After Anterior Cervical Discectomy And Fusion Research Articles

Cervical Disc Arthroplasty for the Treatment of Adjacent Segment Disease after Anterior Cervical Discectomy and Fusion

Study Design. A retrospective chart review was conducted at a single institution. Objective. The purpose of this study was to investigate clinical outcomes of cervical disc arthroplasty (CDA) used for the treatment of symptomatic adjacent segment disease (ASD) developed after anterior cervical discectomy and fusion (ACDF). Summary of Background Data. A major clinical concern following ACDF is the development of ASD. ASD after ACDF is often treated with an additional fusion, but risks include pseudoarthrosis and further ASD. CDA is a motion preserving alternative that addresses these concerns, and therefore, has been proposed as an alternative treatment for ASD after ACDF. Methods. CDA patients with prior adjacent-level ACDF (n=120) were identified from a consecutive series of CDA patients at one institution. Pre- to post- CDA patient-reported outcome measures were compared using the paired Wilcoxon signed-rank test. Results. A total of 142 devices were implanted – 98 patients underwent a one-level CDA, and 22 patients underwent two-level CDA. The mean follow-up duration after CDA was 32.11 months. Neck pain, arm pain, and Neck Disability Index (NDI) scores significantly improved from the preoperative to postoperative timepoint (respectively: 6.14 to 3.02, 4.42 to 1.61, 44.28 to 28.62, all P<0.001). In total, 7 patients underwent reoperation (5.83%). One of these patients underwent reoperation for pseudarthrosis at the level of ACDF following a hybrid procedure. The indications for index level reoperations (n=3) were foraminal stenosis, osteolysis, and postoperative hematoma. All patients with an adjacent level reoperation (n=3) received surgery at levels adjacent to the prior fusion, not the more recent CDA. Conclusion. The results of this study found CDA was effective for the treatment of ASD following ACDF. CDA appears to be a viable treatment option for ASD after ACDF in appropriately selected patients.

Novel Risk Factors for Postoperative Hematoma Requiring Reoperation Following Anterior Cervical Discectomy and Fusion.

Retrospective cohort study. To investigate the correlation between comorbid chronic obstructive pulmonary disease (COPD), asthma, tobacco use, and the incidence of postoperative hematoma requiring reoperation after anterior cervical discectomy and fusion (ACDF). Prior studies have identified general risk factors such as multilevel fusion and coagulopathy. However, specific coughing-related factors like COPD, asthma, and tobacco use have not been extensively investigated. Patients who underwent single or multilevel ACDF between 2011 and 2021 were identified using Current Procedural Terminology (CPT) codes in the PearlDiver database. The primary outcome was the occurrence of postoperative hematoma requiring reoperation within 30 days. χ2 tests and t tests compared groups, and multivariable logistic regression identified predictors for postoperative hematoma. Among 399,900 patients with ACDF, 901 (0.2%) developed postoperative hematoma requiring reoperation within 30 days. Patients with postoperative hematoma were older (58 vs. 55, P<0.001) and predominantly male (62.5% vs. 44.9%, P<0.001). After adjustment, tobacco use and comorbid COPD were associated with postoperative hematoma (odds ratio [OR], 1.27; 95% confidence interval [CI], 1.10-1.47; P<0.001 and OR, 1.41; 95% CI, 1.21-1.64; P<0.001, respectively). Comorbid asthma was not a significant risk factor. Additional risk factors included comorbid hypertension (OR, 1.46; 95% CI, 1.18-1.82; P<0.001), coagulopathy (OR, 1.50; 95% CI, 1.24-1.81; P<0.001), anemia (OR, 1.38; 95% CI, 1.17-1.62; P<0.05), and history of deep vein thrombosis (OR, 1.93; 95% CI, 1.44-2.54; P<0.001). Tobacco use and COPD were identified as novel risk factors for postoperative hematoma formation requiring reoperation after ACDF. Recognizing these modifiable factors, providers may consider postponing nonemergent ACDFs until patients undergo smoking cessation programs or receive optimal COPD management.

Osteoporosis is not associated with reoperation or pseudarthrosis after anterior cervical discectomy and fusion through 4-years’ follow-up: a retrospective cohort study of US academic health centers

