Degenerative Cervical Spine Surgery Research Articles

Factors associated with increased length of stay in degenerative cervical spine surgery: a cohort analysis from the Canadian Spine Outcomes and Research Network.

Postoperative length of stay (LOS) significantly contributes to healthcare costs and resource utilization. The primary goal of this study was to identify patient, clinical, surgical, and institutional variables that influence LOS after elective surgery for degenerative conditions of the cervical spine. The secondary objectives were to examine the variability in LOS and institutional practices used to decrease LOS. This was a multicenter observational retrospective cohort study of patients enrolled in the Canadian Spine Outcomes and Research Network (CSORN) between January 2015 and October 2020 who underwent elective anterior cervical discectomy and fusion (ACDF) (1-3 levels) or posterior cervical fusion (PCF) (between C2 and T2) with/without decompression for degenerative conditions of the cervical spine. Prolonged LOS was defined as LOS greater than the median for the ACDF and PCF populations. The principal investigators at each participating CSORN healthcare institution completed a survey to capture institutional practices implemented to reduce postoperative LOS. In total, 1228 patients were included (729 ACDF and 499 PCF patients). The median (IQR) LOS for ACDF and PCF were 1.0 (1.0) day and 5.0 (4.0) days, respectively. Predictors of prolonged LOS after ACDF were female sex, myelopathy diagnosis, lower baseline SF-12 mental component summary score, multilevel ACDF, and perioperative adverse events (AEs) (p < 0.05). Predictors of prolonged LOS after PCF were nonsmoking status, education less than high school, lower baseline numeric rating scale score for neck pain and EQ5D score, higher baseline Neck Disability Index score, and perioperative AEs (p < 0.05). Myelopathy did not significantly predict prolonged LOS within the PCF cohort after multivariate analysis. Of the 8 institutions (57.1%) with an enhanced recovery after surgery (ERAS) protocol or standardized protocol, only 3 reported using an ERAS protocol specific to patients undergoing ACDF or PCF. Patient and clinical factors predictive of prolonged LOS after ACDF and PCF are highly variable, warranting individual consideration for possible mitigation. Perioperative AEs remained a consistent independent predictor of prolonged LOS in both cohorts, highlighting the importance of preventing intra- and postoperative complications.

Impact of occupational characteristics on return to work for employed patients after elective cervical spine surgery.

In a cohort of employed patients undergoing elective cervical spine surgery with an uncomplicated postoperative course, the authors sought to determine the demographic, functional, and occupational characteristics associated with return to work (RTW) following surgery. A retrospective cohort study of prospectively collected data was undertaken of patients undergoing elective cervical spine surgery for degenerative disease in the Quality Outcomes Database. Study inclusion criteria were: 1) employed prior to surgery and planned to RTW, 2) no unplanned readmissions, 3) achieved 30% improvement on the Neck Disability Index (NDI), and 4) were satisfied with the surgical outcome at 3 or 12 months postoperatively. A multivariable Cox regression model was built using demographic, functional, operative, and occupational characteristic to predict time to RTW. Of 5110 included patients, 4788 (93.7%) returned to work within 12 months, with a median time of 35 (IQR 19-60) days. Patients who did RTW were significantly younger (51.3 ± 9.4 vs 55.8 ± 9.6 years, p < 0.001), more often underwent an anterior approach (85.8% vs 80.7%, p = 0.009), were significantly more privately insured (82.1% vs 64.0%, p < 0.001), and were less likely to have workers' disability insurance (6.7% vs 14.6%, p < 0.001) compared with patients who did not RTW. On multivariable Cox regression, demographic factors associated with a longer RTW were older age (hazard ratio [HR] 0.99, 95% CI 0.99-1.00, p < 0.001) and Black race (HR 0.71, 95% CI 0.62-0.81, p < 0.001). Male sex was associated with a shorter RTW time (HR 1.19, 95% CI 1.11-1.26, p < 0.001). Regarding baseline functional status, worse preoperative NDI (HR 0.99, 95% CI 0.99-0.99, p < 0.001) was associated with a longer RTW, whereas the absence of myelopathy was associated with a shorter RTW (HR 1.17, 95% CI 1.09-1.25, p < 0.001). Having a sedentary (HR 1.81, 95% CI 1.65-1.99, p < 0.001), light-intensity (HR 1.60, 95% CI 1.45-1.76, p < 0.001), and medium-intensity (HR 1.11, 95% CI 1.01-1.22, p = 0.037) occupation was associated with a shorter RTW time compared with a heavy-intensity occupation at any time point. Heavy-intensity occupations were independently the strongest predictor of longer RTW. Similar predictors of shorter RTW were found in a subanalysis of occupation intensity and among operative approaches used. Among patients undergoing elective degenerative cervical spine surgery who had favorable surgical outcomes and planned to RTW before surgery, 94% had a successful RTW. Age was the strongest predictor of lower odds of RTW. Regarding time to RTW, having a sedentary, light-intensity, or medium-intensity occupation was associated with a shorter RTW time compared with a heavy-intensity occupation. These findings highlight the importance of considering the demographic and occupational characteristics when predicting postoperative RTW in patients with satisfactory surgical outcomes.

