Posterior Cervical Spine Surgery Research Articles

Posterior Surgical Techniques for Cervical Spondylotic Myelopathy: WFNS Spine Committee Recommendations.

ObjectiveThis study was conducted to determine and recommend the most up-to-date information on the indications, complications, and outcomes of posterior surgical treatments for cervical spondylotic myelopathy (CSM) on the basis of a literature review. MethodsA comprehensive literature search was performed, using the MEDLINE (PubMed), the Cochrane Register of Controlled Trials, and Web of Science databases, for peer-reviewed articles published in English during the last 10 years. ResultsPosterior techniques, which include laminectomy alone, laminectomy with fusion, and laminoplasty, are often used in patients with involvement of 3 or more levels. Posterior decompression for CSM is effective for improving patients’ neurological function. Complications resulting from posterior cervical spine surgery include injury to the spinal cord and nerve roots, complications related to posterior screw fixation or instrumentation, C5 palsy, spring-back closure of lamina, and postlaminectomy kyphosis. ConclusionIt is necessary to consider multiple factors when deciding on the appropriate operation for a particular patient. Surgeons need to tailor preoperative discussions to ensure that patients are aware of these facts. Further research is needed on the cost-to-benefit analysis of various surgical approaches, the comparative efficacy of surgical approaches using various techniques, and long-term outcomes, as current knowledge is deficient in this regard.

Extensor muscle-preserving laminectomy in treating multilevel cervical spondylotic myelopathy compared with laminoplasty.

Laminectomy and laminoplasty are popularly used in posterior cervical spine surgery but still have involved complications. We aimed to compare the clinical outcomes of microscope-assisted extensor muscle-preserving laminectomy (MA-EMPL) and open-door laminoplasty (ODLP) in treating multilevel cervical spondylotic myelopathy (MCSM). A prospective study was designed to enroll twenty patients with MCSM underwent MA-EMPL, and recruit twenty-four patients with MCSM received ODLP (control). Radiographic measurements, outcome indicators including Japanese Orthopedic Association (JOA) score and visual analogue score (VAS) were used to evaluate technical effectiveness. Surgical complications were documented to assess technical safety. Postoperative cervical curvature index and range of neck motion (ROM) were not significantly changed except ROM in ODLP group. Postoperative JOA score and VAS in both groups showed improvements at final follow-up. There was no statistical difference in postoperative neurological recovery rates between two groups (67.6%±17.8% vs. 70.15%±19.6%, P=0.632). However, VAS was significantly lower at postoperative 1 month in MA-EMPL group compared with ODLP group (P<0.001). The incidences of C5 palsy were 0 vs. 16.7% between MA-EMPL group and ODLP group. There was no axial symptom occurred in MA-EMPL group while six patients in ODLP group (0 vs. 25%, P=0.049). In addition, the mean blood loss and hospital stay were lesser in MA-EMPL group compared with ODLP group (P<0.001, P=0.002, respectively). MA-EMPL is an effective, safe and minimally invasive method in treatment of MCSM. Compared with ODLP, MA-EMPL has advantage to decrease intraoperative blood loss, hospital stay, postoperative VAS and axial symptom, as well as preserve postoperative ROM.