BACKGROUND CONTEXTOsteoporosis has been proposed as a risk factor for reoperation after anterior cervical discectomy and fusion (ACDF), yet this potential association has been understudied, with conflicting results to date. PURPOSEThis study examines the hypothesis that adults with osteoporosis would have an increased risk of reoperation after ACDF compared to matched adults without osteoporosis. STUDY DESIGN/SETTINGRetrospective cohort study. PATIENT SAMPLETwo matched cohorts (mean age: 62 years; 75% female), each with 1,019 patients, who underwent primary ACDF. Cohorts were determined by the presence or absence of a diagnosis of osteoporosis. OUTCOME MEASURESIncidence of reoperation occurring over 4 years postoperatively, with our primary outcome being the risk ratio (RR) of reoperation with 95% confidence intervals (CI). Secondary outcomes included risk and mean count of oral opioid prescriptions and risk of pseudoarthrosis. METHODSWe utilized the TriNetX network to identify adults undergoing their first ACDF from 2004 to 2020, excluding those with serious pathology, and divided patients into 2 cohorts: osteoporosis and nonosteoporosis. Patients were propensity matched according to key risk factors for reoperation. RESULTSPatients with osteoporosis had no statistically significant or meaningful difference in risk of reoperation compared to nonosteoporotic patients over 4-years’ follow-up [95% CI] (17.3% vs. 16.5%; RR: 1.05 [0.86, 1.27]; p=.6361). Similarly, there were no significant differences in the risk of pseudoarthrosis (26.5% vs. 29.1%; RR: 0.91 [0.79, 1.05]; p=.1820), oral opioid prescription (75.0% vs. 76.0%; RR: 0.99 [0.94, 1.04]; p=.6067), or mean oral opioid prescription count (11.5 vs. 11.8; p=.7040). CONCLUSIONCompared to matched nonosteoporosis controls, osteoporosis was not associated with a statistically significant or clinically meaningful increase in risk of reoperation in adults over 4 years after ACDF. Furthermore, osteoporosis was not associated with a significant or meaningful risk of pseudoarthrosis or oral opioid prescription after ACDF, although more research is needed for corroboration. Additional research is needed to clarify whether those with osteoporosis have meaningful differences in pain and function compared to those without osteoporosis following ACDF.

Surgery on the C3-4 Level and the Presence of Ligamentum Flavum Hypertrophy Increases the Risk of 30-Day Reoperation Rate After Anterior Cervical Discectomy and Fusion

BACKGROUND AND OBJECTIVES: Cervical myelopathy caused by C3-4 level degeneration often exhibits different characteristics after anterior cervical discectomy and fusion (ACDF) than other cervical levels. This study compared the outcomes of C3-4 ACDF with surgeries at other levels and identified risk factors of 30-day reoperation after ACDF. METHODS: We retrospectively analyzed patients who underwent ACDF for degenerative cervical disease from 2018 to 2023. The patients were divided into 2 groups based on the level of surgery: C3-4 and non–C3-4 groups. Radiological outcomes, including cervical alignment and range of motion (ROM), were analyzed. Clinical outcomes were assessed with patient-reported outcomes and the rates of 30-day reoperation and complications after ACDF. Patient-reported outcomes included visual analog scale for neck pain, visual analog scale for arm pain, and modified Japanese Orthopedic Association scores. Risk factors of 30-day reoperation were assessed. RESULTS: Of 259 patients, 74 (28.6%) and 185 (71.4%) were in the C3-4 and non–C3-4 groups, respectively. The C3-4 group exhibited lower C2-7 ROM (P = .019), higher C3-4 ROM (P = .015), and greater C3-4 %ROM (P = .014). The C3-4 group demonstrated lower preoperative and 1-month postoperative modified Japanese Orthopedic Association scores (P &lt; .001; P &lt; .001, respectively). The rate of 30-day reoperation was significantly higher in the C3-4 group (9.5%) compared with the non–C3-4 group (2.2%) (P = .014). In addition, C3-4 surgical level (odds ratio = 4.99, P = .034) and ligament flavum hypertrophy (odds ratio = 5.84, P = .018) were identified as independent risk factors of 30-day reoperation after ACDF. CONCLUSION: Surgery on C3-4 level showed a higher risk of 30-day reoperation than other levels. It is likely due to C3-4 surgical level, and ligament flavum hypertrophy contributes to cord compression, particularly in the unstable early postoperative period.

Which interbody device minimized nonunion, subsidence, and reoperation after anterior cervical discectomy and fusion? A systematic review and meta-analysis comparing allograft versus polyetheretherketone cage.

Nonunion and significant subsidence after anterior cervical discectomy and fusion (ACDF) are associated with poor clinical outcomes, which occasionally lead to revision surgery. Allograft and polyetheretherketone (PEEK) cages are the two most commonly used interbody spacer devices for ACDF. Although studies have been conducted to compare the efficacies of these two interbody materials, the question remains regarding the superiority of one over the other. Therefore, the authors conducted a systematic review and meta-analysis to compare nonunion, subsidence, and reoperation rates after ACDF using allograft and PEEK cages as interbody devices. In this systematic review and meta-analysis, the authors systematically searched the MEDLINE, EMBASE, and Cochrane Library databases for studies published prior to November 2023 that compared the efficacy and safety of allograft and PEEK cages for ACDF. A pooled analysis was designed to identify differences in nonunion, subsidence, and reoperation rates between the two interbody devices. Ten studies involving 1462 patients (allograft, 852 patients; PEEK cage, 610 patients) were included. The pooled analysis demonstrated that allograft had a significantly lower rate of nonunion compared to that of PEEK cages (OR 0.33, 95% CI 0.14-0.79; p = 0.01). Furthermore, the reoperation rate due to nonunion was significantly higher with PEEK cages compared to that with allograft (OR 0.28, 95% CI 0.11-0.71; p < 0.01), whereas the reoperation rate due to overall causes did not display significant results (OR 0.38, 95% CI 0.11-1.29; p = 0.12). The incidence of significant subsidence (OR 0.66, 95% CI 0.28-1.55; p = 0.34) and the mean amount of subsidence (standard mean difference 0.03, 95% CI -0.42 to 0.47; p = 0.90) did not demonstrate significant differences between allograft and PEEK cages. Overall, the current meta-analysis suggests the advantages of allograft over PEEK cages used for ACDF, due to an enhanced fusion rate and minimized revision risk, with no increase in the risk of subsidence.