Temporal analysis of complication rates of cervical spine surgery for degenerative spine disease between younger and older cohorts using the CSORN registry: Is age just a number?

An ambispective review of consecutive cervical spine surgery patients enrolled in the Canadian Spine Outcomes and Research Network (CSORN) between January 2015 and September 2019. To compare complication rates of degenerative cervical spine surgery over time between older (> 65) and younger age groups (< 65). More elderly people are having spinal surgery. Few studies have examined the temporal nature of complications of cervical spine surgery by patient age groups. Adverse events were collected prospectively using adverse event forms. Binary logistic regression analysis was utilized to assess associations between risk modifiers and adverse events at the intra-, peri-operative and 3 months post-surgery. Of the 761 patients studied (age < 65, n = 581 (76.3%) and 65 + n = 180 (23.7%), the intra-op adverse events were not significantly different; < 65 = 19 (3.3%) vs 65 + = 11 (6.1%), p < 0.087. Peri-operatively, the < 65 group had significantly lower percentage of adverse events (65yrs (11.2%) vs. 65 + = (26.1%), p < 0.001). There were no differences in rates of adverse events at 3months post-surgery (< 65 = 39 (6.7%) vs. 65 + = 12 (6.7%), p < 0.983). Less blood loss (OR = 0.99, p < 0.010) and shorter length of hospital stay (OR = 0.97, p < 0.025) were associated with not having intra-op adverse events. Peri-operatively, > 1 operated level (OR = 1.77, p < 0.041), shorter length of hospital stay (OR = 0.86, p < 0.001) and being younger than 65years (OR = 2.11, p < 0.006) were associated with not having adverse events. Following degenerative cervical spine surgery, the older and younger age groups had significantly different complication rates at peri-operative time points, and the intra-operative and 3-month post-operative complication rates were similar in the groups.

NDI

Retrospective review of prospectively collected data. To determine the Neck Disability Index (NDI) cut-off for achieving patient acceptable symptom state (PASS) at six months following degenerative cervical spine surgery. An absolute score denoting PASS might be a better marker to assess clinical outcomes than a change score denoting minimal clinically important difference. Patients who underwent primary anterior cervical decompression and fusion, cervical disk replacement, or laminectomy were included. The outcome measure was NDI. The anchor used to assess PASS achievement at six months was the response on the Global Rating Change: "Compared with preoperative, you feel (1) much better, (2) slightly better, (3) same, (4) slightly worse, or (5) much worse." It was converted to a dichotomous outcome variable (acceptable=response of 1 or 2, unacceptable=response of 3, 4, or 5) for analyses. The overall cohort and subgroups based on age (65yr and below, above 65yr), sex, myelopathy, and preoperative NDI (≤40, >40) were analyzed for the proportion of patients achieving PASS and the NDI cut-off using receiver operator curve. Seventy-five patients (42 anterior cervical decompression and fusion, 23 cervical disc replacement, 10 laminectomy) were included. 79% of patients achieved PASS. Males, patients with age 65 years and below, preoperative NDI ≤40, and absence of myelopathy were more likely to achieve PASS. The receiver operator curve analysis revealed an Oswestry Disability Index cut-off of 21 to achieve PASS (area under the curve, AUC: 0.829, sensitivity: 81%, specificity: 80%). The subgroup analyses based on age, sex, myelopathy, and preoperative NDI revealed AUCs >0.7 and NDI threshold values consistent between 17 and 23. With an AUC of 0.829, NDI showed an excellent discriminative ability. Patients with NDI ≤21 are expected to achieve PASS following degenerative cervical spine surgery.