281. C5 palsy and neurological complications after cervical spine surgery

BACKGROUND CONTEXT Neurologic complications of cervical spine surgery include C5 palsy, monoplegia, paraplegia and quadriplegia and can have significant impact on quality of life. C5 palsy has a reported incidence of 0-30% with few well-established risk factors. Postoperative cervical spine iatrogenic monoplegia, paraplegia and quadriplegia have little literature supporting their incidence. The Charlson Comorbidity Index is a measure of comorbidity in patients that is associated with surgical outcomes. PURPOSE The objective of this study was to identify the incidence and risk factors for severe neurological complications including C5 palsy after cervical spine surgery using a nationwide patient database. STUDY DESIGN/SETTING Retrospective database study. PATIENT SAMPLE Patients from the Humana national database who underwent cervical spine surgery between 2007 and 2016. OUTCOME MEASURES Neurological complications, CCI, patient demographics. METHODS The International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9), The International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10), and Current Procedural Terminology (CPT) codes were used to identify and evaluate patients from the Humana national database for neurological complications following posterior fusion cervical spine surgery, anterior fusion cervical spine surgery, laminectomy/laminotomy of the cervical spine, and artificial disc replacement of the cervical spine. Neurological complications were evaluated over a 14-day postoperative period. Using Chi-squared testing, complication incidences and relative risk ratios were calculated with respect to type of cervical spine surgery, CCI, patient age, and patient sex. RESULTS A total of 45,373 patients from the Humana database fit the inclusion criteria for cervical spine surgery. Of these, 732 (1.61%) patients experienced a neurological complication within 14 days after cervical spine surgery. C5 palsy had an incidence of 0.06% across all cervical spine surgeries (29 of 45,373 patients). A CCI >3 had a 5.44 times relative risk for any neurological complication (RR: 5.44; 95% CI: 4.70 - 6.30; p CONCLUSIONS Patients who underwent cervical spine surgery and had a CCI > 3 were at a significantly increased relative risk for neurological complications including C5 palsy within 14 days after surgery. Compared to female patients, male patients had a statistically significant increased incidence in neurological complications, but no significant increase in incidence for C5 palsy. Posterior fusion cervical spine surgery had the highest incidence of neurological complications. Age was correlated with greater incidence of neurological complications. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Skull Clamp Application: A Safe, Team-based Approach and Literature Review

Outcomes in posterior cervical spine surgery are highly dependent on proper operative head and neck positioning. As with any spinal procedure, posterior cervical surgery can be associated with significant morbidity; known complications directly related to positioning include postoperative vision loss, neurological injury, and poor surgical outcome. Unsurprisingly, a variety of techniques have been developed that aim to mitigate these complications while improving overall outcomes. The aim of this article is to present a standardized technique for application of the Mayfield skull clamp focusing on a team-based approach for patient positioning to minimize complications. The existing literature is also reviewed for complications associated with head positioning devices. Our method of clamp application and patient positioning minimizes complications (0.36% over a 14-y period), optimizes surgical exposure with anatomic position of the bony elements, and maximizes intraoperative spinal stability. This protocol is ideal for all the posterior cervical procedures.

Cervical Spinal Cord Injury Associated With Neck Flexion in Posterior Cervical Decompression

A retrospective analysis of prospectively collected data of 179 consecutive patients who underwent intraoperative neurophysiological monitoring during posterior cervical spine surgery for compression myelopathy. To evaluate preoperative factors in patients with deteriorating spinal cord function due to flexion of the neck during posterior cervical spine surgery by observing changes in waveforms on intraoperative monitoring. We encountered several cases of intraoperative monitoring warning alerts because of neck flexion during posterior cervical spine surgery. We investigated the incidence rate and intraoperative predictors of deteriorating spinal cord function caused by neck flexion based on waveform changes. Subjects were 179 patients who underwent posterior cervical decompression for spinal cord compression. When warning alarms were set off by amplitude changes in the period between skin incision and exposure of the lamina, the neck position was changed from flexion to neutral, and patients whose electrical potentials recovered following cervical repositioning were placed in the flexion-induced potential reduction group. We then analyzed and extracted risk factors for flexion-induced reduction in electrical potentials. In total, 156 patients were analyzed in this study. Monitoring alarms went off intraoperatively for 7 patients (4.5%) at the time of posterior cervical spine exposure. With regard to the most compressed level, the occupancy ratio of the anterior compression component, the kyphotic angle in flexion, and range of motion in the neutral position to flexion were significantly associated with flexion-induced reduction in electrical potentials. Furthermore, logistic regression analysis extracted the occupancy ratio of the anterior compression component at the most compressed level and the kyphotic angle of the most compressed level in flexion. Our findings suggest that a large anterior compression component and large kyphotic angle in neck flexion at the most compressed level are risk factors for intraoperative spinal cord injury during posterior cervical spine surgery.

