After Anterior Cervical Discectomy And Fusion Research Articles

Does titanium cage subsidence affect clinical outcomes in ACDF surgery? A tertiary centre experience.

Cage subsidence after anterior cervical discectomy and fusion (ACDF) surgery has been well documented with rates of up to 40%. Cages fill the void after cervical discectomy and promote fusion. These materials have different biomechanical profiles with differing rates of subsidence. This retrospective cohort study aimed to determine subsidence rates specifically associated with the novel Emerging Implant Technologies (EIT) titanium cage, identify risk factors associated with subsidence, and evaluate whether subsidence affects clinical outcomes. ACDF with insertion of stand-alone EIT cage was performed in 39 patients (64 levels) between December 2016 and February 2019 with a median follow-up of 11 months. Patients were classified into two groups; subsidence and non-subsidence, and were compared in terms of the resultant clinical outcomes as well as presence of risk factors. Health-related quality of life (HRQOL) outcomes were assessed using Visual Analogue Scale (VAS) for neck and arm pain, EuroQol 5-Dimension 5-Level (EQ-5D-5L), EuroQol Visual Analogue Scale (EQ VAS) and Neck Disability Index (NDI) scores. Cage subsidence (>3mm) was present in nine patients (23%), which corresponded to ten levels treated (16%). Development of subsidence was not associated with gender (p = 0.12), age (p = 0.27), smoking (p = 0.13), number of treatment levels (p = 0.10) or cage size used (p = 0.34). It had no effect on any of the HRQOL outcomes, namely VAS Neck (p = 0.07), VAS Arms (p = 0.08), EQ-5D-5L (p = 0.36), EQ VAS (p = 0.85) and NDI (p = 0.80). The EIT cage seems to be associated with lower rates of subsidence compared with other cage types. Cage subsidence was not associated with HRQOL outcomes or risk factors.

Subsidence following cervical discectomy and implant-to-bone ratio

BackgroundImplant subsidence is an undesirable effect after anterior cervical discectomy and fusion (ACDF). We investigated the relation between the rate of implant subsidence and the ratio of the implant surface area to the surface area of the adjacent bone.MethodsWe operated 170 disc spaces in a group of 104 patients. Two types of implants were used: 1) PEEK (polyetheretherketone) cages and 2) titanium-coated (TC) PEEK cages. Patients were randomised to receive a specific implant using a randomisation table. All implants had a surface area of 1.61 cm2. Based on computed tomography images, bone surface areas were calculated for vertebral bodies immediately adjacent to the interbody implants. The implant-to-bone surface ratio was then calculated for each disc space. Implant subsidence was assessed over 12 months of follow-up, and associations between implant subsidence, the type of implant, and the implant-to-bone surface ratio were investigated.ResultsTwelve months after the surgery, computed tomography was performed on 86 patients (144 disc spaces). Furthermore, in 166 disc spaces and 102 patients, conventional radiographs were obtained.Subsidence was observed in 21% of the examined intervertebral spaces, and it was more frequently associated with higher values of bone surface area and lower values of the implant-to-bone surface ratio. The type of implant (PEEK vs TC-PEEK cages) did not significantly influence the rate of implant subsidence.ConclusionsImplant subsidence was significantly related to the value of a coefficient representing the ratio of the implant's surface area to the bone surface area of the adjacent vertebral bodies, with subsidence occurring significantly more rarely for coefficient values ≥ 0.37.

In Vivo Evidence of Early Instability and Late Stabilization in Motion Segments Immediately Superior to Anterior Cervical Arthrodesis.

Prospective cohort study. The aim was to identify patient factors that affect adjacent segment kinematics after anterior cervical discectomy and fusion (ACDF) as measured by biplane radiography. The etiology of adjacent segment disease (ASD) may be multifactorial. Previous studies have investigated associations between patient factors and ASD, although few attempted to link patient factors with mechanical changes in the spine that may explain ASD development. Previous studies manually measured intervertebral motion from static flexion/extension radiographs, however, manual measurements are unreliable, and those studies failed to measure intervertebral motion during rotation. Patients had continuous cervical spine flexion/extension and axial rotation movements captured at 30 images per second in a dynamic biplane radiography system preoperatively and 1 year after ACDF. Digitally reconstructed radiographs generated from subject-specific computed tomography scans were matched to the biplane radiographs using a validated tracking process. Dynamic kinematics and preoperative disc height were calculated from this tracking process. Preoperative magnetic resonance imagings were evaluated for disc bulge. Patient age, sex, body mass index, smoking status, diabetes, psychiatric history, presence of an inciting event, and length of symptoms were collected. Multivariate linear regression was performed to identify patient factors associated with 1-year postoperative changes in adjacent segment kinematics. Sixty-three patients completed preoperative and postoperative testing. Superior adjacent segment disc height and disc bulge predicted the change in superior adjacent segment range of motion after surgery. Inferior adjacent segment disc bulge, smoking history, and the use of psychiatric medications predicted the change in inferior adjacent segment flexion/extension range of motion after surgery. Preexisting adjacent segment disc degeneration, as indicated by disc height and disc bulge, was associated with reduced adjacent segment motion after ACDF, while lack of preexisting adjacent disc degeneration was associated with increased adjacent segment motion after ACDF. These findings provide in vivo evidence supporting early instability and late stabilization in the pathophysiology of disc degeneration.