Is routine blood typing and screening necessary for degenerative cervical spine surgery patients in specialty surgical hospitals?

Blood loss warranting transfusion is a relatively rare requirement for degenerative cervical spine surgery. Despite this rarity, pretransfusion testing (blood typing, screening, and cross-matching) has become routine in most parts of the world. We sought to determine if such routine testing is necessary for patients who undergo degenerative cervical spine surgery patients in specialty surgical hospitals by (1) measuring the current rate of intraoperative transfusions in degenerative cervical spine surgery and (2) identifying risk factors for transfusions. Retrospective review was performed on patients who underwent degenerative cervical spine surgery in two institutions. Demographic and baseline clinical and laboratory data were collected and analyzed to identify predictors of transfusion. Bivariate and multivariate logistic regression analysis was performed to identify perioperative transfusion risk factors. Overall transfusion rate was 1.9% (7/372), with no emergent transfusions. Decreases between preoperative and postoperative hemoglobin and hematocrit were 1.4 (SD 1.1) g/dL and 7.2 (SD 4.1) %, respectively. Multivariate logistic regression identified preoperative Hgb lower than 12 gr/dl (OR 27.62; 95% CI 4.31-176.96; p < 0.001) as significant independent transfusion risk factor. The receiver operating characteristic (ROC) curve for the model showed a very good discriminatory power with an area under the curve of 0.91. Our study suggests that pretransfusion testing for all patients undergoing degenerative cervical spine surgery is unnecessary. We recommend that only patients with preoperative Hgb lower than 12 gr/dl would routinely need pretransfusion testing.

2021 Canadian Spine Society Abstracts.

# Abstract 45. Determining clinically important improvement following surgery for degenerative conditions of the spine: analysis of the Canadian Spine Outcomes and Research Network (CSORN) Registry {#article-title-2} There is significant variability in clinically important improvement (CII)

Intraoperative Neuromonitoring Use Patterns in Degenerative, Nondeformity Cervical Spine Surgery: A Survey of the Cervical Spine Research Society.

A cross-sectional survey study. To determine the neuromonitoring (NM) usage patterns among cervical spine surgeons when performing degenerative, nondeformity cervical spine surgery. Intraoperative NM is frequently used in spine surgery. Although there is literature to support the use of NM in deformity surgery, its utility in degenerative cervical spine surgery remains unclear. A survey was distributed to members of the Cervical Spine Research Society to assess practice patterns of NM use during degenerative cervical spine surgery. The survey consisted of 17 multiple choice questions. The first 3 questions focus on practice experience. The remaining 14 questions pertain to NM practice patterns in the setting of radiculopathy and myelopathy. Significantly more surgeons routinely (>75% of the time) used NM for myelopathy versus radiculopathy (64% vs. 38%, P<0.001). Private practitioners were overall more likely to use NM than academicians (55% vs. 28%, P=0.007 for radiculopathy; 75% vs. 57%, P=0.09 for myelopathy). No significant difference in NM usage was found comparing neurosurgeons and orthopedic spine surgeons. The most commonly cited primary reasons for NM usage were prevention of positioning/hypotension-related neurological complications, and medicolegal protection. Routine NM use during degenerative cervical surgery is significantly more common in myelopathy and is thought to be of more value than in radiculopathy. However, the most common reasons for usage were to provide medicolegal cover and to mitigate neurological complications related to positioning/hypotension, rather than to protect against direct surgical events. These findings contrast the prevailing notion that NM is beneficial in reducing complications related to events occurring in the surgical site when performing spinal deformity correction. We believe that these data provide an important baseline for informing best practice guidelines and further study regarding appropriate NM use for degenerative, nondeformity, cervical spine surgery.

