Primary Anterior Cervical Discectomy Research Articles

Predictors of failure after primary anterior cervical discectomy and fusion for subaxial traumatic spine injuries.

Traumatic subaxial fractures account for more than half of all cervical spine injuries. The optimal surgical approach is a matter of debate and may include anterior, posterior or a combined anteroposterior (360º) approach. Analyzing a cohort of patients initially treated with anterior cervical discectomy and fusion (ACDF) for traumatic subaxial injuries, the study aimed to identify predictors for treatment failure and the subsequent need for supplementary posterior fusion (PF). A retrospective, single center, consecutive cohort study of all adult patients undergoing primary ACDF for traumatic subaxial cervical spine fractures between 2006 and 2018 was undertaken and 341 patients were included. Baseline clinical and radiological data for all included patients were analyzed and 11 cases of supplementary posterior fixation were identified. Patients were operated at a median of 2.0days from the trauma, undergoing 1-level (78%), 2-levels (16%) and ≥ 3-levels (6.2%) ACDF. A delayed supplementary PF was performed in 11 cases, due to ACDF failure. On univariable regression analysis, older age (p = 0.017), shorter stature (p = 0.031), posterior longitudinal ligament (PLL) injury (p = 0.004), injury to ligamentum flavum (p = 0.005), bilateral facet joint dislocation (p < 0.001) and traumatic cervical spondylolisthesis (p = 0.003) predicted ACDF failure. On the multivariable regression model, older age (p = 0.015), PLL injury (p = 0.048), and bilateral facet joint dislocation (p = 0.010) remained as independent predictors of ACDF failure. ACDF is safe and effective for the treatment of subaxial cervical spine fractures. High age, bilateral facet joint dislocation and traumatic PLL disruption are independent predictors of failure. We suggest increased vigilance regarding these cases.

Alterations in Swallowing Six Weeks After Primary Anterior Cervical Discectomy and Fusion (ACDF).

This aim of this study is to characterize the nature and pathophysiology of dysphagia after ACDF surgery by precisely and comprehensively capturing within-subject changes on videofluoroscopy between preoperative and postoperative time points. 21 adults undergoing planned primary ACDF procedures were prospectively recruited and enrolled. Participants underwent standardized preoperative and six-week postoperative videofluoroscopic swallow studies. Videos were blindly rated using the Penetration-Aspiration Scale (PAS) and analysis of total pharyngeal residue (%C2-42), swallowing timing, kinematics, and anatomic change was completed. Linear mixed-effects modeling was used to explore the relationships between possible predictor variables and functional outcomes of interest that changed across timepoints. There was no change in PAS scores across timepoints. Total pharyngeal residue (%C2-C42) was increased postoperatively (p < 0.001). Our statistical model revealed significant main effects for timepoint (p = 0.002), maximum pharyngeal constriction area (MPCAN) (p < 0.001), and maximum thickness of posterior pharyngeal (PPWTMAX) (p = 0.004) on the expression of total pharyngeal residue. There were significant two-way interactions for timepoint and MPCAN (p = 0.028), timepoint and PPWTMAX (p = 0.005), and MPCAN and PPWTMAX (p = 0.010). Unsurprisingly, we found a significant three-way interaction between these three predictors (p = 0.027). Our findings suggest that in planned ACDF procedures without known complications, swallowing efficiency is more likely to be impaired than airway protection six weeks after surgery. The manifestation of impaired swallowing efficiency at this timepoint appears to be driven by a complex relationship between reduced pharyngeal constriction and increased prevertebral edema.

Clinical Outcomes and Cost Differences Between Patients Undergoing Primary Anterior Cervical Discectomy and Fusion Procedures with Private or Medicare Insurance: A Propensity Score-Matched Study

We assessed whether the insurance type reflects a patient's quality of care after an anterior discectomy and fusion (ACDF) procedure by comparing differences in the postoperative complications, readmission rates, reoperation rates, lengths of hospital stay, and cost of treatment between patients with Medicare versus private insurance. Propensity score matching was used to match patient cohorts insured by Medicare and private insurance in the MarketScan Commercial Claims and Encounters Database (2007-2016). Age, sex, year of operation, geographic region, comorbidities, and operative factors were used to match cohorts of patients who had undergone an ACDF procedure. A total of 110,911 patients met the inclusion criteria. Of these patients, 97,543 patients (87.9%) were privately insured and 13,368 patients (12.1%) were insured by Medicare. The propensity score matching algorithm matched 7026 privately insured patients to 7026 Medicare patients. After matching, no significant differences were found in the 90-day postoperative complication rates, lengths of stay, or reoperation rates between the Medicare and privately insured cohorts. The Medicare group had had lower postoperative readmission rates for all time points: 30 days (1.8% vs. 4.6%; P < 0.001), 60 days (2.5% vs. 6.3%; P < 0.001), and 90 days (4.2% vs. 7.7%; P < 0.001). The median payment to physicians was significantly lower for the Medicare group ($3885 vs. $5601; P < 0.001). In the present study, propensity score matched patients covered by Medicare and private insurance who had undergone an ACDF procedure had had similar treatment outcomes.