A New Grading of Epidural Hematoma or Scar Formation after Posterior Cervical Spine Surgery: Evaluation of Perioperative Related Factors, Distributions, and Clinical Outcomes after Surgery.

Introduction The purpose of this study was to evaluate surgical outcomes using a new grading of postoperative epidural hematoma (EH) or epidural scar formation after posterior cervical spine surgery. Methods Postoperative EH or epidural scar formation after cervical laminoplasty (LP) or posterior decompression and fusion (PDF) were graded into Grades 1-5 by magnetic resonance imaging at 24 hours, 2 weeks, 6 months, and one year after surgery. The patients were divided into the Mild group (Grades 1-3) and the Severe group (Grades 4, 5). Perioperative factors were compared between the two groups at 24 hours after surgery. Distribution of EH or scar formation was investigated according to two surgeries. The recovery rate of Japanese Orthopedic Association (JOA) scores and the improvements of neck disability index (NDI) were compared between the two groups at one year postoperatively. Results Of the postoperative factors, posterior shift of the cervical spinal cord at C4 and C7 significantly differed between the two groups. Patients in the Severe group at 24 hours after surgery (17%) increased to 41% at 2 weeks and subsequently decreased to 16% at 6 months after LP. After PDF, 3% in the Severe group at 24 hours after surgery increased to 15% at 2 weeks and then decreased to 3% at 6 months postoperatively. Only one (3%) patient remained in the Severe group at 1 year after PDF. The recovery rate of JOA score (47.5%) of the patients in the Mild group showed trend larger than that of the Severe group (34.7%) after LP. Preoperative NDI (15.6 points) significantly improved postoperatively to 12.1 points in only the Mild group after LP. Conclusions The patterns of distribution of EH or scar formation did not differ between the two surgical methods. The severity of postoperative scar formation related to surgical outcomes after LP.

Prone Positioning of Patients with Cervical Spine Pathology

AbstractPatients with cervical trauma or degenerative disease often require surgical decompression and stabilization in the prone position and are at the risk of secondary neurological injury during this transfer. This review aims to explore the current literature on different methods of positioning patients prone and to identify the safest technique to achieve prone positioning in patients with an unstable cervical spine undergoing posterior cervical spine surgery. We searched the Embase, Medline, and Medline-in Process databases for literature in English related to prone positioning patients with cervical spine pathology undergoing spine surgery. Seventy-three citations were identified as relevant and reviewed in detail with 20 articles being identified as answering the clinical questions posed. Our literature review identified three methods of prone positioning patients with cervical pathology: logroll with manual in-line stabilization (MILS), rotating the patient on a specialized spinal table using a “sandwich and flip” technique, and awake prone positioning. Each of these methods has its own advantages and disadvantages. When comparing the degree of neck movement between positioning techniques, “sandwich and flip” rotation was associated with over 50% reduction in both flexion–extension and axial–lateral rotation as compared to logroll with MILS. Awake self-positioning of a patient is another alternative that allows for rapid neurological assessment after repositioning. A “sandwich and flip” is the safest way to turn a patient with cervical pathology into a prone position for surgery. For cooperative patients, who are physically capable, awake self-positioning is a good alternative.

The Impact of Metabolic Syndrome on 30-Day Outcomes Following Elective Anterior Cervical Discectomy and Fusions.

Retrospective review of prospective registry OBJECTIVE.: To analyze the impact of metabolic syndrome (MetS) on 30-day outcomes following elective anterior cervical discectomy and fusions (ACDFs). MetS is defined as the presence of a combination of hypertension, diabetes mellitus, and obesity. Past literature has reported MetS to complicate postoperative care in patients undergoing various surgical procedures, including lumbar fusions. The 2015 to 2016 American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) database was queried using current procedural terminology (CPT) codes 22,551 (single-level) and 22,552 (additional level). Patients undergoing disc arthroplasty, multi-level (>3) fusion, posterior cervical spine surgery, and patients with fracture, tumor, infection were excluded. MetS was defined using a pre-set criteria used by other NSQIP studies as the presence of-(1) diabetes mellitus, (2) hypertension requiring medication, and (3) body mass index (BMI) more than or equal to 30 kg/m. A total of 1384 (8.8%) patients with MetS underwent a cervical fusion. Following adjusted analysis, results showed that presence of MetS was associated with higher odds of a prolonged length of stay more than or equal to 3 days (odds ratios [OR] 1.32 [95% confidence interval [CI] 1.12-1.56]; P = 0.001). No significant association was found between MetS and 30-day complications, 30-day reoperations, 30-day re-admissions, a non-home discharge, and death. While MetS was associated with a prolonged length of stay, its presence does not have a large impact on 30-day outcomes following elective ACDF. 3.