Biomechanical Analysis of the Reasonable Cervical Range of Motion to Prevent Non-Fusion Segmental Degeneration After Single-Level ACDF

The compensatory increase in intervertebral range of motion (ROM) after cervical fusion can increase facet joint force (FJF) and intradiscal pressure (IDP) in non-fusion segments. Guiding the post-ACDF patient cervical exercise within a specific ROM (defined as reasonable ROM) to offset the increase in FJF and IDP may help prevent segmental degeneration. This study aimed to determine the reasonable total C0–C7 ROM without an increase in FJF and IDP in non-fusion segments after anterior cervical discectomy and fusion (ACDF). A three-dimensional intact finite element model of C0–C7 generated healthy cervical conditions. This was modified to the ACDF model by simulating the actual surgery at C5–C6. A 1.0 Nm moment and 73.6 N follower load were applied to the intact model to determine the ROMs. A displacement load was applied to the ACDF model under the same follower load, resulting in a total C0–C7 ROM similar to that of the intact model. The reasonable ROMs in the ACDF model were calculated using the fitting function. The results indicated that the intervertebral ROM of all non-fusion levels was increased in the ACDF model in all motion directions. The compensatory increase in ROM in adjacent segments (C4/5 and C6/7) was more significant than that in non-adjacent segments, except for C3/4 during lateral bending. The intervertebral FJF and IDP of C0–C7 increased with increasing ROM. The reasonable ROMs in the ACDF model were 42.4°, 52.6°, 28.4°, and 42.25° in flexion, extension, lateral bending, and axial rotation, respectively, with a decreased ROM of 4.4–7.2%. The postoperative increase in FJF and IDP in non-fusion segments can be canceled out by reducing the intervertebral ROM within reasonable ROMs. This study provided a new method to estimate the reasonable ROMs after ACDF from a biomechanical perspective, and further in vitro and clinical studies are needed to confirm this.

Symptomatic postoperative spinal epidural hematoma preferentially occurs after anterior cervical discectomy and fusion versus anterior cervical corpectomy and fusion: a retrospective study.

Cervical spondylotic myelopathy (CSM) is a common cause of neurological morbidity, which can have an impact on quality of life. Symptomatic postoperative spinal epidural hematoma (SPSEH) is a rare condition, but can cause permanent neurological deficits and disability if not managed properly. However, there are limited studies on the outcomes of SPSEH after anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF) were performed for 2-level CSM. Therefore, the aim of the present study was to compare the clinical outcomes and incidence of SPSEH after ACDF compared with SPSEH after anterior cervical corpectomy and ACCF for 2-level CSM to reduce surgical complications of 2 level CSM. A total of 551 patients (261 males and 290 females) who underwent ACDF or ACCF for 2-level CSM from January 2009 to February 2015 were retrospectively reviewed. Preoperative indexes (age, sex, body mass index, bone mineral density, preoperative coagulation, and past medical history), perioperative indexes (length of hospital admission, blood loss, and operation times), preoperative and postoperative neurological statuses, complications, fusion rate, and the SPSEH incidence for ACDF or ACCF were compared simultaneously. With the exception of blood loss (P<0.001), no significant differences were observed between the 2 groups in terms of sex, prothrombin time, activated partial thromboplastin time, platelet count, length of hospital admission, operation time, the final follow-up Japanese Orthopedic Association score, visual analog scale score, fusion rate, and complications. The overall incidence rate for SPSEH after ACDF was 1.9%, while the rate for SPSEH after ACCF was 0.4%. Following hematoma removal, only one patient showed any improvement in neurological function, despite treatment with hyperbaric oxygen and neurotrophic drugs. The findings indicated that surgical management of 2-level CSM using ACDF or ACCF showed similar clinical outcomes, fusion rate, complications, and perioperative parameters, with the exception of blood loss. However, SPSEH preferentially occurs after surgery with ACDF. Therefore, whether ACCF surgery for 2-stage CSM is the superior treatment modality.