A Comparison of Clinical Outcomes Between Anterior Cervical Discectomy and Fusion Versus Posterior Cervical Laminoplasty for Multilevel Cervical Myelopathy.

Retrospective Cohort. To compare patient-reported outcomes and surgical outcomes after anterior cervical discectomy and fusion (ACDF) versus cervical laminoplasty for multilevel cervical spondylotic myelopathy. Treatment options for multilevel cervical spondylotic myelopathy include ACDF and cervical laminoplasty. Given that the literature has been mixed regarding the optimal approach, especially in patients without kyphosis, there is a need for additional studies investigating outcomes between ACDF and cervical laminoplasty. A retrospective review was conducted of adult patients undergoing 3 or 4-level surgery. Patients with preoperative kyphosis based on C2-C7 Cobb angles were excluded. The electronic medical record and institutional databases were reviewed for baseline characteristics, surgical outcomes, and patient-reported outcomes. A total of 101 patients who underwent ACDF and 52 patients who underwent laminoplasty were included in the study. The laminoplasty cohort had a higher overall Charlson Comorbidity Index (3.10 ± 1.43 vs 2.39 ± 1.57, P = 0.011). Both groups had a comparable number of levels decompressed, C2-C7 lordosis, and diagnosis of myelopathy versus myeloradiculopathy. Patients who underwent laminoplasty had a longer length of stay (2.04 ± 1.15 vs 1.48 ± 0.70, P = 0.003) but readmission, complication, and revision rates were similar. Both groups had similar improvement in myelopathy scores (∆modified Japanese Orthopedic Association: 1.11 ± 3.09 vs 1.06 ± 3.37, P = 0.639). ACDF had greater improvement in Neck Disability Index (∆Neck Disability Index: -11.66 ± 19.2 vs -1.13 ± 11.2, P < 0.001), neck pain (∆Visual Analog Scale-neck: -2.69 ± 2.78 vs -0.83 ± 2.55, P = 0.003), and arm pain (∆Visual Analog Scale-arm: -2.47 ± 3.15 vs -0.48 ± 3.19, P = 0.010). These findings persisted in multivariate analysis except for Neck Disability Index. ACDF and cervical laminoplasty appear equally efficacious at halting myelopathic progression. However, patients who underwent ACDF had greater improvements in arm pain at 1 year postoperatively. Longitudinal studies evaluating the efficacy of laminoplasty to mitigate adjacent segment disease are indicated to establish a robust risk-benefit assessment for these 2 procedures. III.

Correlation between axial symptoms and cervical sagittal alignment parameters in patients with two-level or three-level cervical spondylotic myelopathy: anterior cervcial discectomy and fusion versus hybird surgery.

To comparatively analyze the correlation between axial symptoms (AS) and cervical sagittal alignment parameters after anterior cervical discectomy and fusion (ACDF) and hybrid surgery (HS). From January 2018 to June 2023, 74 patients who underwent ACDF (n = 36) or HS (n = 38) for two-level or three-level cervical spondylotic myelopathy were retrospectively analyzed. The Visual Analogue Scale (VAS), Japanese Orthopedic Association (JOA), Neck Disability Index (NDI) were recorded to assess clinical outcomes. Cervical sagittal alignment parameters (Cobb's angle C2-7, C7 slope [C7S], and C2-7 sagittal vertical axis [C2-7 SVA]) were measured preoperatively, 3days postoperatively, and at the last follow-up. The range of motion (ROM) of C2-7 and ROM of surgical segment were measured. The occurrence of AS was observed at the last follow-up. Logistic regression was used to analyze the correlation between postoperative AS and cervical sagittal alignment parameters. Both in ACDF group and HS group, VAS, JOA and NDI scores showed significant improvements at 3-day postoperation and at the last follow-up (P < 0.05). However, there was no significant difference between the two groups (P > 0.05). The Cobb's angle C2-7 and C7S were significantly increased at 3days postoperation compared with pre-operatively in both groups (P < 0.05). C2-7SVA was increased in both groups 3days after surgery compared with pre-operatively, but there was no significant difference (P > 0.05). At the last follow-up, the ROM of C2-7 in ACDF group was significantly smaller than HS group (P < 0.05). The prevalence of postoperative AS in the ACDF group and HS group was 41.7 and 18.4%, respectively, with statistical difference between the two groups (P < 0.05). When simple Logistic regression analysis was used, the last Cobb's angle C2-7 (β = -0.088), the last C2-7SVA (β = 0.099) in ACDF group and the last C2-7SVA (β = 0.222) in HS group were all correlated with the occurrence of postoperative AS. When multiple Logistic regression analysis was used, only the last C2-7SVA (β = 0.181) in the HS group was positively correlated with the occurrence of postoperative AS. Both ACDF and HS can achieve satisfied clinical outcomes. ACDF and HS can improve cervical sagittal balance to a certain extent, and HS is superior to ACDF in maintaining ROM. The decrease of the last Cobb's angle C2-7 and the increase of the last C2-7SVA may be related to the occurrence of AS after ACDF. The increase of the last C2-7SVA was an independent risk factor for the occurrence of AS after HS.