The relationship between surgical site drains and reoperation for wound-related complications following posterior cervical spine surgery: a multicenter retrospective study.

OBJECTIVEUse of surgical site drains following posterior cervical spine surgery is variable, and its impact on outcomes remains controversial. Studies of drain use in the lumbar spine have suggested that drains are not associated with reduction of reoperations for wound infection or hematoma. There is a paucity of studies examining this relationship in the cervical spine, where hematomas and infections can have severe consequences. This study aims to examine the relationship between surgical site drains and reoperation for wound-related complications following posterior cervical spine surgery.METHODSThis study is a multicenter retrospective review of 1799 consecutive patients who underwent posterior cervical decompression with instrumentation at 4 tertiary care centers between 2004 and 2016. Demographic and perioperative data were analyzed for associations with drain placement and return to the operating room.RESULTSOf 1799 patients, 1180 (65.6%) had a drain placed. Multivariate logistic regression analysis identified history of diabetes (OR 1.37, p = 0.03) and total number of levels operated (OR 1.32, p < 0.001) as independent predictors of drain placement. Rates of reoperation for any surgical site complication were not different between the drain and no-drain groups (4.07% vs 3.88%, p = 0.85). Similarly, rates of reoperation for surgical site infection (1.61% vs 2.58%, p = 0.16) and hematoma (0.68% vs 0.48%, p = 0.62) were not different between the drain and no-drain groups. However, after adjusting for history of diabetes and the number of operative levels, patients with drains had significantly lower odds of returning to the operating room for surgical site infection (OR 0.48, p = 0.04) but not for hematoma (OR 1.22, p = 0.77).CONCLUSIONSThis large study characterizes current practice patterns in the utilization of surgical site drains during posterior cervical decompression and instrumentation. Patients with drains placed did not have lower odds of returning to the operating room for postoperative hematoma. However, the authors' data suggest that patients with drains may be less likely to return to the operating room for surgical site infection, although the absolute number of infections in the entire population was small, limiting the analysis.

What is a Right Distal Fusion Level for Prevention of Sagittal Imbalance in Multilevel Posterior Cervical Spine Surgery: C7 or T1?

This was a retrospective cohort study. To evaluate the sagittal alignment and T1 slope after multilevel posterior cervical fusion surgery depending on the distal fusion level; C7 or T1, and find out the appropriate distal fusion level. The sagittal balance of the cervical spine is known to be affected by cervical lordosis and T1 slope. However, T1 slope is not a constant parameter that can be frequently changed after the surgery. Furthermore, useful studies to help guide surgeons in decision-making as to the most appropriate distal level of fusion for cervical sagittal balance are very limited. From 2014 to 2015, 50 patients who underwent multilevel posterior cervical fusion surgery were evaluated and followed up for >2 years. Group 1 was composed of 29 patients whose distal fusion level was C7. Group 2 was composed of 21 patients whose distal fusion level was T1. C1-C2 lordosis, C2-C7 lordosis, C2-C7 sagittal vertical axis (SVA), and T1 slope were measured on preoperative and the last follow-up. In group 1, C2-C7 SVA (23.1→30.4 mm, P=0.043) was worsened, and T1 slope (22.3→32.9 degrees, P=0.001) was increased after the surgery. In group 2, no significant change occurred in C2-C7 SVA after the surgery (25.3 →23.6 mm, P=0.648). The last follow-up T1 slope was similar with preoperative T1 slope (22.7→21.8 degrees, P=0.04) in group 2. This study showed that sagittal alignment became worse after the multilevel posterior cervical surgery when distal fusion level was stopped at C7, which was associated with increase of T1 slope. However, when we extended the distal fusion level to T1, T1 slope was not changed after the surgery. Therefore, sagittal alignment was maintained after the surgery. On the basis of the results of this study, we recommend distal fusion extends to T1. Level III.

