Higher Modified Charlson Index Scores Are Associated With Increased Incidence of Complications, Transfusion Events, and Length of Stay Following Revision Hip Arthroplasty.

BACKGROUND: Revision total hip arthroplasty (RHA) has been associated with greater morbidity and length of stay (LOS) compared to primary total hip arthroplasty. Despite this, few validated metrics exist for risk stratification in RHA cohorts. The Charlson Comorbidity Index (CCI) has been associated with complications in total hip arthroplasty, but its utility in revision surgery remains unexplored. The purpose of this study was to examine the relationship between preoperative CCI and a variety of outcome metrics following RHA. METHODS: The National Surgical Quality Improvement Program database was used to identify all patients undergoing aseptic RHA between 2006 and 2013. A variety of demographics and perioperative variables were collected. Modified CCI scores were computed for each patient based on a validated formula incorporating comorbidities found in the National Surgical Quality Improvement Program database. Outcome variables of interest included mortality, major postoperative complications, minor adverse events, incidence of transfusion, and prolonged LOS. Perioperative factors were tested for association with these outcomes using bivariate analysis and significant variables were then incorporated into a logistic regression model to explore the relationship between preoperative CCI scores and postoperative events. RESULTS: In a multivariable regression model controlling for the significant perioperative variables, operative time, and American Society of Anesthesiologists classification, higher CCI scores were significantly associated with mortality (odds ratio [OR] 1.89, 95% confidence interval [CI] 1.64-2.18, P < .001), major complications (OR 1.12, 95% CI 1.05-1.20, P = .001), minor complications (OR 1.53, 95% CI 1.39-1.69, P < .001), transfusions (OR 1.14, 95% CI 1.09-1.20, P < .001), and prolonged LOS (OR 1.32, 95% CI 1.26-1.39, P < .001). CONCLUSION: Higher preoperative CCI scores were independent risk factors for numerous complications. This highlights the potential utility of the CCI in risk stratification for RHA populations.

Autologous Tumor Cell Lysate-Loaded Dendritic Cell Vaccine Inhibited Tumor Progression in an Orthotopic Murine Model for Hepatocellular Carcinoma.

The immune status of the tumor microenvironment influences tumor progression, and hepatocellular carcinoma (HCC) with an immunosuppressive signature often is associated with a poor prognosis. This study examined the impact of a bone marrow-derived dendritic cell (DC) vaccine loaded with autologous tumor cell lysate on tumor progression and the tumor microenvironment using an orthotopic murine HCC model. An orthotopic murine HCC was established by implantation of Hepa1-6 cells in the liver. The impact of DC vaccine loaded with Hepa1-6 cell lysate on tumor progression, survival, and tumor-infiltrating lymphocytes and cytokines was examined. Treating mice with DC vaccine loaded with Hepa1-6 cell lysate inhibited the progression of murine HCC generated through orthotopic implantation of Hepa1-6 cells and resulted in a 90 % survival rate by day 60 compared with a survival rate lower than 5 % for untreated mice. This anti-tumor response was associated with inhibition of STAT3 phosphorylation within the tumor. The DC vaccine reduced accumulation of Foxp3+CD4+ regulatory T cells within the tumor microenvironment and prevented TGF-ß production from the tumor tissue. Tumor cell lysate-loaded DC vaccine prevented HCC progression in a clinically relevant orthotopic murine HCC model. The effect of DC vaccine on the accumulation of Foxp3+CD4+ regulatory T cells within the tumor microenvironment and on the production of TGF-ß suggests that tumor regression by DC vaccination may be associated with an altered immunosuppressive tumor microenvironment.

Symptomatic Postoperative Epidural Hematoma in the Lumbar Spine.

A symptomatic postoperative epidural hematoma (SPEH) in the lumbar spine is a complication with variable presentation and the potential to rapidly cause an irrecoverable neurological injury. Significant heterogeneity exists among current case series reporting SPEH in the literature. This review attempts to clarify the known incidence, risk factors, and management pearls. Currently, literature does not support the efficacy of subfascial drains in reducing the incidence of SPEHs and possibly suggests that medication for thromboembolism prophylaxis may increase risk. Acute back pain and progressing lower extremity motor weakness are the most common presenting symptoms of SPEH. Magnetic resonance imaging is the mainstay of diagnostic imaging necessary to confirm the diagnosis, but if not acutely available, an immediate return to the operative theater for exploration without advanced imaging is justified. Treatment of a SPEH consists of emergent hematoma evacuation as a delay in repeat surgery has a deleterious effect on neurological recovery. Outcomes are poorly defined, though a significant portion of patients will have lasting neurological impairments even when appropriately recognized and managed.

The Incidence of Adjacent Segment Pathology After Cervical Disc Arthroplasty Compared with Anterior Cervical Discectomy and Fusion: A Systematic Review and Meta-Analysis of Randomized Clinical Trials.