Importance of the cervical paraspinal muscles in postoperative patient-reported outcomes and maintenance of sagittal alignment after anterior cervical discectomy and fusion.

The aim of this study was to investigate the influence of preoperatively assessed paraspinal muscle parameters on postoperative patient-reported outcomes and maintenance of cervical sagittal alignment after anterior cervical discectomy and fusion (ACDF). Patients with preoperative and postoperative standing cervical spine lateral radiographs and preoperative cervical MRI who underwent an ACDF between 2015 and 2018 were reviewed. Muscles from C3 to C7 were segmented into 4 functional groups: anterior, posteromedial, posterolateral, and sternocleidomastoid. The functional cross-sectional area and also the percent fat infiltration (FI) were calculated for all groups. Radiographic alignment parameters collected preoperatively and postoperatively included C2-7 lordosis and C2-7 sagittal vertical axis (SVA). Neck Disability Index (NDI) scores were recorded preoperatively and at 2 and 4-6 months postoperatively. To investigate the relationship between muscle parameters and postoperative changes in sagittal alignment, multivariable linear mixed models were used. Multivariable linear regression models were used to analyze the correlations between the changes in NDI scores and the muscles' FI. A total of 168 patients with NDI and 157 patients with sagittal alignment measurements with a median follow-up of 364 days were reviewed. The mixed models showed that a greater functional cross-sectional area of the posterolateral muscle group at each subaxial level and less FI at C4-6 were significantly associated with less progression of C2-7 SVA over time. Moreover, there was a significant correlation between greater FI of the posteromedial muscle group measured at the C7 level and less NDI improvement at 4-6 months after ACDF. The findings highlight the importance of preoperative assessment of the cervical paraspinal muscle morphology as a predictor for patient-reported outcomes and maintenance of C2-7 SVA after ACDF.

The Postoperative Airway Compromise Score—First Steps to Developing a Postoperative Tool for the Assessment of Upper Airway-Related Complications Following Anterior Cervical Spine Surgery

BackgroundAcute upper airway compromise is a rare but catastrophic complication after anterior cervical discectomy and fusion (ACDF). This study aims to develop a score to identify patients at risk for acute postoperative airway compromise (PAC). MethodsPotential risk factors for acute PAC were selected by a modified Delphi process. Ten patients with acute PAC were identified out of 1,466 patients who underwent elective ACDF between July 2014 - May 2019. A comparison group was created by a randomized selection process (non-PAC group). Associated factors with PAC and a p-value <.10 were entered into a logistic regression model and coefficients contributed each risk factor's overall score. Calibration of the model was evaluated by Hosmer-Lemeshow (H-L) goodness-of-fit test. Quantitative discrimination was calculated and the final model was internally validated with bootstrap sampling. ResultsWe identified 18 potential risk factors from our Delphi process, of which 6 factors demonstrated a significant association with airway compromise: age >65 years, current smoking status, ASA >2, history of a bleeding disorder, surgery of upper subaxial cervical spine (>C4), and duration of surgery >179 min. The final prediction model included five predictors with very strong performance characteristics. These five factors formed the PAC-Score (PACS) which had a range from 0 to 100. A score of 20 yielded the greatest balance of sensitivity (80%) and specificity (88%). ConclusionsThe acute Postoperative Airway Compromise Score (PACS) demonstrates strong performance characteristics. The PAC score may help identify patients at risk for upper airway compromise caused by surgical site abnormalities.

A novel MRI-based Cervical-Endplate Bone Quality score independently predicts cage subsidence after Anterior Cervical Discectomy and Fusion.