Body mass index and the risk of deep surgical site infection following posterior cervical instrumented fusion

BACKGROUNDSurgical site infection (SSI) following spine surgery is associated with increased morbidity, reoperation rates, hospital readmissions, and cost. The incidence of SSI following posterior cervical spine surgery is higher than anterior cervical spine surgery, with rates from 4.5% to 18%. It is well documented that higher body mass index (BMI) is associated with increased risk of SSI after spine surgery. There are only a few studies that examine the correlation of BMI and SSI after posterior cervical instrumented fusion (PCIF) using national databases, however, none that compare trauma and nontraumatic patients. PURPOSEThe purpose of this study is to determine the odds of developing SSI with increasing BMI after PCIF, and to determine the risk of SSI in both trauma and nontraumatic adult patients. STUDY DESIGNThis is a retrospective cohort study of a prospective surgical database collected at one academic institution. PATIENT SAMPLEThe patient sample is from a prospectively collected surgical registry from one institution, which includes patients who underwent PCIF from April 2011 to October 2017. OUTCOME MEASURESA SSI that required return to the operating room for surgical debridement. METHODSThis is a retrospective cohort study using a prospectively collected database of all spine surgeries performed at our institution from April 2011 to October 2017. We identified 1,406 patients, who underwent PCIF for both traumatic injuries and nontraumatic pathologies using International Classification of Diseases 9 and 10 procedural codes. Thirty-day readmission data were obtained. Patient's demographics, BMI, presence of diabetes, preoperative diagnosis, and surgical procedures performed were identified. Using logistic regression analysis, the risk of SSI associated with every one-unit increase in BMI was determined. This study received no funding. All the authors in this study report no conflict of interests relevant to this study. RESULTSOf the 1,406 patients identified, 1,143 met our inclusion criteria. Of those patients, 688 had PCIF for traumatic injuries and 454 for nontraumatic pathologies. The incidence of SSI for all patients, who underwent PCIF was 3.9%. There was no significant difference in the rate of SSI between our trauma group and nontraumatic group. There was a higher rate of infection in patients, who were diabetic and with BMI≥30 kg/m2. The presence of both diabetes and BMI≥30 kg/m2 had an added effect on the risk of developing SSI in all patients, who underwent PCIF. Additionally, logistic regression analysis showed that there was a positive difference measure between BMI and SSI. Our results demonstrate that for one-unit increase in BMI, the odds of having a SSI is 1.048 (95% CI: 1.007–1.092, p=.023). CONCLUSIONSOur study demonstrates that our rate of SSI after PCIF is within the range of what is cited in the literature. Interestingly, we did not see a statistically significant difference in the rate of infection between our trauma and nontrauma group. Overall, diabetes and elevated BMI are associated with increased risk of SSI in all patients, who underwent PCIF with even a higher risk in patient, who are both diabetic and obese. Obese patients should be counseled on elevated SSI risk after PCIF, and those with diabetes should be medically optimized before and after surgery when possible to minimize SSI.

Optimizing Patient Access During an Emergency While Using Intraoperative Computed Tomography