Biomechanical Evaluation of Different Surgical Approaches for the Treatment of Adjacent Segment Diseases After Primary Anterior Cervical Discectomy and Fusion: A Finite Element Analysis.

Symptomatic adjacent segment disease (ASD) is a common challenge after anterior cervical discectomy and fusion (ACDF). The objective of this study was to compare the biomechanical effects of a second ACDF and laminoplasty for the treatment of ASD after primary ACDF. We developed a finite element (FE) model of the C2-T1 based on computed tomography images. The FE models of revision surgeries of ACDF and laminoplasty were simulated to treat one-level and two-level ASD after primary ACDF. The range of motion (ROM) and intradiscal pressure (IDP) of the adjacent segments, and stress in the cord were analyzed to investigate the biomechanical effects of the second ACDF and laminoplasty. The results indicated that revision surgery of one-level ACDF increased the ROM and IDP at the C2–C3 segment, whereas two-level ACDF significantly increased the ROM and IDP at the C2–C3 and C7-T1 segments. Furthermore, no significant changes in the ROM and IDP of the laminoplasty models were observed. The stress in the cord of the re-laminoplasty model decreased to some extent, which was higher than that of the re-ACDF model. In conclusion, both ACDF and laminoplasty can relieve the high level of stress in the spinal cord caused by ASD after primary ACDF, whereas ACDF can achieve better decompression effect. Revision surgery of the superior ACDF or the superior and inferior ACDF after the primary ACDF increased the ROM and IDP at the adjacent segments, which may be the reason for the high incidence of recurrent ASD after second ACDF.

The Effect of Esophageal Temperature Probes on Postoperative Dysphagia Following Primary Anterior Cervical Discectomy and Fusion: A Randomized Prospective Study.

The anterior approach to the cervical spine is associated with postoperative dysphagia. It is difficult to predict which patients are most at risk for dysphagia. The objective of this study was to determine if placing an esophageal temperature probe preoperatively would affect the severity and length of postoperative dysphagia. We hypothesize that use of an esophageal temperature probe would result in worse postoperative dysphagia at all measured time points as measured by the Swallowing-Quality of Life (SQAL-QOL) survey after anterior cervical discectomy and fusion (ACDF). A total of 44 patients were enrolled in a prospective, randomized controlled trial and randomized into groups: 1 with an esophageal temperature probe placed at the time of surgery and 2 without. A total of 39 patients filled out postoperative SWAL-QOL questionnaires at their preoperatives. Using the survey results, the data were analyzed between groups and subanalyzed based on number of operative levels and sex. SWAL-QOL scores for patients undergoing 2-level ACDF with an esophageal temperature probe were significantly better compared with those without a probe at 2 weeks and 6 months postoperatively. These results were not significant at other time points in in the overall analysis, but a trend toward improved dysphagia scores at each time point postoperatively was seen with the probe group. No differences were found between the 2 groups with respect to age at the time of surgery, sex, and preoperative SWAL-QOL score. Placement of an esophageal temperature probe at the time of surgery significantly improved postoperative dysphagia scores in patients undergoing 2-level ACDF at 2 weeks and 6 months postoperatively. 2 CLINICAL RELEVANCE: Placement of a temperature probe is a safe and effective technique that is readily available and easily applicable to the practice of spine surgery and may improve postoperative dysphagia after ACDF.

Influence of approach laterality to outcome of one to two level primary anterior cervical discectomy and fusion

Influence of approach laterality to outcome of one to two level primary anterior cervical discectomy and fusion

Patient Factors Affecting Emergency Department Utilization and Hospital Readmission Rates After Primary Anterior Cervical Discectomy and Fusion: A Review of 41,813 cases.