0823 ACDF - A hidden etiology of OSA

Abstract Introduction OSA is characterized by recurrent episodes of upper airway collapse and obstruction during sleep, leading to oxygen desaturations. Risk factors include obesity, age, sex, family history, craniofacial abnormalities, stroke, diabetes, polycystic ovarian syndrome. This case illustrates symptomatic and clinically proven worsening of OSA after anterior cervical discectomy and fusion (ACDF), which can lead to narrowing of the airspace and dysfunction of the pharyngeal plexus leading to upper airway collapse. Report of Cases: A 49-year-old female with cervical myelopathy was evaluated in the sleep clinic for snoring, witnessed apnea, and daytime somnolence. Her Epworth score was 11, and Mallampati score was 4, suggestive of underlying sleep-disordered breathing (SDB). A home diagnostic sleep test revealed mild OSA with AHI of 6.8/hr and was started on an Auto Continuous Positive Airway Pressure (APAP) device. She then reported worsening of her cervical pain leading to decreased use of APAP and total sleep time and underwent ACDF approximately 6 months after her diagnosis of OSA was made. Post-surgery she reported mild dysphagia, frequent nighttime awakening due to a choking sensation, and an increase in snoring. Following hospital discharge, the patient was re-evaluated in the sleep clinic for these complaints. Upon review, her BMI had decreased to 33.99 kg/m2, from 37.35 kg/m2, and the only medication change was the addition of hydrocodone-acetaminophen 5-325, 1-2 times daily as needed for pain. A repeat diagnostic home sleep study showed progression of OSA to moderate severity with an AHI of 24.5/hr, with no evidence of central sleep apnea or hypoventilation. Therefore, it was unlikely that the worsening of AHI was due to opioids. Thus, it was concluded that ACDF most likely led to the worsening of OSA. Conclusion Although there is no strong association in medical or sleep literature, this case demonstrates a strong association between ACDF and OSA. This highlights the importance of a timely diagnosis of new-onset or reassessment for worsening OSA in patients post-ACDF to improve sleep quality and prevent morbidity. Support (If Any)

What is the role of dynamic cervical spine radiographs in predicting pseudarthrosis revision following anterior cervical discectomy and fusion?

Background ContextPostoperative dynamic radiographs are used to assess fusion status after anterior cervical discectomy and fusion (ACDF) with comparable accuracy to computed tomography (CT) scans. PurposeTo (1) determine if dynamic radiographs accurately predict pseudarthrosis revision in a cohort of largely asymptomatic patients who underwent ACDF, (2) determine how adjacent segment motion is affected by fusion status, and (3) analyze how clinical outcomes differ between patients with symptomatic and asymptomatic pseudarthrosis. Study DesignRetrospective cohort study. Patient SamplePatients ≥ 18 years who underwent primary one- to four-level ACDF at a single institution over a 10-year period. Outcome MeasuresInterspinous motion on preoperative and postoperative flexion-extension radiographs and preoperative and postoperative Visual Analogue Scale for Neck Pain (VAS Neck) and Arm Pain (VAS Arm), Neck Disability Index (NDI), Modified Japanese Orthopaedic Association scale (mJOA), Mental and Physical Component Scores of the Short-Form 12 (SF-12) Health Survey (MCS-12 and PCS-12) MethodsThe difference in spinous process motion between flexion and extension radiographs was used to determine motion at each level of the ACDF construct. Pseudarthrosis was defined as ≥ 1 mm spinous process motion on dynamic radiographs. A receiver operating characteristic (ROC) curve was generated to predict the probability of surgical revision for pseudarthrosis based on millimeters of interspinous motion at each instrumented level. Patient reported outcome measures (PROMs) were used to assess the effect of pseudarthrosis on clinical outcomes. Alpha was set at p<.05. ResultsA total of 597 patients met inclusion criteria including 1,203 ACDF levels. Of those, 215 patients (36.0%) were diagnosed with a pseudarthrosis on dynamic radiographs with 29 patients (4.9%) requiring pseudarthrosis revision. ROC analysis identified a “cutoff” value of 1.00 mm of interspinous process motion for generating an optimal area under the curve (AUC). The negative predictive value (NPV) was 99.6%, whereas the positive predictive value (PPV) was 13.7%. When analyzing adjacent segment motion, the Δ supra-adjacent interspinous process motion (ISM) was significantly lower for patients with a superior construct pseudarthrosis (-1.06 mm vs. 1.80 mm, p<.001), whereas the Δ infra-adjacent level ISM was significantly lower for patients with an inferior construct pseudarthrosis (-1.21 mm vs. 2.15 mm, p<.001). Patients with a pseudarthrosis not requiring revision had worse postoperative NDI (29.3 vs. 23.4, p=.027), VAS Neck (3.40 vs. 2.63, p=.012), and VAS Arm (3.09 vs. 1.85, p=.001) scores at 3 months, but not 1-year, compared with patients who were fused. Patients requiring pseudarthrosis revision had higher 1-year postoperative NDI (38.0 vs. 23.7, p=.047) and lower 1-year postoperative Δ VAS Arm (-0.22 vs. -2.97, p=.016) scores. ConclusionsOne-year postoperative dynamic radiographs have a greater than 99% negative predictive value for identifying patients requiring pseudarthrosis revision, but they have a low positive predictive value. Most patients with a pseudarthrosis remain asymptomatic with similar 1-year postoperative patient-reported outcomes compared with patients without a pseudarthrosis.