As minimally invasive spine surgery evolves, spine surgeons increasingly rely on advanced intraoperative computed tomography (iCT). iCT provides rapid acquisition of high-resolution images, reduces radiation exposure, improves surgical accuracy, and decreases operative time. However, all iCT systems currently available pose a patient safety risk as their physical space requirements limit patient access in the event of an emergency, particularly when patients are in the prone position. After a near-cardiac arrest at our institution during posterior cervical spine surgery, it was apparent that the presence of the iCT complicated the ability to rapidly reposition the patient in order to provide appropriate resuscitation. To ensure our ability to provide timely care during an emergency, we determined that a process which included all members of the operating room (OR) team was required. We held an initial planning meeting where a detailed plan-of-action was created, reviewed, and revised in response to feedback from all stakeholders. We then simulated a cardiac arrest to test our resuscitation plan with all members of the neurosurgery team. A mannequin was positioned prone on an OR table within the iCT, and a resuscitation plan was created. The team orchestrated the mock resuscitation, and the time of cardiac arrest in the prone position to supine repositioning required 110 seconds. The simulation was recorded for post-"code" performance review. Application of the protocol during an actual cardiac arrest was associated with successful restoration of spontaneous circulation and full recovery. The development and rehearsal of an emergency plan of action greatly facilitated the timely responsiveness of the neurosurgical OR team during a simulated cardiac arrest and was an effective way to identify and address key logistical issues regarding the use of an iCT system.

Chronic Obstructive Pulmonary Disease Is an Independent Predictor for 30-Day Complications and Readmissions Following 1- to 2-Level Anterior Cervical Discectomy and Fusion.

Study Design:Retrospective cohort.Objectives:To study evidence to assess the impact of chronic obstructive pulmonary disease (COPD) on 30-day outcomes following 1- to 2-level anterior cervical discectomy and fusion (ACDF).Methods:The 2015-2016 American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) database was queried using Current Procedural Terminology (CPT) codes 22 551 (single-level) and 22 552 (additional level). Patients undergoing disc arthroplasty, multilevel (>2) fusion, posterior cervical spine surgery, and patients with fracture, tumor, and/or infection were excluded.Results:Out of 14 835 patients undergoing an elective 1- to 2-level ACDF, 649 (4.4%) had a diagnosis of COPD at the time of the surgery. Following adjusted logistic regression analysis, prior history of COPD was significantly associated with a longer length of stay (odds ratio [OR] 1.25 [95% confidence interval (CI0 1.04-1.52]; P = .019), superficial surgical site infection (OR 2.68 [95% CI 1.06-6.80]; P = .038), discharge destination other than home (OR 1.49 [95% CI 1.05-2.12]; P = .026), pneumonia (OR 4.37 [95% CI 2.42-7.88]; P < .001), ventilator use >48 hours (OR 5.34 [95% CI 1.88-15.15]; P = .002), unplanned reintubation (OR 3.36 [1.48-7.62]; P = .004), and 30-day readmissions (OR 1.69 [95% CI 1.20-2.38]; P = .003).Conclusions:The findings of this study show that COPD patients are more likely to have postoperative complications and 30-day readmissions, despite elective ACDF itself being a low-risk surgery in general. Results show that majority of the complications were pulmonary in nature, further stressing the need for accurate medical optimization following surgery in these patients.

Discharge to skilled-care or rehabilitation following elective anterior cervical discectomy and fusion increases the risk of 30-day re-admissions and post-discharge complications.

With a shift toward value-based and bundled-payment models, identification of areas of cost and quality improvement will be required. Though abundant literature is present on the predictors of discharge destinations, few studies have studied the impact of discharge to a skilled-care or rehabilitation facility on post-discharge outcomes following elective spine surgery. The 2015-2016 ACS-NSQIP database was queried using Current Procedural Terminology (CPT) codes 22551 and 22552 to retrieve records of patients undergoing ACDF (≤3 levels). Patients who had concurrent posterior cervical spine procedures and surgery for malignancy and spinal deformity were excluded. A total of 15,624 patients were finally included for analysis, 459 (2.9%) patients were discharged to a skilled care or rehabilitation facility. Age of ≥65 years, Black or African-American race, partially dependent or totally dependent functional health status, a LOS ≥3 days, a total operative time >150 min, ASA grade > II and inpatient surgery were significant predictors for a discharge to skilled care/rehabilitation facility. Following adjustment for pre-discharge clinical characteristics, discharge to skilled care or rehabilitation was an independent significant risk factor for renal complications (OR =8.22; 95% CI, 1.84-36.7; P=0.006) and 30-day readmissions (OR =1.63; 95% CI, 1.09-2.42; P=0.016). Discharge to skilled-care or rehabilitation facilities following elective ACDF is associated with higher odds of renal complications and 30-day readmissions. These results stress the importance of careful patient selection prior to discharge to inpatient care facilities to minimize the risk of complications.