Rates and risk factors associated with 90-day readmission following cervical spine fusion surgery: analysis of the Michigan Spine Surgery Improvement Collaborative (MSSIC) registry

BACKGROUND CONTEXTHospital readmission rates are an increasingly important focus. Identifying patients at risk for readmission can help decrease those rates and thus decrease the overall cost of care. PURPOSEWe sought to report the rates and the risk factors associated with 90-day hospital readmission after degenerative cervical spine surgery via either an anterior or posterior approach. STUDY DESIGNRetrospective review of prospectively collected database PATIENT SAMPLEMichigan Spine Surgery Improvement Collaborative (MSSIC) registry OUTCOME MEASURESHospital readmission at 90 days METHODSThe MSSIC registry prospectively enrolls patients undergoing surgery for degenerative cervical spine disease. The registry was queried over a 4-year period to determine patient characteristics and risk factors associated with unplanned readmission at 90 days following degenerative cervical spine fusion surgery through either an anterior or posterior approach. Univariate and multivariate regression modeling was used to compare patient characteristics and odds of readmission. RESULTSOf 3,762 patients who underwent an anterior approach, 202 (5.4%) were readmitted within 90 days. Of 693 patients who underwent a posterior approach, 85 (12.3%) were readmitted within 90 days. Risk factors associated with increased likelihood of readmission after the anterior approach were male sex (odds ratio [OR] 1.56, confidence interval [CI] 1.10–2.20), American Society of Anesthesiologists class >2 (OR 1.70, CI 1.26–2.30), and increased length of stay (OR 1.10, CI 1.03–1.19). Factors associated with decreased likelihood of readmission after the anterior approach were being independently ambulatory preoperatively (OR 0.59, CI 0.46–0.76) and holding private insurance (OR 0.67, CI 0.50–0.90). A history of previous spine surgery was associated with increased risk of readmission after the posterior approach (OR 1.76, CI 1.37–2.25). Pain was the most common single reason cited for readmission after either approach (9% anterior, 13% posterior). After an anterior approach, common surgical reasons for readmission include new radicular findings (8%), dysphagia (6%), and surgical site hematoma (5%), whereas common medical reasons include pneumonia (7%), infection outside the surgical site (6%), and an electrolyte issue. After a posterior approach, common surgical reasons for readmission after 90 days include surgical site infection (8%) and new radicular findings (6%), whereas common medical reasons include infection outside the surgical site (9%), urinary tract infection (8%), and an abdominal issue (8%). CONCLUSIONSAnalysis of a large multicentered, spine-specific database for elective cervical spine fusion surgery demonstrated an unplanned 90-day readmission rate of 5.4% for the anterior approach and 12.3% for the posterior approach. Factors associated with readmission for the anterior approach include male sex, American Society of Anesthesiologists class >2, increased length of stay, holding private insurance, and being ambulatory preoperatively. A history of previous spine surgery was associated with increased odds of readmission after the posterior approach.

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.

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.

Osteoporosis in Cervical Spine Surgery.

Retrospective administrative database analysis. To investigate the effect of osteoporosis (OS) on complications and outcomes in patients undergoing cervical spine surgery. OS is the most prevalent degenerative human bone disease, and spine surgeons will inevitably perform procedures on patients with OS. These patients might present a difficult patient cohort because many fixation techniques depend on bone quality and adequate bone healing--both of which are compromised in OS. The nationwide inpatient sample was queried using the Ninth Revision, Clinical Modification procedural codes for cervical spine procedures and diagnosis codes for degenerative conditions of cervical spine from 2002 to 2011. Patients were separated into two cohorts, those patients with OS and those without OS. Demographics, hospital characteristics, and adjusted complication likelihood were analyzed. Multivariate regression analysis was performed to determine odds of revision surgery in patients with OS. Of all patients undergoing degenerative cervical spine surgery, 2% were identified as having OS (32,557 of a sample of 1,602,129 patients). Osteoporotic patients were more likely to undergo posterior cervical spine fusion when compared with those patients without OS (11.3% vs. 5.4%, P < 0.0001). Moreover, circumferential fusion was performed 3 times more frequently in the osteoporotic cohort. Adjusted complications showed increased odds for postoperative hemorrhage (odds ratio = 1.70, 95% confidence interval = 1.46-1.98, P < 0.0001). Patients with OS stayed in the hospital longer (3.5 vs. 2.5 days, P < 0.0001) and had 30% costlier hospitalizations. Multivariate for revision surgery indicated that osteoporotic patients had significantly increased odds of revision surgery (odds ratio = 1.54, P ≤ 0.0001) when referenced to non-osteoporotic patients undergoing cervical spine surgery. Osteoporotic patients were more likely to undergo revision surgery, have longer hospitalizations, and have higher hospitalization costs, than their non-osteoporotic counterparts. 3.