Radiological and Clinical Outcomes after Anterior Cervical Discectomy and Fusion (ACDF) with an Innovative 3D Printed Cellular Titanium Cage Filled with Vertebral Bone Marrow.

Objectives To assess the clinical and radiological outcomes after ACDF with 3D printed cellular titanium cages filled with bone marrow and to compare the clinical and radiological results with the current scientific literature. Methods ACDF was performed monosegmentally under standardized conditions. X-rays were analyzed to determine the range of motion, fusion rates, and subsidence preoperatively and 3 and 12 months postoperatively. Clinical outcome measurements included neck disability index (NDI), visual analogue scale (VAS) for brachialgia and cervicalgia, and patient satisfaction. Results 18 patients were included in the study. The mean RoM decreased from 7.7° ± 2.6 preoperatively to 1.7° ± 1.1° after 3 months and 1.8° ± 1.2° 12 months after surgery. The fusion rates were at 94.4% after 3 and 12 months. The mean subsidence was 0.9 mm ± 0.5 mm 3 months postoperatively and 1.1 mm ± 0.5 mm 12 months after surgery. The mean NDI improved significantly from preoperatively to 12 months postoperatively (34.6 ± 6.2 and 3.4 ± 4.1, respectively). The VAS-neck also showed a large improvement from 5.8 ± 2.2 before and 1.3 ± 1.4 12 months after surgery, as did the VAS-arm (6.4 ± 1.5 and 0.9 ± 1.6, respectively). Patient satisfaction was high throughout the follow-up period. Conclusion ACDF with a 3D printed titanium cage resulted in fast fusion without pathological subsidence. In comparison to other cage materials such as PEEK, the 3D printed titanium cage was noninferior in regard to its fusion rate and clinical results.

Neck Disability at Presentation Influences Long-Term Clinical Improvement for Neck Pain, Arm Pain, Disability, and Physical Function in Patients Undergoing Anterior Cervical Discectomy and Fusion

To compare perioperative characteristics, patient-reported outcome measures (PROMs) and minimum clinically important difference (MCID) achievement after anterior cervical discectomy and fusion (ACDF) in patients stratified by preoperative neck disability. The Neck Disability Index (NDI) assesses a patient's self-perceived neck disability and is often used to assess the efficacy of cervical surgical intervention. Our study (a retrospective cohort study) evaluates how preoperative severity of patient neck disability influences postoperative clinical improvement after ACDF. Primary, single-level, or multilevel ACDF procedures were included. PROMs were administered at preoperative/6 week/12 week/6 month/1 year/2 year time points and included Patient-Reported Outcome Measurement Information System-Physical Function (PROMIS-PF), visual analog scale (VAS) for neck and arm pain, NDI, and 12-Item Short-Form (SF-12) Physical Composite Score (PCS). Patients were grouped according to preoperative NDI <50 (mild to moderate neck disability) or NDI ≥50 (severe neck disability). Demographics/perioperative characteristics/postoperative complications/mean PROMs/MCID achievement rates were compared using χ2 or Student t test. Postoperative improvement from preoperative baseline within each cohort was assessed with paired-samples t test. MCID achievement was determined by comparing ΔPROMs with established thresholds. A total of 225 patients were included, 150 NDI <50 and 75 NDI ≥50. The NDI ≥50 cohort was significantly younger (P= 0.002). Cohorts did not differ for spinal disease/operative duration/estimated blood loss/postoperative length of stay/postoperative narcotic consumption/adjacent segment disease rate/1-year arthrodesis rate/6-month pseudarthrosis rate. Postoperative VAS pain score on postoperative day 0 and 1 was significantly increased in the NDI ≥50 cohort (P<0.048, all). Postoperative complication rates did not differ. All mean PROMs differed at all time points (P<0.043, all). The NDI <50 patient cohort significantly improved from preoperative baseline for all PROMs and time points except SF-12 PCS/Patient-Reported Outcome Measurement Information System-Physical Function at 6 weeks. The NDI ≥50 cohort significantly improved for all PROMs and time points except SF-12 PCS at 6 weeks. The NDI ≥50 cohort showed a greater proportion achieving MCID for NDI at 6 weeks/2 years/overall (P<0.037, all). Both cohorts showed significant long-term clinical improvement for neck pain/arm pain/physical function/neck disability, although patients with severe preoperative neck disability reported inferior mean scores for these outcomes at all time points.

The Effect of Preoperative Mental Health Status on Outcomes After Anterior Cervical Discectomy and Fusion.

