fusion. The adjacent segment degeneration (ASD) and subsidence rates were comparable between the two levels.ConclusionThe caudal level had a slower fusion process than the cranial level. A higher preoperative segment slope was a risk factor for fusion. However, the subsidence and ASD rate were comparable between the caudal and cranial levels in the two-level ACDF.