Postoperative cage subsidence after Anterior Cervical Discectomy and Fusion (ACDF) often has adverse clinical consequences and is closely related to Bone Mineral Density (BMD). Previous studies have shown that cage subsidence can be better predicted by measuring site-specific bone density. MRI-based Endplate Bone Quality (EBQ) scoring effectively predicts cage subsidence after lumbar interbody fusion. However, there is still a lack of studies on the practical application of EBQ scoring in the cervical spine. To create a similar MRI-based scoring system for Cervical-EBQ (C-EBQ) and to assess the correlation of the C-EBQ with endplate Computed Tomography (CT)-Hounsfield Units (HU) and the ability of this scoring system to independently predict cage subsidence after ACDF, comparing the predictive ability of the C-EBQ with the Cervical-Vertebral Bone Quality (C-VBQ) score. A total of 161 patients who underwent single-level ACDF for degenerative cervical spondylosis at our institution from 2012 to 2022 were included. Demographics, procedure-related data, and radiological data were collected, and Pearson correlation test was used to determine the correlation between C-EBQ and endplate HU values. Cage subsidence was defined as fusion segment height loss of ≥ 3mm. Receiver operating characteristic analysis and area-under-the-curve values were used to assess the predictive ability of C-EBQ and C-VBQ. A multivariate logistic regression model was developed to identify potential risk factors associated with subsidence. Cage subsidence was present in 65 (40.4%) of 161 patients. The mean C-EBQ score was 1.81 ± 0.35 in the group without subsidence and 2.59 ± 0.58 in the group with subsidence (P < 0.001). Multivariate analysis showed that a higher C-EBQ score was significantly associated with subsidence (OR = 5.700; 95%CI = 3.435-8.193; P<0.001), was the only independent predictor of cage subsidence after ACDF, had a predictive accuracy of 93.7%, which was superior to the C-VBQ score (89.2%), and was significantly negatively correlated with the endplate HU value (r = -0.58, P < 0.001). Higher C-EBQ scores were significantly associated with postoperative cage subsidence after ACDF. There was a significant negative correlation between C-EBQ and endplate HU values. The C-EBQ score may be a promising tool for assessing preoperative bone quality and postoperative cage subsidence and is superior to the C-VBQ.

Pack Years of Tobacco Cigarette Smoking as a Predictor of Bony Fusion after Anterior Cervical Discectomy and Fusion

Smoking tobacco cigarettes negatively impacts bone healing after spinal fusion. Smoking history is often assessed based on current smoker and nonsmoker status. However, in current research, smoking history has not been quantified in terms of pack years to estimate lifetime exposure and assess its effects. Our goal was to investigate the influence of smoking history, quantified in pack years, on bony fusion after anterior cervical discectomy and fusion (ACDF). A retrospective chart review of consecutive patients who underwent ACDF for cervical disc degeneration between September 21, 2017 and October 17, 2018 was conducted. Patient demographics, procedural variables, and postoperative outcomes were analyzed. Multivariate logistic regression analysis was performed to identify predictive factors for bony fusion following ACDF. Receiver operating characteristic curve analysis was used to determine the optimal discrimination threshold for smoking history pack years in association with nonfusion. Among 97 patients identified, 90 (93%) demonstrated bony fusion on postoperative imaging. Mean number of smoking history pack years was 6.1±13 for the fusion group and 16±21 for the nonfusion group. Multivariate logistic regression analysis suggested that increased pack years of tobacco cigarette smoking was a significant predictor of nonfusion (95% confidence interval, [1.0,1.1], P= 0.045). The receiver operating characteristic curve analysis revealed that 6.1 pack years best stratified the risk for nonfusion (area under the curve, 0.8). Patients with a history of tobacco cigarette smoking ≥6.1 pack years may have an increased risk of nonfusion after ACDF.

The association of cervical sagittal alignment with anterior bone loss following single-level anterior cervical surgery.

Anterior bone loss (ABL) is a common phenomenon after cervical disc replacement (CDR), which can also be observed after anterior cervical discectomy and fusion (ACDF). This study aimed to investigate the incidence and severity of ABL in single-level CDR and ACDF and explore the association of cervical sagittal alignment with ABL. This is a single-center retrospective cohort study. A total of 113 patients treated with CDR and 99 patients treated with ACDF were retrospectively reviewed from January 2014 to December 2018 in West China Hospital. Radiological data were collected at pre-operation, 1 week, 3 months postoperatively, and the last follow-up. The incidence and severity of ABL after both CDR and ACDF were evaluated. Cervical sagittal alignment parameters, including C0-C2 angle, cervical lordosis (CL), C2-C7 sagittal vertical axis (cSVA), T1 slope, functional spinal unit angle, disc angle, and surgical level slope, were evaluated. ABL was identified in 75 (66.4%) patients in the CDR group and 57 (57.6%) patients in the ACDF group. There were no significant differences in the incidence, severity, and location of ABL between the ACDF and CDR groups. For patients who underwent ACDF, the proportion of females was significantly higher in the ABL group (64.9% vs. 33.3%, P=0.002), whereas the body mass index (BMI) was significantly lower in the ABL group compared to the non-ABL group (22.72±3.09 vs. 24.60±3.04, P=0.002). No effect of ABL on the short-term clinical outcomes of ACDF and CDR was observed. In the ACDF group, patients with ABL had significantly smaller postoperative CL (11.83°±8.24° vs. 15.25°±8.32°, P=0.04) and cSVA (17.77±10.08 vs. 23.35±9.86 mm, P=0.007). In the CDR group, no significant differences were found in the cervical sagittal parameters between patients with and without ABL (CL: 12.58±8.70 vs. 15.46±8.50, P=0.10; cSVA: 20.95±8.54 vs. 19.40±9.43, P=0.38). ABL is common after both CDR and ACDF with comparable incidence and severity. Cervical sagittal alignment was closely related to ABL after ACDF yet had less influence on ABL after CDR.