Prevalence, Comorbidities, and Risk of Perioperative Complications in Human Immunodeficiency Virus-Positive Patients Undergoing Cervical Spine Surgery

Retrospective database analysis. To evaluate outcomes of human immunodeficiency virus (HIV) positive patients after cervical spine surgery. Highly active antiretroviral medications have qualitatively altered the natural history of HIV, thus increasing the number of HIV-positive patients seeking treatment for chronic degenerative conditions. Minimal data exist on HIV patients undergoing degenerative cervical spine surgery. The Nationwide Inpatient Sample was examined from 2002 to 2011. Hospitalizations were identified using International Classification of Diseases Ninth Revision, Clinical Modification (ICD-9-CM) procedural codes for cervical spine surgery and diagnoses codes for degenerative conditions of the cervical spine, and HIV. Statistical analysis was conducted to evaluate associations between HIV status and perioperative complications. A total of 1,602,129 patients underwent degenerative cervical spine surgery, of which 3700 patients (0.23%) had HIV. The prevalence of HIV increased over the study period from 0.19% to 0.33% (P < 0.001). Patients with HIV were younger (48.6 yrs vs. 53.4 yrs, P < 0.001) and more likely to be male (P < 0.001). HIV patients had significantly greater odds of having chronic pulmonary disease, liver disease, and drug abuse. Unadjusted analysis did not reveal increased rate of acute complications among HIV-positive patients compared with negative controls (3.8% vs. 3.7%, P = 0.62). Multivariate analysis did not identify HIV as a significant predictor of complication (odds ratio = 1.04, P = 0.84). HIV was associated with a 1.5 day increased length of stay AND 1.29 fold increase in median costs compared with controls ($14,551 vs. 18,846, P < 0.001). The prevalence of HIV patients undergoing degenerative cervical spine surgery is increasing. A diagnosis of HIV was not associated with an increased risk of perioperative complication among patients undergoing degenerative cervical spine surgery. Further clinical studies are needed to evaluate predictors of complications among HIV patients and long-term outcomes. 4.

The Burden of Clostridium difficile after Cervical Spine Surgery.

Study Design Retrospective database analysis. Objective The purpose of this study is to investigate incidence, comorbidities, and impact on health care resources of Clostridium difficile infection after cervical spine surgery. Methods A total of 1,602,130 cervical spine surgeries from the Nationwide Inpatient Sample database from 2002 to 2011 were included. Patients were included for study based on International Classification of Diseases Ninth Revision, Clinical Modification procedural codes for cervical spine surgery for degenerative spine diagnoses. Baseline patient characteristics were determined. Multivariable analyses assessed factors associated with increased incidence of C. difficile and risk of mortality. Results Incidence of C. difficile infection in postoperative cervical spine surgery hospitalizations is 0.08%, significantly increased since 2002 (p < 0.0001). The odds of postoperative C. difficile infection were significantly increased in patients with comorbidities such as congestive heart failure, renal failure, and perivascular disease. Circumferential cervical fusion (odds ratio [OR] = 2.93, p < 0.0001) increased the likelihood of developing C. difficile infection after degenerative cervical spine surgery. C. difficile infection after cervical spine surgery results in extended length of stay (p < 0.0001) and increased hospital costs (p < 0.0001). Mortality rate in patients who develop C. difficile after cervical spine surgery is nearly 8% versus 0.19% otherwise (p < 0.0001). Moreover, multivariate analysis revealed C. difficile to be a significant predictor of inpatient mortality (OR = 3.99, p < 0.0001). Conclusions C. difficile increases the risk of in-hospital mortality and costs approximately $6,830,695 per year to manage in patients undergoing elective cervical spine surgery. Patients with comorbidities such as renal failure or congestive heart failure have increased probability of developing infection after surgery. Accepted antibiotic guidelines in this population must be followed to decrease the risk of developing postoperative C. difficile colitis.