The effect of preoperative mental health on outcomes after anterior cervical discectomy and fusion (ACDF) is of increasing interest. The purpose of this study was to utilize patient-reported outcome measures (PROMs) to compare outcomes after ACDF in patients with and without poor mental health. We hypothesized that patients with worse baseline mental health would report worse outcomes after surgery. Patients undergoing ACDF for degenerative cervical spondylosis with at least 12 months of follow-up were included. Outcomes collected before and after surgery included the RAND-36, Neck Disability Index (NDI), EuroQol 5-dimension (EQ-5D), and Single Assessment Numeric Evaluation (SANE) score. Seventy-one patients were included and assigned to the depression or nondepression group based on baseline mental health. The depression group had worse baseline preoperative scores across all PROMs: NDI (44.2 vs 36.8, P = 0.05), RAND (1511.4 vs 2198.18, P < 0.001), EQ-5D (12.55 vs 10.14, P < 0.001), and SANE (56.3 vs 72.9, P < 0.001). Postoperatively, the depression group had worse scores at the final follow-up for RAND (2242.8 vs 2662.2, P = 0.03) and SANE (71.5 vs 80.8, P = 0.02). Both groups experienced improvements with ACDF across all PROMs. The changes in each PROM were not statistically significant between groups. There were no statistically significant differences in the percentage of patients achieving the minimal clinically important difference across PROMs. This study is the first to utilize the RAND-36, EQ-5D, NDI, and SANE scores to assess preoperative mental health and its effect on postoperative outcomes after ACDF. While poor preoperative mental health status yielded significantly worse baseline and postoperative outcomes scores, patients experienced significant improvement in symptoms after ACDF. Clinicians should be aware of the effects of poor mental health status on clinical outcomes in patients undergoing anterior cervical fusion, but can still expect significant clinical improvements after surgery.

Do Inflammatory Cytokines Affect Patient Outcomes After ACDF?

Prospective cohort study. The aim was to determine the relationship between serum inflammatory mediators, preoperative cervical spine disease severity, and clinical outcomes after anterior cervical discectomy and fusion (ACDF). Given the role of the inflammatory cascade in spinal degenerative disease, it has been hypothesized that inflammatory markers may serve as a predictor of patient outcomes after surgery. All patients over age 18 who underwent ACDF for cervical spondylosis with associated radiculopathy and/or myelopathy between 2015 and 2017 from a single institution were prospectively recruited. Preoperative serum inflammatory markers including interleukin (IL)-6, IL-8, tumor necrosis factor-α, high-mobility group box-1 (HMGB1), and white blood cells were measured and correlated to patient demographics, surgical characteristics, duration of symptoms, previous opioid use, and preoperative and 1-year postoperative patient-reported outcomes measures (PROMs) including the neck disability index (NDI), visual analog scale neck pain, visual analog scale arm pain, and Physical and Mental Component Scores of the Short Form-12 (PCS and MCS, respectively) using spearman's rho coefficient. A total of 77 patients were enrolled with follow-up PROMs available for 62% (n=48) of patients at a minimum of 1-year after ACDF. The absolute concentrations of IL-6 and tumor necrosis factor-α were found to be weakly correlated with one another (ρ=0.479). Preoperative symptoms lasting <1-year were weakly correlated with elevation in HMGB1 (ρ=0.421). All other patient demographics exhibited negligible correlation with the preoperative inflammatory markers. Lower preoperative PCS (ρ=0.355) and higher preoperative NDI (ρ=0.336) were weakly correlated with elevated HMGB1. Lower MCS (ρ=0.395) and higher NDI (ρ=0.317) preoperatively were weakly correlated with elevated white blood cells. Postoperative improvement in MCS (ρ=0.306) and MCS recovery ratio (ρ=0.321) exhibited a weakly positive correlation with IL-6. Preoperative cytokine levels demonstrated minimal correlation with preoperative symptoms or clinical improvement, suggesting that profiling of patient cytokines has limited utility in predicting outcomes after ACDF. Level III.

How Do Patients With Predominant Neck Pain Improve After Anterior Cervical Discectomy and Fusion for Cervical Radiculopathy?