Does Operative Level Impact Dysphagia Severity After Anterior Cervical Discectomy and Fusion?: A Multicenter Prospective Analysis.

Prospective multicenter cohort study. To explore the association between operative level and postoperative dysphagia after anterior cervical discectomy and fusion (ACDF). Dysphagia is common after ACDF and has several risk factors, including soft tissue edema. The degree of prevertebral soft tissue edema varies based on the operative cervical level. However, the operative level has not been evaluated as a source of postoperative dysphagia. Adult patients undergoing elective ACDF were prospectively enrolled at 3 academic centers. Dysphagia was assessed using the Bazaz Questionnaire, Dysphagia Short Questionnaire, and Eating Assessment Tool-10 (EAT-10) preoperatively and at 2, 6, 12, and 24 weeks postoperatively. Patients were grouped based on the inclusion of specific surgical levels in the fusion construct. Multivariable regression analyses were performed to evaluate the independent effects of the number of surgical levels and the inclusion of each particular level on dysphagia symptoms. A total of 130 patients were included. Overall, 24 (18.5%) patients had persistent postoperative dysphagia at 24 weeks and these patients were older, female, and less likely to drink alcohol. There was no difference in operative duration or dexamethasone administration. Patients with persistent dysphagia were significantly more likely to have C4-C5 included in the fusion construct (62.5% vs . 34.9%, P = 0.024) but there were no differences based on the inclusion of other levels. On multivariable regression, the inclusion of C3-C4 or C6-C7 was associated with more severe EAT-10 (β: 9.56, P = 0.016 and β: 8.15, P = 0.040) and Dysphagia Short Questionnaire (β: 4.44, P = 0.023 and (β: 4.27, P = 0.030) at 6 weeks. At 12 weeks, C3-C4 fusion was also independently associated with more severe dysphagia (EAT-10 β: 4.74, P = 0.024). The location of prevertebral soft tissue swelling may impact the duration and severity of patient-reported dysphagia outcomes at up to 24 weeks postoperatively. In particular, the inclusion of C3-C4 and C4-C5 into the fusion may be associated with dysphagia severity.

Interim Use of Antibiotic-Loaded Cement Spacer for Patients with Infected Cervical Fusion

The management of postoperative deep infection after anterior cervical discectomy and fusion (ACDF) remains challenging for spine surgeons. Our institution uses handmade antibiotic-loaded cement spacers to treat these complex cases. This study aimed to determine the efficacy and feasibility of this treatment. This study included 4 patients with deep cervical spine infections after ACDF who underwent our treatment between March 2012 and January 2022. Patients' laboratory data, visual analog scale scores, comorbidities, complications, and neurological status were recorded. Their clinical conditions were also evaluated based on the Neck Disability Index, Japanese Orthopaedic Association score, and Odom criteria. Infection eradication was achieved in all patients after treatment. The average preoperative visual analog scale score was 7.5 (range: 7-8); this decreased to 1.25 (range: 1-2) at 1year postoperatively. None of the patients experienced severe complications, such as neurological deterioration or bone graft dislodgement. The Neck Disability Index improved from a preoperative value of 54% (range: 48-60%) to 6% (range: 4-8%) at 1year postoperatively. The Japanese Orthopaedic Association score improved from a preoperative score of 10.25 (range: 10-11)-14.75 (range: 14-16) at 1year postoperatively. All patients achieved excellent outcomes based on Odom criteria at 1year postoperatively. Good clinical outcomes were achieved in this study. Although 2-stage surgery is required, this technique could be an alternative for patients with postoperative deep infection after ACDF.