Current Trends in the Use of Patient-Reported Outcome Instruments in Degenerative Cervical Spine Surgery.

Study Design Bibliometric analysis. Objective To determine trends, frequency, and distribution of patient-reported outcome instruments (PROIs) in degenerative cervical spine surgery literature over the past decade. Methods A search was conducted via PubMed from 2004 to 2013 on five journals (The Journal of Bone and Joint Surgery, The Bone and Joint Journal, The Spine Journal, European Spine Journal, and Spine), which were chosen based on their impact factors and authors' consensus. All abstracts were screened and articles addressing degenerative cervical spine surgery using PROIs were included. Articles were then analyzed for publication date, study design, journal, level of evidence, and PROI trends. Prevalence of PROIs and level of evidence of included articles were analyzed. Results From 19,736 articles published, 241 articles fulfilled our study criteria. Overall, 53 distinct PROIs appeared. The top seven most frequently used PROIs were: Japanese Orthopaedic Association score (104 studies), visual analog scale for pain (100), Neck Disability Index (72), Short Form-36 (38), Nurick score (25), Odom criteria (21), and Oswestry Disability Index (15). Only 11 PROIs were used in 5 or more articles. Thirty-three of the PROIs were appeared in only 1 article. Among the included articles, 16% were of level 1 evidence and 32% were of level 4 evidence. Conclusion Numerous PROIs are currently used in degenerative cervical spine surgery. A consensus on which instruments to use for a given diagnosis or procedure is lacking and may be necessary for better communication and comparison, as well as for the accumulation and analysis of vast clinical data across multiple studies.

Ninety-day readmissions after degenerative cervical spine surgery: A single-center administrative database study.

Unplanned hospital readmissions result in significant clinical and financial burdens to patients and the healthcare system. Readmission rates and causes have been investigated using large administrative databases which have certain limitations in data reporting and coding. The objective of this study was to provide a description of 90 day post-discharge readmissions following surgery for common degenerative cervical spine pathologies at a large-volume tertiary hospital. The study also compared the readmission rates of patients who underwent anterior- and posterior-approach procedures. The administrative records from a single-center, high-volume tertiary institution were queried using ICD-9 codes for common cervical pathology over a three year period to determine the rate and causes of readmissions within the 90 days following the index surgery. A total of 768 patients underwent degenerative cervical spine surgery during the three year study period. Within 90 days of discharge, 24 (3.13%) patients were readmitted; 16 (2.06%) readmissions were planned for lumbar surgery; 8 (1.04%) readmissions were unplanned. 640 patients underwent procedures involving an anterior approach and 128 patients underwent procedures involving a posterior approach. There were 14 (2.17%) planned readmissions in the anterior group and 2 (1.5%) in the posterior group. The unplanned readmission rate was 0.63% (4 patients) and 3.13% (4 patients) in the anterior and posterior groups, respectively. (p=0.0343). The 90 day post-discharge unplanned readmission rate that followed elective degenerative cervical spine surgery was 1.04%. The unplanned readmission rate associated with posterior-approach procedures (3.13%) was significantly higher than that of anterior-approach procedures (0.63%). IV.

Utilization of Patient Reported Outcome Instruments in Degenerative Cervical Spine Surgery

Patient centered health measures have become the gold standard to assess efficacy of surgical spine procedures and are an essential component of cost-effectiveness research. Currently, however, there is an expansive range of patient-reported outcome instruments without an established consensus as to which should be used for a particular diagnosis or procedure.