Retrospective database analysis. To identify preoperative risk factors for emergency department (ED) visit and unplanned hospital readmission after primary anterior cervical discectomy and fusion (ACDF) at 30 and 90 days. Limited data exist to identify factors associated with ED visit or readmission after primary ACDF within the first 3 months following surgery. Patients undergoing ACDF from 2005 to 2012 were identified in the Statewide Planning and Research Cooperative System database. Multivariable regression models were created based on patient-level and surgical characteristics to identify independent risk factors for hospital revisit. Of 41,813 patients identified, 2514 (6.0%) returned to the ED within 30 days of discharge. Risk factors included age < 35, black race (OR 1.19), Charlson Comorbidity index score > 1, length of stay (LOS) greater than 1 day (OR 1.23), and fusion of > 2 levels (OR 1.17). Four thousand six hundred nine (11.0%) patients returned to the ED within 90 days. Risk factors mirrored those at 30 days. Patients having private insurance or those discharged to rehab were less likely to present to the ED. One thousand three hundred ninety-four (3.3%) patients were readmitted by 30 days. Risk factors included male sex, Medicare, or Medicaid insurance (OR 1.71 and 1.79 respectively), Charlson comorbidity index > 1, discharge to a skilled nursing facility (OR 2.90), infectious/pathologic (OR 3.296), or traumatic (OR 1.409) surgical indication, LOS > 1 day (OR 1.66), or in-hospital complication. 2223 (5.3%) patients were readmitted by 90 days. Risk factors mirrored those at 30 days. No differences in readmission were seen based on race or number of levels fused. Patients aged 18 to 34 were less likely to be readmitted versus patients older than 35. Insurance status, comorbidities, and LOS consistently predicted an unplanned hospital visit at 30 and 90 days. Although nondegenerative surgical indications and in-hospital complications did not predict ED visits, these factors increased the risk for readmission. 3.

Effect of Steroid-Soaked Gelatin Sponge on Soft Tissue Swelling Following Anterior Cervical Discectomy and Fusion: A Radiographic Analysis

Study DesignRetrospective radiological review and analysis of 79 patients who underwent primary anterior cervical discectomy and fusion (ACDF) of 2 or 3 levels between 2011 and 2013.PurposeThis study aimed to determine the effect of the local placement of a steroid-soaked gelatin sponge after ACDF on prevertebral soft tissue swelling. Overview of LiteratureAlthough ACDF has become a popular choice for cervical fusion, the surgical involvement of the delicate anatomy of the neck frequently results in tissue irritation and edema. Swelling of the prevertebral soft tissue may consequently lead to mild-to-severe complications, ranging from dysphonia to dyspnea.MethodsOut of the 79 patients who underwent primary ACDF, 52 received a gelatin sponge soaked with 40 mg of Depo-Medrol placed adjacent to the operated cervical levels. Prevertebral soft tissue swelling was detected using postoperative lateral X-ray. The radiographic values were compared to those of 27 patients who did not receive the treatment.ResultsSoft tissue swelling was markedly decreased in patients who received the placement of the steroid-soaked gelatin sponge next to their fused levels after surgery compared with that in patients who did not receive it. No complications were documented with the use of steroids.ConclusionsThe placement of a steroid-soaked gelatin sponge markedly reduces postoperative soft tissue swelling following 2- or 3-level primary ACDF.

Recurrent Laryngeal Nerve Palsy Is More Frequent After Secondary than After Primary Anterior Cervical Discectomy and Fusion: Insights from a Registry of 525 Patients

Recurrent laryngeal nerve (RLN) palsy is a common complication after anterior cervical discectomy and fusion (ACDF) and usually manifests with dysphagia, hoarseness, and respiratory difficulties. Next to proven risk factors, such as age and multilevel procedures, RLN palsy has been speculated to occur more frequently after secondary ACDF procedures. We analyzed a prospective registry of all consecutive patients undergoing zero-profile ACDF for disc herniation, myelopathy, or stenosis. RLN palsy was defined as persistent patient self-reported dysphagia, hoarseness, or respiratory problems without other identifiable causes. RLN palsy was assessed at scheduled 6-week telephone interviews. Among 525 included patients, 511 primary and 40 secondary ACDF procedures were performed. Hoarseness was present in 12 (2.2%) cases, whereas dysphagia and respiratory difficulties both occurred in 3 (0.5%) cases. Overall incidence of RLN palsy was 2% after primary procedures and 8% after secondary procedures (P= 0.017). These rates are in line with the peer-reviewed literature, and the difference remained significant after controlling for confounders in a multivariate model (P= 0.033). Other reported risk factors, such as age, sex, surgical time, and multilevel procedures, had no relevant effect (P > 0.05). Based on our data and other published series in the literature, RLN palsy may occur more frequently after secondary ACDF procedures with a clinically relevant effect size. There is a striking lack of uniformity in methods and reporting in research on RLN injury.