The presence of predominant pain in the arm vs the neck as a predictor of postoperative outcomes after anterior cervical discectomy and fusion (ACDF) has been seldom reported; therefore, the purpose of this study was to determine whether patients with predominant neck pain improve after surgery compared to patients with predominant arm pain or those with mixed symptoms in patients undergoing ACDF for radiculopathy. A retrospective cohort study was conducted on patients who underwent ACDF at a single center from 2016 to 2018. Patients were split into groups based on preoperative neck and arm pain scores: neck (N) pain dominant group (visual analog scale [VAS] neck ≥ VAS arm by 1.0 point); neutral group (VAS neck < VAS arm by 1.0 point); or arm (A) pain dominant group (VAS arm ≥ VAS neck by 1.0 point), using a threshold difference of 1.0 point. Subsequently, individuals were substratified into 2 groups based on the arm to neck pain ratio (ANR): non-arm pain dominant defined as ANR ≤1.0 and arm pain dominant (APD) defined as ANR >1.0. Patient-reported outcome measurements including Neck Disability Index (NDI), Physical Component Score-12, and Mental Component Score (MCS-12) were compared between groups. No significant differences between groups when stratifying patients using a threshold difference of 1.0 point. When stratifying patients using the ANR, those in the APD group had significantly higher postoperative MCS-12 (P = 0.008) and NDI (P = 0.011) scores. In addition, the APD group showed a greater magnitude of improvement for MCS-12 and NDI scores (P = 0.043 and P = 0.038, respectively). Multiple linear regression showed that the A and the APD groups were both independent predictors of improvement in NDI. Patients with dominant arm pain showed significantly greater improvement in terms of MCS-12 and NDI scores compared to patients with dominant neck pain. To compare the impact of ACDF on arm and neck pain in the context of cervical radiculopathy using patient-reported outcome measures as an objective measurement.

Penicillin Allergy in Spine Surgery: Increased Rates of Sepsis, Emergency Room Visits, and Readmission

To determine if a penicillin allergy is an independent risk factor for poor outcomes after anterior cervical discectomy and fusion (ACDF) and posterior lumbar fusion (PLF). A retrospective database review was performed using the PearlDiver data set. The study population included all patients younger than 85 years who underwent elective PLF or ACDF with diagnosis of penicillin allergy using International Classification of Diseases codes. Study patients were compared with controls for 90-day complications and 1-year reoperation rates. A multivariate logistic regression was used to determine the independent effect of penicillin allergy on the postoperative outcomes. PLF cohort multivariate analysis showed that patients with a penicillin allergy had a significantly increased risk of sepsis (2.6% vs. 2.0%; P= 0.020), urinary tract infection (10.8% vs. 8.4%; P < 0.001), emergency room visits (27.3% vs. 20.2%; P < 0.001), and readmissions (9.6% vs. 6.4%; P < 0.001) within 90 days index of surgery. Similarly, the ACDF cohort multivariate analysis showed that a penicillin allergy was associated with an increased risk of sepsis (1.8% vs. 1.1%; P < 0.001), emergency room visits (27.2% vs. 20.7%; P < 0.001), and readmissions (6.8% vs. 5.6%; P= 0.003) within 90 days index of surgery. The present study found that a reported penicillin allergy is associated with an increase in sepsis, urinary tract infection, emergency room visit, and readmission postoperatively within 90 days after PLF and ACDF. The findings can help physicians provide patients with more comprehensive preoperative counseling in the setting of patient-reported penicillin allergy.

How to reconstruct the lordosis of cervical spine in patients with Hirayama disease? A finite element analysis of biomechanical changes focusing on adjacent segments after anterior cervical discectomy and fusion

PurposeTo compare the biomechanical changes of adjacent segments between patients with Hirayama disease and non-pathological people after anterior cervical discectomy and fusion (ACDF) operation, and to explore the optimal degree of local lordosis reconstruction during surgery.MethodsA young male volunteer was recruited to establish a three-dimensional finite element model of the lower cervical spine based on the CT data. By adjusting the bony structures and simulating the operation process, the models of non-pathological individuals before and after ACDF, patients with Hirayama disease before and after ACDF, and different local lordosis angles were established. Then, the postoperative range of motion (RoM) and stress of the adjacent segments under flexion, extension, left bending, right bending, left rotation and right rotation were recorded and compared.ResultsThe RoM and stress of all segments of lower cervical spine in patients with Hirayama disease are higher than those in non-pathological individual, and this trend still exists after ACDF surgery. When the local lordosis angle is under physiological conditions, the RoM and stress of the adjacent segments are minimum.ConclusionCompared with non-pathological people, Hirayama disease patients have differences in cervical biomechanics, which may lead to cervical hypermobility and overload. After ACDF, the possibility of adjacent segments degeneration is greater than that of non-pathological people. When the operation maintains the physiological local lordosis angle, it can slow down the degeneration.