Dependent functional status is associated with unplanned postoperative intubation after elective cervical spine surgery: a national registry analysis.

The impact of preoperative functional status on 30-day unplanned postoperative intubation and clinical outcomes among patients who underwent cervical spine surgery is not well-described. We hypothesized that functional dependence is associated with 30-day unplanned postoperative intubation and that among the reintubated cohort, functional dependence is associated with adverse postoperative clinical outcomes after cervical spine surgery. Utilizing the 2007-2016 American College of Surgeons National Surgical Quality Improvement Program database, we identified adult elective anterior and posterior cervical spine surgery patients by CurrentProcedural Terminology codes. We performed (1) a Cox Proportional Hazard analysis for the following outcomes: reintubation, prolonged ventilator use, and pneumonia and (2) an adjusted logistic regression analysis among patients that required postoperative reintubation to evaluate the association of functional status with adverse postoperative outcomes. The sample size was 26,263, of which 550 (2.1%) were functionally dependent. The adjusted model suggested that when compared with functionally independent patients, dependent patients were at increased risk of unplanned 30-day intubation (HR 2.05, 95% CI 1.26-3.34; P = 0.003). The adjusted risk of 30-day postoperative pneumonia was significantly higher in patients with functional dependence (HR 1.61, 95% CI 1.02-2.54, P = 0.036). Among patients that required postoperative reintubation, the odds of 30-day mortality was significantly higher in patients with functional dependence (OR 5.82, 95% CI 1.59-23.4, P < 0.001). Preoperative functional dependence is a good marker for estimating postoperative unplanned intubation following cervical spine surgery.

The Role of C2-C7 Angle in the Development of Dysphagia After Anterior and Posterior Cervical Spine Surgery.

This is a retrospective clinical study. To analyze the relationship between cervical alignment and the development of dysphagia after anterior and posterior cervical (PC) spine surgery [anterior cervical discectomy and fusion (ACDF), cervical disk replacement (CDR), and PC]. Dysphagia is a known complication of cervical surgery and may be prolonged or occasionally serious. A previous study showed dysphagia after occipitocervical fusion was caused by oropharyneal stenosis resulting from O-C2 (upper cervical lordosis) fixation in a flexed position. However, there have been few reports analyzing the association between the C2-C7 angle (middle-lower cervical lordosis) and postoperative dysphagia. In total, 452 patients were reviewed in this study, including 172 patients who underwent the ACDF procedure, 98 patients who had the CDR procedure, and 182 patients who had the PC procedure between June 2007 and May 2010. The presence and duration of postoperative dysphagia were recorded via face-to-face questioning or telephone interview performed at least 1 year after the procedure. Plain cervical radiographs before and after surgery were collected. The O-C2 angle and C2-C7 angle were measured. The change of O-C2 angle and C2-C7 angle were defined as dO-C2 angle=postoperative O-C2 angle-preoperative O-C2 angle and dC2-C7 angle=postoperative C2-C7 angle-preoperative C2-C7 angle. The association between postoperative dysphagia with dO-C2 angle and dC2-C7 angle was studied. A total of 12.8% ACDF, 5.1% CDR, and 9.4% PC patients reported dysphagia after cervical surgery. The dC2-C7 angle has considerable impact on postoperative dysphagia. When dC2-C7 angle is >5 degrees, the chance of developing postoperative dysphagia of this patient is significantly greater. The dO-C2 angle, age, sex, body mass index, operative time, blood loss, procedure type, revision surgery, most cephalic operative level, and number of operative levels did not significantly influence the incidence of postoperative dysphagia. No relationship was found between the dC2-C7 angle and the degree of dysphagia. Postoperative dysphagia is common after cervical surgery. The dC2-C7 angle may play an important role in the development of dysphagia in both anterior and PC spine surgery. Overenlargement of cervical lordosis should be avoided to reduce the development of postoperative dysphagia.