The Association of Perioperative Glycemic Control with Deep Postoperative Infection After Anterior Cervical Discectomy and Fusion in Patients with Diabetes.

To evaluate the association of perioperative hemoglobin A1c (HbA1c) level in patients with diabetes with the incidence of infection after anterior cervical discectomy and fusion requiring operative intervention, in addition to determining if a threshold level of HbA1c above which the risk of infection increases significantly exists. A national administrative database was queried for patients who underwent primary anterior cervical discectomy and fusion with diabetes who had a perioperative HbA1c level recorded within 3 months of surgery. These patients were stratified based on their HbA1c level in 0.5-mg/dL increments from <5.49 mg/dL to >11.5 mg/dL. The incidence of infection requiring operative intervention within 1 year was then identified using Current Procedural Terminology and International Classification of Diseases, Ninth Revision codes. A receiver operating characteristic (ROC) analysis was performed to determine a threshold value of the HbA1c level. A total of 3341 patients with a perioperative HbA1c level were included. The rate of deep infection requiring irrigation and debridement postoperatively stratified by HbA1c level ranged from a low of 1.5% to a high of 6.4% and was significantly correlated with increasing HbA1c levels (P= 0.005). The results of ROC analysis determined that the inflection point of the ROC curve corresponded to an HbA1c level higher than 7.5 mg/dL (P= 0.022; area under the curve, 0.67; specificity, 68%; sensitivity, 46%). The risk of deep postoperative infection in patients with diabetes mellitus increases as the perioperative HbA1c level increases. ROC analysis determined that a perioperative HbA1c level higher than 7.5 mg/dL could serve as a threshold for a significantly increased risk of infection.

The Effect of Esophageal Contents on Postoperative Dysphagia Following Primary Anterior Cervical Discectomy and Fusion Surgery: A Prospective Randomized Trial

The Effect of Esophageal Contents on Postoperative Dysphagia Following Primary Anterior Cervical Discectomy and Fusion Surgery: A Prospective Randomized Trial

Is it feasible to treat unstable hangman's fracture via the primary standard anterior retropharyngeal approach?

The goal of this study was to evaluate the results and feasibility of primary anterior cervical discectomy and fusion (ACDF) with plating for unstable traumatic spondylolisthesis of the axis, the so-called hangman's fracture, via the standard anterior retropharyngeal approach. The clinical and radiological records of 17 patients (14 males and 3 females, mean age: 51 years, range 17-73 years) with unstable hangman's fracture who were treated between January 1996 and June 2012 were reviewed retrospectively. ACDF with plating at C2-3 level was performed in all patients (type II fracture: 12 patients, type IIA fracture: 3 patients and type III fracture: 2 patients, based on the Levine and Edwards classification). Combined morbidity, complications, neurological improvement and fusion rate were assessed. Seventeen patients underwent fusion surgery via the standard anterior retropharyngeal approach. Four patients required an additional posterior arthrodesis to augment the anterior procedure. Patients wore a Philadelphia collar for 4-6 weeks and fusion at C2-3 was achieved in all patients. Two cases of complications were observed during treatment, comprising of one case of non-union and one case of transient dysphagia that resolved after 3 months. However, none of the patients experienced worsening of the neurological function post-operatively. There were no cases of permanent nerve injury or infection. Treatment of the hangman's fracture is dependent on the stability of the injury. Although the treatment for unstable hangman's fracture is still controversial, we carefully suggest that primary ACDF with plating via the standard anterior retropharyngeal approach may be a feasible treatment option. It provides immediate stability and allows for early ambulation while promoting a stable bone union with minimal morbidity.