The Impact of Diabetes Mellitus on Patients Undergoing Degenerative Cervical Spine Surgery

Retrospective administrative database analysis. To determine the impact of glycemic control on perioperative complications and outcomes in patients undergoing degenerative cervical spine surgery. Diabetes mellitus (DM) is a highly prevalent systemic disease that has been shown to increase morbidity and mortality after spine surgery. Few studies have demonstrated negative effects on patients with DM who undergo cervical spine procedures; however, whether glycemic control influences surgical outcome is still unknown. The Nationwide Inpatient Sample was queried from 2002 to 2011. Patients who underwent cervical spine surgery for degenerative conditions were identified using the International Classification of Diseases Ninth Revision, Clinical Modification, codes. Three surgical cohorts were chosen: controlled diabetic, uncontrolled diabetic, and patients without diabetes. Patient demographics, surgical procedures, perioperative complications and postoperative outcomes were assessed. The prevalence of controlled and uncontrolled diabetic patients undergoing degenerative cervical spine surgery had been increasing significantly from 2002 to 2011. Compared with patients without diabetes, uncontrolled diabetic patients had significantly increased odds of respiratory, cardiac, and genitourinary complications. Uncontrolled diabetic patients also had significantly increased risk of pulmonary embolism and postoperative infection. Uncontrolled diabetic patients had increased risk of inpatient mortality (odds ratio = 6.39, 95% confidence interval = 4.09-10.00, P < 0.0001) and increased mean length of stay (almost 5 d) compared with nondiabetic patients. Similarly, controlled diabetic patients increased the odds of perioperative complications; however not nearly to the same degree. Controlled diabetic patients extended the mean length of stay by almost a day (P < 0.0001) and significantly increased costs compared with nondiabetic patients. Poor glycemic control increases the odds of inpatient mortality and perioperative complications in patients undergoing degenerative cervical spine surgery. Controlling DM before degenerative cervical spine surgery may lead to better outcomes and decreased costs. Therapeutic Level 3.

The value of neuromonitoring in cervical spine surgery.

Dear Editor, We read with interest the paper by Epstein entitled: The need to add motor evoked potential monitoring to somatosensory and electromyographic monitoring in cervical spine surgery.[1] The paper reviews the spine surgery literature regarding the use of intraoperative neural monitoring (IONM). Theoretically, IONM should alert the operative team that impending neurological injury is possible and a corrective maneuver performed to prevent such. IONM may be problematic in that it might alarm and result in an abandonment or alteration of the surgical procedure when no true neurological deficit is subsequently demonstrated (false positive). More worrisome, however, is the situation when no alert is observed and neurological injury ensued (false negative). Debate may be held with regard to the most appropriate surgical procedures for the use of IONM. Ideally, this should involve procedures in which potentially harmful maneuvers can be reversed. A classic example is deformity correction, which can be reversed if IONM suggests such. In cases in which “surgical reversal” is not possible, IONM has been shown to demonstrate true and false positives, however, studies have not demonstrated improved outcomes.[7] Many infer that IONM is associated with improved clinical results. However, it should be noted that the referenced studies compared outcomes with historical cohorts. Epstein et al.[2] reported 100 cases of IONM monitored cervical surgeries with no new neurological deficit. The historical cohort of this study included 218 patients operated in years 1985-1989, 8 of which became quadriplegic. This control population is clearly an outlier, as quadriplegia following elective cervical spine surgery for degenerative conditions is, indeed, a rarity and the rate is far less than the nearly 4% reported in the referenced study. Other studies cited by Epstein[1] show a high rate of false positives or false negatives with IONM, and low rate of true positives.[3,5,6] During degenerative cervical spine surgery, neurological injury may occur any of several phases. It may occur during induction of anesthesia with resultant hypotension, during positioning (flexion or extension) of the cervical spine in either prone or supine position, from intraoperative hypotension, and/or from direct surgical trauma. With the exception of hypotension and positioning, none of these potential causes of neurological injury are reversible. IONM, therefore can only signal that a neurological injury may have occurred, but does not afford the surgeon an enhanced opportunity to remedy or mitigate the neurological injury. When spinal cord injury occurs from direct surgical trauma, IONM serves only to document the timing of the trauma and cannot assist with altering the clinical outcome. There may then be little utility for IONM in degenerative cervical spine surgery. This conclusion has been borne out in the literature. Resnick et al.[7] reviewed the literature regarding IONM for degenerative cervical spine surgery. Their published guidelines concluded that relying on IONM changes as an indication for altering surgical procedure or administration of steroids has not been shown to reduce the incidence of neurological deterioration. The addition of IONM to degenerative cervical surgery has financial implications, however, cost-benefit analysis has not demonstrated benefit.[4] IONM is also often used for medico-legal reasons. Epstein reviewed the cervical spine surgery verdicts and determined the causes for verdicts were negligent surgery, lack of informed consent, failure to diagnose/treat, and failure to brace. She speculated that failure to adequately perform IONM may become the fifth reason for verdicts in cervical spine surgery. As the guidelines for cervical spinal surgery do not include the use of IONM,[7] and no clear algorithm for intraoperative action when IONM changes are observed, the routine use of IONM cannot serve as protection against a plaintiffs’ verdict. In the authors’ opinion, IONM in spine surgery has a definite role. This role includes intradural tumor surgery, deformity surgery, and cases in which patient positioning in and of itself poses neurological risk. IONM, however, has not been proven effective as a neuroprotective maneuver in the majority of cervical degenerative surgical procedures.