The effects of pathology and one-level versus two-level arthrodesis on cervical spine intervertebral helical axis of motion

The etiology of adjacent segment disease after anterior cervical discectomy and fusion (ACDF) remains controversial. Range of motion (ROM) is typically used to infer the effects of arthrodesis on adjacent segment motion following ACDF, however, ROM only measures the total amount of motion. In contrast, the helical axis of motion (HAM) quantifies how the motion occurs and may provide additional insight into the etiology of adjacent segment pathology. Synchronized biplane radiographs of the cervical spine were acquired at 30 images per second while 62 ACDF patients and 38 control participants performed dynamic neck flexion/extension. A validated tracking process matched digitally reconstructed radiographs created from subject-specific bone models to the radiographs with sub-millimeter accuracy. The intervertebral HAM was then calculated and compared between pre and 1 year post surgery in patients, and between patients and controls at corresponding motion segments using linear mixed-effects analysis. Small differences in the anterior/posterior location of the HAM were found between the symptomatic motion segments before surgery and corresponding motion segments in controls. No changes in the HAM of motion segments adjacent to the arthrodesis were observed from pre to 1-year post-surgery. No differences in adjacent segment HAM were found between patients with one- versus two-level arthrodesis. Neither symptomatic pathology nor arthrodesis appear to change the way motion occurs in the cervical spine during flexion/extension one year after one or two-level arthrodesis. These results suggest ACDF does not alter short-term adjacent segment kinematics in a way that would contribute to the development of adjacent segment disease.

Progression of Ossification of Posterior Longitudinal Ligament After Anterior Cervical Discectomy and Fusion in Military Patients Exposed to Minor Trauma.

Ossification of the posterior longitudinal ligament (OPLL) can progress even after cervical spine surgery and may cause neurological injury as a result of minor trauma. The purpose of this study was to investigate the preventive factors associated with OPLL progression after anterior cervical discectomy and fusion (ACDF), a procedure commonly performed in clinical practice. We retrospectively investigated 295 male soldiers who underwent ACDF surgery between 2012 and 2017. Patients who were followed up for >12 months using dynamic radiography and computed tomography (CT) were included in the study. Radiological parameters investigated included OPLL progression, C2-C7 angles on dynamic radiography, segmental angles, C2-C7 cervical sagittal vertical axis (C2-C7 SVA), and the T1 slope. These parameters were measured preoperatively and 1 year postoperatively. A total of 49 patients were enrolled, and 10 patients were confirmed to have OPLL progression. Comparison between the OPLL progression and non-progression groups showed no statistically significant differences in pre- and postoperative cervical range of motion. However, statistically significant differences were observed in the postoperative neutral C2-C7 angle (progression -3.9°±6.4° vs. non-progression -13.4°±7.9°, p=0.001) and the SVA change (progression 5.8±7.9 mm vs. non-progression -3.7±6.3 mm, p=0.00). The cutoff values were -8.01° for the postoperative neutral C2-C7 angle and 1.4 mm for SVA changes. Increased SVA (>1.4 mm) and a small postoperative neutral C2-C7 angle (>-8.01°) 1 year after ACDF were associated with OPLL progression. It is important to be mindful of these factors during follow-up after ACDF, because additional surgical treatment may be necessary for OPLL progression due to neurological injury caused by minor trauma.

The Effects of Rehabilitation Following Anterior Cervical Microdiscectomy and Fusion Surgery.

To determine the effects of physical therapy and exercise programs that was performed after anterior cervical discectomy and fusion (ACDF) surgery on patient?s pain treatment, a retrospective study was designed. Of the 127 patients without neurological deficit who underwent ACDF surgery in our clinic in 2019 and 2020 for single-level cervical disc herniation, 40 patients (including 23 men and 17 women) were enrolled. The mean age of the patients was 45.5 years. The patients were separated into two groups. Group A comprised 20 patients who did not apply for a post-ACDF physical therapy and exercise program. Group B comprised 20 patients who applied for a 6-month post-ACDF physical therapy and exercise program and complied with it. The Oswestry Deficiency Index (ODI), visual analog pain scale (VAS), and C2-7 cervical lordosis angle were evaluated. The C2-7 cervical lordosis angles were individually calibrated and calculated for each patient using Surgimap. The relationships between the results were compared using Wilcoxon biostatistics test. The ODI, VAS, and C2-7 cervical lordosis angle parameters of Groups A and B were statistically compared. No significant differences in the ODI, VAS, and C2-7 cervical lordosis angle 2 days after surgery and C2-7 cervical lordosis angle 6 months after surgery were observed between the two groups; however, significant differences were observed in VAS and ODI values 6 months after physical therapy in Group B and in VAS and ODI values 6 months after surgery in Group A. No significant difference in C2-7 cervical lordosis angle 6 months after surgery was observed between post-physical therapy Group B and postoperative Group A. Physical therapy and exercise program performed early after ACDF enhances and improves pain management and does not cause any changes in the restoration of cervical misalignment.

Tracheostomy Following Anterior Cervical Discectomy and Fusion With Plating in Trauma Patients: Is It Safe?