Accurately measuring the quality and effectiveness of cervical spine surgery in registry efforts: determining the most valid and responsive instruments

Background contextThere is a growing demand to measure the real-world effectiveness and value of care across all specialties and disease states. Prospective registries have emerged as a feasible way to capture real-world care across large patient populations. However, the proven validity of more robust and cumbersome patient-reported outcome instruments (PROi) must be balanced with what is feasible to apply in large-scale registry efforts. Hence, commercial registry efforts that measure quality and effectiveness of care in an attempt to guide quality improvement, pay for performance, or value-based purchasing should incorporate measures that most accurately represent patient-centered improvement. PurposeWe set out to establish the relative validity and responsiveness of common PROi in accurately determining effectiveness of cervical surgery for neck and arm pain in registry efforts. Study designProspective cohort study. Patient sampleEighty-eight patients undergoing primary anterior cervical discectomy and fusion (ACDF) for neck and arm pain. Outcome measuresPatient-reported outcome measures for pain (numeric rating scale for neck pain [NRS-NP] and arm pain [NRS-AP]), disability (neck disability index [NDI]), general health (short-form 12-item survey physical component summary [SF-12 PCS] and mental component summary [SF-12 MCS]), and quality of life (Euro-Qol-5D [EQ-5D]) were assessed. MethodsEighty-eight patients undergoing primary ACDF for neck and arm pain were entered into a Web-based prospective registry. Baseline and 12-month patient-reported outcomes (NRS-NP, NRS-AP, NDI, SF-12 PCS, SF-12 MCS, and EQ-5D) were assessed. Patients were also asked whether they experienced a level of improvement after ACDF that met their expectation (meaningful improvement). To assess the validity of NRS-NP, NRS-AP, and NDI (measures of pain and disability) to discriminate between meaningful and nonmeaningful improvement and the validity of SF-12 PCS, SF-12 MCS, and EQ-5D (measures of general health and quality of life) to discriminate between meaningful and nonmeaningful improvement, receiver-operating characteristic curves were generated for each outcome instrument. The greater the area under the curve (AUC), the more valid the discriminator. The difference between standardized response means (SRMs) in patients reporting meaningful improvement versus not was calculated to determine the relative responsiveness of each outcome instrument to changes in pain and QOL after surgery. ResultsFor pain and disability, both NDI (AUC=0.75) and NRS-AP (AUC=0.74) were valid discriminators of meaningful improvement. Numeric rating scale for neck pain (AUC=0.69) was a poor discriminator. Neck disability index was also most responsive to postoperative improvement (SRM difference 0.78), followed by NRS-AP (SRM difference 0.59) and NRS-NP (SRM difference 0.46). For general health and quality of life, SF-12 PCS (AUC=0.79) was the only valid discriminator of meaningful improvement. Euro-Qol-5D (AUC=0.68) and SF-12 MCS (AUC=0.44) were poor discriminators. Short-form 12 physical component summary (SRM difference 1.08) was also most responsive compared with EQ-5D (SRM difference 0.89) and SF-12 MCS (SRM difference 0.01). ConclusionsFor pain and disability, NDI is the most valid and responsive measure of improvement after surgery for neck and arm pain. Numeric rating scale for neck pain and NRS-AP are poor substitutes for NDI when measuring effectiveness of care in registry efforts. For health-related quality of life, only SF-12 PCS could accurately discriminate meaningful improvement after cervical surgery and was found to be most valid and responsive. Large-scale registry efforts aimed at measuring effectiveness of cervical spine surgery should use NDI and SF-12 to accurately assess improvements in pain, disability, and quality of life.

Effect of approach side during anterior cervical discectomy and fusion on the incidence of recurrent laryngeal nerve injury

This retrospective study was designed to determine whether side of approach during instrumented, one- or two-level primary anterior cervical discectomy and fusion (ACDF) affects the incidence of recurrent laryngeal nerve (RLN) injury diagnosed by observation of the vocal cords (OVC). Records of all patients who underwent one- or two-level instrumented primary ACDF (418 patients) between January 1995 and February 2004 were reviewed. Data collected from these charts included surgeon, patient demographics, preoperative diagnosis, side of exposure, number of vertebral levels fused, and presence of RLN injury diagnosed by OVC after referral for persistent dysphonia. Time from surgery to OVC for patients with right-sided exposures was not statistically different from that for patients with left-sided exposures. Of 418 patients, 278 (66.5%) had right-sided exposures and 140 (33.5%) had left-sided exposures. Eight RLN injuries (1.9%) were noted-five in patients with right-sided exposures (1.8%) and three in patients with left-sided exposures (2.1%). The difference between right- and left-sided injury rates was shown to be nonsignificant using Fisher exact tests. Results indicate that, given the study's sample size, side of approach during instrumented, one- or two-level primary ACDF has no significant effect on RLN injury incidence in patients with persistent dysphonia referred for OVC. The definitive answer regarding the true incidence of RLN injury relative to approach side awaits a prospective study with preoperative, immediate postoperative, and periodic OVC in a large, homogeneous population with sufficient numbers of patients with right- and left-sided approaches.