OBJECTIVE: The aim of this study was to assess rates of adjacent segment degeneration (ASDeg), adjacent segment disease (ASDis), and reoperation rates as a result of adjacent segment pathology in patients who have undergone anterior cervical discectomy and fusion (ACDF) versus cervical disc arthroplasty (CDA). METHODS: A comprehensive search of randomized controlled trials was performed in PubMed from 2012 to 2019. Relevant studies included were assessed for quality using the Cochrane Beck Review Group guidelines. Rates of ASDeg, ASDis, and reoperation because of adjacent segment pathology were extracted and included in the final analysis. A random-effects and fixed-effects model was run among studies that showed high and low heterogeneity, respectively. RESULTS: A total of 19 studies were included in the final analysis, comprising 4655 patients. Overall, ACDFs reported significantly higher rates of ASDeg (19.7% vs. 14.4%; P < 0.001), ASDis (6.1% vs. 3.8%; P < 0.001), and reoperation rates (6.1% vs. 3.1%; P < 0.001) compared with CDAs, which was further corroborated in fixed-effects analysis. When stratified by length of follow-up, a significant difference was seen in ASDeg, ASDis, and reoperation rates of studies with follow-up of 12-48 months versus >48 months, with the exception of ASDeg rates in the CDA cohort. CONCLUSIONS: Our study shows CDA results in significantly lower ASDeg, ASDis, and reoperation rates. Although CDA may be a viable alternative to ACDF, further long-term studies are warranted to ensure consistency and establish longevity of our findings.

Non-invasive in vivo imaging for liver tumour progression using an orthotopic hepatocellular carcinoma model in immunocompetent mice.

BACKGROUND: Maintenance of complex transgenic colonies and labour-intensive techniques pose significant challenges in work involving mouse models for hepatocellular carcinoma (HCC). Other animal models of unusual species are generally impractical for research purposes. AIMS: To develop a highly reproducible orthotopic mouse model for HCC based on the murine α-foetoprotein (AFP), producing cell line Hepa1-6 and to monitor liver tumour progression via in vivo imaging, and measurement of plasma AFP. METHODS: Intrahepatic tumour was induced following subcapsular implantation of 10(+6) Hepa1-6 cells into C57L/J mice. AFP production was examined in vitro and in vivo using immunoblotting. Three confirmatory non-invasive imaging modalities were applied to follow tumour progression over time including ultrasound biomicroscopy (UBM), micromagnetic resonance imaging (microMRI), and bioluminescence. RESULTS: α-foetoprotein expression was confirmed both in vitro and in vivo, with increasing levels in the plasma as tumours progressed. UBM, microMRI and bioluminescence detected intrahepatic tumours to a 2 mm resolution by day 14. Sequential imaging studies demonstrated an intrahepatic pattern of disease progression with an observed median survival of 29 days. Immunosuppression of tumour-bearing mice led to a greater tumour size and decreased survival. CONCLUSIONS: Intrahepatic implantation of Hepa1-6 as a mouse model for HCC is a highly reproducible in vivo system with tumour biology analogous to human disease and is regulated by the presence of an intact host immune system. Tumour progression may be monitored in vivo by UBM, microMRI and bioluminescence. Plasma AFP increases over time, allowing redundancy in non-invasive means of following tumour progression.

Predictors of Readmission and Prolonged Length of Stay After Cervical Disc Arthroplasty.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The aim of the study was to assess which factors increase risk of readmission within 30 days of surgery or prolonged length of stay (LOS) (≥2 days) after cervical disc arthroplasty (CDA). SUMMARY OF BACKGROUND DATA: Several studies have shown noninferiority at mid- and long-term outcomes after cervical disc arthroplasty (CDA) compared to anterior cervical discectomy and fusion ACDF, but few have evaluated short-term outcomes regarding risk of readmission or prolonged LOS after surgery. METHODS: Demographics, comorbidities, operative details, postoperative complications, and perioperative outcomes were collected for patients undergoing single level CDA in the National Surgical Quality Improvement Program (NSQIP) database. Patients with prolonged LOS, defined as >2 days, and readmission within 30 days following CDA were identified. Univariable and multivariable logistic regression models were used to identify risk factors for prolonged LOS and readmission. RESULTS: A total of 3221 patients underwent single level CDA. Average age was 45.6 years (range 19-82) and 53% of patients were male. A total of 472 (14.7%) experienced a prolonged LOS and 36 (1.1%) patients were readmitted within 30 days following surgery. Predictors of readmission were postoperative superficial wound infection (odds ratio [OR] = 73.83, P < 0.001), American Society of Anesthesiologists (ASA) classification (OR = 1.98, P = 0.048), and body mass index (BMI) (OR = 1.06, P = 0.02). Female sex (OR = 1.76, P < 0.001), diabetes (OR = 1.50, P = 0.024), postoperative wound dehiscence (OR = 13.11, P = 0.042), ASA class (OR = 1.43, P < 0.01), and operative time (OR = 1.01, P < 0.001) were significantly associated with prolonged LOS. CONCLUSION: From a nationwide database analysis of 3221 patients, wound complications are predictors of both prolonged LOS and readmission. Patient comorbidities, including diabetes, higher ASA classification, female sex, and higher BMI also increased risk of prolonged LOS or readmission.Level of Evidence: 3.