Incidence of Adjacent Segment Degeneration and Its Associated Risk Factors Following Anterior Cervical Discectomy and Fusion: A Meta-Analysis

This study aimed to investigate the incidence of adjacent segment degeneration (ASD) and its associated risk factors in adults after anterior cervical discectomy and fusion (ACDF) surgery. An exhaustive search across multiple databases was conducted, including Embase, PubMed, Cochrane Library, and the Web of Science, to identify pertinent studies. We collected such patient data as demographic variables (including age, gender, body mass index), cervical spondylosis type (such as radiculopathy and myelopathy), diabetes status, smoking and drinking history, and radiological risk factors (such as preoperative ASD status, developmental spinal stenosis, T1 slope, and postoperative less cervical lordosis). Incidence estimates were calculated based on relevant data. Risk factors were assessed using odds ratios and weighted mean differences with 95% confidence intervals (CIs). Our analysis incorporated a total of 21 studies for incidence analysis. The overall incidence of CASD following ACDF was found to be 11% and radiographical ASD was 30%. Old age (weighted mean difference=3.21; 95% CI: 0.06, 6.36; P=0.05), preoperative ASD status (odds ratio=2.65; 95% CI: 1.53, 4.60; P < 0.01), developmental spinal stenosis (odds ratio=2.46; 95% CI: 1.61, 3.77; P < 0.01), and postoperative reduction in cervical lordosis were identified as significant risk factors for the occurrence of CASD. The incidence of CASD following ACDF was 11%. Risk factors for CASD included old age, preoperative adjacent segment degeneration, developmental spinal stenosis, and postoperative reduction in cervical lordosis. These findings provide valuable insights for the assessment of adjacent segment disease risk after ACDF, aiding surgeons in diagnosis and treatment decisions.

The Effect of Interbody Cage Parameters on the Rate of Subsidence in Single-Level Anterior Cervical Discectomy and Fusion (ACDF): A Retrospective Analysis of 98 Patients.

Subsidence is arelatively common consequence after anterior cervical discectomy and fusion (ACDF) surgery. This study aimed to identify the effect of radiological and non-radiological risk factors on subsidence after a single-level ACDF surgery with cage and plate. This is a retrospective cohort study of patients who underwent ACDF for radiculopathy or myelopathy at an academic center, University of Kentucky Albert Chandler Hospital, Lexington, Kentucky, United States, between January 2010 and January 2020.Subsidence was defined as the sinking of the interbody cage into the vertebral body at either the superior end plate (SEP) or inferior end plate (IEP) at the ACDF level and was measured manually on lateral standing x-ray. The numerical amount of subsidence was measured in millimeters as the sum of subsidence in the SEP and IEP and was further categorized into subsidence2 and subsidence3 (i.e., presence of subsidence > 2 mm and subsidence > 3 mm, respectively). Multivariateregression analysis was used to assess the effect of variables such as age, gender, body mass index (BMI), tobacco use, follow-up length, cage type, anterior cage height, posterior cage height, anterior cage height ratio, posterior cage height ratio, cage position, cage-end plate interface and cervical alignment on outcomes such as subsidence, subsidence2, and subsidence3. A total of 98 patients were included, of which 46 (47.1%) were male. The mean age of the population was 47.6±8.4 years. Fifty-one patients (52%) experienced subsidence more than 3 mm. Anterior disc height ratio (ADHR) was calculated by dividing the anterior cage height by the anterior disc height (pmADH). The posterior disc height ratio (PDHR) was calculated by dividing the posterior cage height by the posterior disc height (pmPDH). There was no significant correlation between ADHR and PDHR with subsidence, (p=0.93 and 0.56, respectively). Gender, age, BMI, and smoking status did not affect subsidence either. Cage type significantly affected subsidence with a higher subsidence rate in VG2 cages compared to Bengal cages (p=0.05). This study showed that in patients undergoing single-level ACDF with cage and plate, cage size and in particular cage height (if adjusted for individual patients) did not affect subsidence. Other factors such as cage-endplate interface, cage depth in interbody space, and cervical alignment did not significantly affect subsidence either. This might be attributable to the use of an anterior plating system that conducts the force and reduces the stress on the graft-bone interface.

Cervical Vertebral Bone Quality Score Independently Predicts Zero-Profile Cage Subsidence After Single-Level Anterior Cervical Discectomy and Fusion

ObjectiveThis is the first study to evaluate the predictive value of the cervical vertebral bone quality (VBQ) score on zero-profile cage (ZPC) subsidence after anterior cervical discectomy and fusion (ACDF) using the HU value of computed tomography (CT) as the reference. MethodsA total of 89 patients with at least 1 year of follow-up who underwent single-level ACDF with ZPC were retrospectively and consecutively included. VBQ and HU value were determined from preoperative T1-weighted MRI and CT. Subsidence was defined as ≥2 mm of migration of the cage into the superior or inferior endplate or both using lateral cervical spine radiography. The results were subjected to statistical analysis. ResultsSubsidence was observed among 16 of the 89 study patients (Subsidence rate:18.0%). The mean VBQ score was 2.94±0.820 for patients with subsidence and 2.33±0.814 for patients without subsidence. The multivariable analysis demonstrated that only an increased VBQ score (OR:1.823, 95%CI: 0.918,3.620, p=0.001) was associated with an increased rate of cage subsidence. There was a significant and moderate correlation between HU and VBQ (r = -0.507, P < 0.001). Using receiver operating characteristic curves, the area under the curve (AUC) was 0.785, and the most appropriate threshold of VBQ was 2.68 (sensitivity 72.7%, specificity 82.1%). ConclusionsThe VBQ score may be a valuable tool for independently predicting zero-profile cage subsidence after single-level ACDF.