Swallowing Physiology after Anterior and Posterior Cervical Spine Surgery: A Comparison on Videofluoroscopy Pre- and Post-surgery

Dysphagia is a common complication following anterior cervical spine surgery and may occur in over 70% of patients. There is an emerging evidence that dysphagia also appears after posterior cervical spine surgery. Nevertheless, hardly any study is focusing on changes in swallowing physiology with regard to surgical approach. Aim of this study: To investigate changes in swallowing physiology following: 1. anterior cervical spine surgery, and 2. posterior cervical spine surgery. Methods: A standardized videofluoroscopic swallowing study (VFSS) was performed in 28 patients who underwent cervical spine surgery (anterior approach n = 19, Mage 56±14; posterior approach n = 9, Mage 58±17) one day before surgery and after surgery (mean 4 days). Data were analyzed retrospectively with the Modified Barium Swallow Impairment Profile (MBSImPTM©). Results: 1. In the anterior group, pharyngeal sum score was significantly higher after surgery (p < .001). Significant changes were found in 4 out of 8 analyzed pharyngeal components. 2. In the posterior group, pharyngeal sum score was significantly higher after surgery (p = .015). No significant changes were found in the oral or pharyngeal components. Conclusions: Whereas more changes in swallowing physiology occurred following anterior surgery, there were also overall changes in the posterior group. Understanding the swallowing pathophysiology associated with cervical spine surgery is indispensable to decrease the rate of secondary complications and improve quality of life for this patients.

National Rates, Causes, Risk Factors, and Outcomes Associated With 30-Day and 90-Day Readmissions Following Degenerative Posterior Cervical Spine Surgery Utilizing the Nationwide Readmissions Database.

Hospital readmissions have profound financial and clinical impacts. Analyses of 30-day readmissions following spine surgery have been previously reported utilizing administrative databases. However, time periods outside the initial 30 days have not been well studied. Furthermore, these databases have limitations regarding coding and institutional crossover. The authors sought to analyze 30-day and 90-day readmission rates and risk factors using the Nationwide Readmissions Database (NRD) in a retrospective cohort receiving elective, posterior cervical spine surgery for degenerative conditions. NRD is a new source containing approximately 50% of US hospitalizations, with patient-linkage numbers to longitudinally track patients. Patients 18 years of age or older were identified. Preoperative characteristics, demographics, and surgical characteristics were chosen for predictor variables. Thirty-day and 90-day readmission rates were calculated. Statistical analysis was completed using SPSS v.23 software via univariate and multivariate analyses. Between January and September 2013, a total of 29 990 patients were identified. Readmission rates for 30- and 90-days were 5.4% and 10.0%, respectively. The most common reason for readmission during 30-day and 90-day periods was complications of surgical and/or medical care (31.0% vs 21.9%, respectively). The strongest risk factors for 30-day readmission included wound dehiscence, weekend admission at index hospitalization, coagulopathy, and incidental durotomy. The strongest risk factors for 90-day readmission included thromboembolic complications, postoperative hemorrhage, and comorbidities. Identification of predictors of readmission is important to allow for changes in perioperative management to potentially reduce readmissions and improve outcomes. Additionally, knowledge about readmission risk factors allows for preoperative counseling.

244 - Axial Neck Pain following Posterior Cervical Spine Surgery: Laminoplasty vs Laminectomy and Fusion

244 - Axial Neck Pain following Posterior Cervical Spine Surgery: Laminoplasty vs Laminectomy and Fusion

P151 - National Rates, Causes, Risk Factors and Outcomes Associated with 30-Day and 90-Day Readmissions Following Degenerative Posterior Cervical Spine Surgery Utilizing the Nationwide Readmissions Database

BACKGROUND CONTEXT: Hospital readmissions have profound financial and clinical impacts. Analyses of 30-day readmissions following spine surgery have been previously reported utilizing administrative databases. However, time periods outside the initial 30 days have not been well studied. Furthermore, these databases have limitations regarding coding and institutional crossover.