Surgical treatment of degenerative cervical spine diseases: Analyses of 90 patients clinical study

The effect of degenerative cervical spine surgery depends on good understanding of the pathogenesis and clinical course of disease with a detailed neurological and neuroradiological examination. Surgical approach should be considered separately for each pathological substrate in order to avoid additional morbidity. The aim of our study is to present the results of treatment through analysis of large clinical series focusing on anterior surgical approach with iliac crest graft fusion without cervical plating. The retrospective analysis of 90 patients operated on Neurosurgery of CHC Zemun, from 2008 to 2011, was done. In 81 patients cervical disc herniation was found in one or two levels, and 9 patients had spinal canal stenosis with polydiscopathy. Preoperatively 50 patients had cervical myelopathy, and 40 patients had radiculopathy as dominating clinical sign. Anterior cervical approach was performed in 79 patients, and 11 patients were operated by posterior approach. The treatment outcome was as follows: good outcome 16 (16.8%) patients, improved condition 65 (72.2%), without improvement 6 (6.7%), bad outcome 3 (4.3%). The anterior cervical approach with iliac crest autologous graft fusion, and without additional cervical plating, is reliable treatment option with results comparable to reported clinical series with sintetic graft placement and anterior cervical plate stabilisation.

Strengths and Limitations of International Classification of Disease Ninth Revision Clinical Modification Codes in Defining Cervical Spine Surgery

Retrospective study. To evaluate the sensitivity and specificity of International Classification of Disease Ninth Revision Clinical Modification (ICD9-CM) hospital discharge codes to define degenerative cervical spine surgery in comparison to patient operative notes in the medical record. Population-based studies of spine surgery have often relied on administrative databases as a primary information source, but little is known about the validity of using ICD9-CM codes to identify these operations. We performed a retrospective study comparing ICD9-CM billing codes to patient operative notes, the gold standard, for patients undergoing spine surgery in 2006 at a single academic center. We identified 1090 procedures of which 265 were categorized as cervical spine surgery for degenerative indications based on the operative notes. Compared to operative notes, our ICD9-CM algorithm had high sensitivity and specificity for selecting surgery at the cervical spine level and cervical spine surgery for degenerative indications. Categorization of cases by procedure had high sensitivity and specificity for fusion and surgical approach (>95%). Categorization of cases by primary diagnosis was generally less accurate. Cervical spondylosis with myelopathy was the most sensitive primary diagnosis. Categorization of cases by procedure had high sensitivity and specificity for fusion and surgical approach (≥96%). However, diagnoses such as herniated disc and procedures such as laminectomy had low sensitivity but high specificity. The use of our ICD9-CM algorithm to define spine surgery at the cervical spine level, and degenerative cervical spine surgery is highly accurate. Although specific diagnoses codes are mostly insensitive, an ICD9-CM algorithm can be used to study these procedures with reasonable precision.