This study aimed to evaluate the safety and necessity of tracheostomy after anterior cervical discectomy and fusion (ACDF) with plating, despite the close proximity of the two surgical skin incisions. Sixty-three patients with traumatic cervical fractures or spinal cord injury (SCI) who underwent single-level ACDF and plating between January 2014 and June 2019 were included in this study. The patients included 45 men and 18 women, with a mean age of 48.5 years. A retrospective analysis of the patients' demographic data, level of injury, radiological findings, and neurological status was performed based on the American Spinal Injury Association (ASIA), open tracheostomy, and decannulation rate. Additionally, risk factors necessitating tracheostomy were statistically analyzed. Eighteen patients (28.5%) required subsequent open tracheostomy. Among them, 11 patients were successfully decannulated, four patients could not be decannulated during the follow-up period, and three patients died of unrelated complications. The median interval from ACDF with plating to open tracheostomy was 9.6 days (range, 5-23 days). On the basis of neurological status, ASIA A and B patients (p<0.001), high signal intensity on T2-weighted-magnetic resonance (MR) images (p=0.001), and major cervical fracture and dislocation were significant risk factors for tracheostomy (p=0.02). No patient showed evidence of significant soft tissue, bony infection, or nonunion during the follow-up period. Independent tracheostomy did not increase the risk of infection or nonunion despite the close proximity of the two surgical skin incisions.

Dysphagia Weakly Correlates With Other Patient-Reported Outcomes After Anterior Cervical Discectomy and Fusion.

IntroductionDysphagia is a common complication after anterior cervical discectomy and fusion (ACDF), but it is not a routinely asked question in legacy patient-reported outcome measures (PROMs). This study analyzes whether there are associations between dysphagia and legacy outcome measures.MethodsWe retrospectively reviewed 168 patients who underwent ACDF surgery from 2017 to 2019 at a single institution. Demographics, anthropometric data, Neck Disability Index (NDI), Visual Analog Scale (VAS)-Arm and VAS-Neck Pain scores, Patient-Reported Outcomes Measurement Information System (PROMIS)-Physical and PROMIS-Mental scores, Charlson Comorbidity Index (CCI), and Eating Assessment Tool-10 (EAT-10) were obtained for each patient preoperatively and at one, three, six, and 12 months postoperatively. Pearson’s correlation coefficients were used to evaluate the bivariate correlations between legacy, PROMIS, and EAT-10 measures.ResultsSignificant but weak correlations existed between NDI and EAT-10 at one, three, and six months postoperatively (correlation coefficient (R) = 0.31, 0.42, and 0.34 at one, three, and six months, p < 0.001) and VAS-Neck Pain and EAT-10 scores at one, three, and six months postoperatively (R = 0.27, 0.30, and 0.28 at one, three, and six months, p ≤ 0.004). Both PROMIS-Physical and PROMIS-Mental scores showed significant but weak correlations with EAT-10 scores at three and six months postoperatively (R = -0.29 and -0.25, p ≤ 0.01, at three months and R = -0.25 and -0.28, p < 0.01, at six months). In all comparisons of EAT-10 scores with legacy outcome measures, the significance of correlations disappeared by 12 months postoperatively. In addition, there was a positive association between CCI and EAT-10 score (β = 0.37, p < 0.05).ConclusionWeak correlations exist between self-reported dysphagia scores and legacy patient-reported outcome measures in patients undergoing ACDF. The correlation strength decreases over time; therefore, dysphagia scores should be reported separately when looking at outcomes after ACDF. Patients with more comorbidities are also at increased risk for dysphagia.

Poorer Preoperative Function Leads to Delayed Return to Work After Anterior Cervical Discectomy and Fusion for Degenerative Cervical Myelopathy.

The factors that affect return to work (RTW) after anterior cervical discectomy and fusion (ACDF) for degenerative cervical myelopathy (DCM) remain unclear, especially in a non-Workers' Compensation setting. We aimed to (1) identify factors that influence RTW in patients undergoing ACDF (2) determine if early RTW plays a role in functional outcomes, quality of life, and satisfaction. Prospectively collected data of 103 working adults who underwent primary ACDF for DCM were retrospectively reviewed. Patients were stratified into 2 groups: early RTW (≤60 days, n = 42) and late RTW (>60 days, n = 61). The mean time taken to RTW was 34.7 and 134.9 days in the early and late RTW groups, respectively (P < 0.001). The early RTW group had significantly better preoperative Japan Orthopaedic Association (JOA) score and Neck Disability Index (NDI) (P < 0.05) and showed a trend toward higher 36-Item Short Form Physical Component Summary (PCS) (P = 0.071). The early RTW group also had significantly better postoperative JOA, NDI, and PCS at 6 months and less arm pain along with a trend toward better NDI at 2 years (P = 0.055). However, there was no difference in the change in outcome scores and a similar proportion in each group attained the minimal clinically important difference for each metric. At 2 years, 85.7% and 77.0% were satisfied in the early and late RTW groups, respectively (P = 0.275). While working adults that RTW later tend to have poorer function preoperatively and up to 2 years postoperatively, surgeons may reassure them that they will likely experience the same degree of clinical improvement and level of satisfaction after ACDF. Level 3, therapeutic study.