A Matched-Cohort Analysis of Outcomes in Patients with Hereditary Hemochromatosis After Anterior Cervical Discectomy and Fusion

Hereditary hemochromatosis (HH) is a common autosomal recessive disorder. This disease affects gut iron transport, leading to iron overload, which affects immune function, coagulation mechanics, and bone health. Within the spine, HH contributes to decreased bone mineral density and accelerated intervertebral disc degeneration. The purpose of this study was to discover the differences in the rates of common 90-day postoperative complications and 1-year and 2-year surgical outcomes in patients with and without HH after anterior cervical discectomy and fusion (ACDF). Using the PearlDiver database, patients with active diagnoses of HH before ACDF were matched to patients without HH using a 1:5 ratio on the basis of age, sex, body mass index, and comorbidities. Postoperative complications were assessed at 90 days, and 1-year and 2-year surgical outcomes were assessed. All outcomes and complications were analyzed using multivariate logistic regression with significance achieved at P < 0.05. Patients with HH had significantly higher rates of 1-year and 2-year reoperation rates compared with patients without HH (29.19% vs. 3.94% and 37.1% vs. 5.93%, respectively; P < 0.001). The rates of 90-day postoperative complications significantly increased in patients with HH including dysphagia, pneumonia, cerebrovascular accident, deep vein thrombosis, acute kidney injury, urinary tract infection, hyponatremia, surgical site infection, iatrogenic deformity, emergency department visit, and hospital readmission. Patients with HH undergoing ACDF showed increased 90-day postoperative complications and significantly increased rates of 1-year and 2-year reoperation compared with patients without HH. These findings suggest that iron overload may contribute to adverse outcomes in patients with HH undergoing 1-level and 2-level ACDF.

Early Detection and Urgent Surgical Repair of Pharyngeal Injury after Anterior Cervical Surgery: A Case Report

This case report addresses pharyngeal perforation, an uncommon complication after anterior cervical discectomy and fusion (ACDF). A 78-year-old male, who initially presented with quadriparesis, underwent ACDF. Post-surgery, the porridge he consumed was observed in the drain tube, leading to complications such as respiratory distress and fever. An emergency exploratory surgery was performed, and a suspected pharyngeal perforation was identified and treated with primary repair and sternocleidomastoid flap. Through thorough post-operative observation, we identified critical signs requiring immediate intervention, allowing for a successful recovery without additional complications. This report emphasizes the importance of early detection and intervention for complications following ACDF, providing valuable insights for clinical practice in neurosurgical intensive care.

The impact of over-distraction on adjacent segment pathology and cage subsidence in anterior cervical discectomy and fusion

Over-distraction has been shown to be a risk factor for cage subsidence and postoperative neck pain after anterior cervical discectomy and fusion (ACDF). Biomechanical studies have demonstrated increased adjacent segment intradiscal pressure after ACDF. The purpose of this study is to determine if over-distraction of the index disc has an effect on adjacent segment pathology. A consecutive series of 145 patients who received primary ACDF for cervical degenerative pathologies from January 2010 to December 2017 were retrospectively reviewed. The patients were divided into: (1) Over-distraction group (postoperative–preoperative index disc height ≥ 2 mm), and (2) No-distraction group (postoperative–preoperative index disc height < 2 mm). Outcome measures included radiographic parameters, Japanese Orthopaedic Association (JOA) score, and incidences of cage subsidence, radiological and clinical adjacent segment pathologies (RASP and CASP) were compared between the two groups preoperatively, postoperatively, and at the final follow-up. The two groups were comparable with respect to age, follow-up length, JOA score, incidence of CASP, and radiographic parameters. The Over-distraction group (83 patients; 115 levels) had smaller preoperative index disc height (4.5 vs. 5.2 mm, p < 0.001), but taller postoperative index disc height (7.7 vs. 6.6 mm, p < 0.001) than No-distraction group (62 patients; 90 levels) Furthermore, significantly higher incidences of cage subsidence (47% vs. 31%, p = 0.04) and RASP (any progression: 48% vs. 15%, p < 0.001; progress ≥ 2 grades: 25% vs. 7%, p = 0.001) were observed in the Over-distraction group. The multivariate analysis indicated that over-distraction and multilevel fusion were independent risk factors for RASP. There were no clinical outcome differences between the Over-distraction group and the No-distraction group in ACDF. Over-distraction of the index level of ≥ 2 mm should be avoided because it significantly increases the incidences of RASP and cage subsidence.