Phylogeography of two moray eels indicates high dispersal throughout the indo-pacific.

Reef fishes disperse primarily as oceanic "pelagic" larvae, and debate continues over the extent of this dispersal, with recent evidence for geographically restricted (closed) populations in some species. In contrast, moray eels have the longest pelagic larval stages among reef fishes, possibly providing opportunities to disperse over great distances. We test this prediction by measuring mitochondrial DNA (mtDNA) and nuclear DNA variation in 2 species of moray eels, Gymnothorax undulatus (N = 165) and G. flavimarginatus (N = 124), sampled at 14-15 locations across the Indo-Pacific. The mtDNA data comprise 632 bp of cytochrome b and 596 bp of cytochrome oxidase I. Nuclear markers include 2 recombination-activating loci (421 bp of RAG-1 and 754 bp of RAG-2). Analyses of molecular variance and Mantel tests indicate little or no genetic differentiation, and no isolation by distance, across 22 000 km of the Indo-Pacific. We estimate that mitochondrial genetic variation coalesces within the past about 2.3 million years (My) for G. flavimarginatus and within the past about 5.9 My for G. undulatus. Permutation tests of geographic distance on the mitochondrial haplotype networks indicate recent range expansions for some younger haplotypes (estimated within approximately 600 000 years) and episodic fragmentation of populations at times of low sea level. Our results support the predictions that the extended larval durations of moray eels enable ocean-wide genetic continuity of populations. This is the first phylogeographic survey of the moray eels, and morays are the first reef fishes known to be genetically homogeneous across the entire Indo-Pacific.

Potential Selection Bias in Observational Studies Comparing Cervical Disc Arthroplasty to Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: Retrospective study using a national administrative database. OBJECTIVE: To define the cohort differences in patient characteristics between patients undergoing cervical disc arthroplasty (CDA) and anterior cervical discectomy and fusion (ACDF) in a large national sample, and to describe the impact of those baseline patient characteristics on analyses of costs and complications. SUMMARY OF BACKGROUND DATA: CDA was initially studied in high quality, randomized trials with strict inclusion criteria. Recently a number of non-randomized, observational studies have been published an attempt to expand CDA indications. These trials are predisposed to falsely attributing differences in outcomes to an intervention due to selection bias. METHODS: Adults undergoing ACDF or CDA between 2004 and 2014 were identified using International Classification of Diseases, 9, Clinical Modification (ICD-9-CM) diagnosis and procedure codes. Perioperative demographics, comorbidities, complications, and costs were queried. Patient characteristics were compared via chi-square and t tests. Cost, mortality, and complications were compared between ACDF and CDA cohorts using models that adjusted for demographics and comorbidities, as well as "naïve" models that did not. RESULTS: A total of 290,419 procedures, 98.2% ACDF and 1.8% CDA, were included in the sample. Compared with ACDF patients, CDA patients were younger, healthier as evidenced by number of comorbidities, and had an improved socioeconomic status as measured by income and insurance. The naïve logistic regression model showed that hospital costs for CDA were $549 lower than ACDF. In the fully specified model, CDA was $574 more expensive. The naïve model for medical complications suggests a protective advantage for CDA over ACDF, odds ratio of 0.627, P < 0.01. No statistically significant difference was found in the fully specified model in terms of complications. CONCLUSION: Patients undergoing CDA were younger and healthier with higher socioeconomic statuses compared with ACDF patients. Accounting for these baseline differences significantly attenuated the apparent benefit for CDR on costs and medical complications. LEVEL OF EVIDENCE: 3.

Hepatitis C Virus Infection as a Predictor of Complications and Increased Costs Following Primary Lumbar Fusion Surgery.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The aim of this study was to identify whether hepatitis C virus (HCV) diagnosis influences in-hospital lengths of stay (LOS), postoperative complications, readmission rates, or costs following primary posterior lumbar fusions in an elective setting. SUMMARY OF BACKGROUND DATA: Although joint arthroplasty literature has shown increased complication rates and costs for patients seropositive with HCV without liver disease compared to those without HCV, this comorbidity has not been explored in the spine literature. To our knowledge, this is the first publication in the lumbar spine literature to solely focus on HCV as the disease burden. METHODS: A national database was queried for patients who underwent primary lumbar spine fusion for degenerative lumbar pathology with Medicare insurance from 2005 to 2014. The 90-day postoperative complication rates, readmission rates, and treatment costs were queried. To limit confounding, HCV patients were matched with a control cohort of non-HCV patients using patient demographics, treatment modality, and comorbid conditions, and then analyzed by multivariate logistic regression. Patients with active liver disease were excluded to better isolate HCV as the comorbidity. RESULTS: A cohort of 28,841 patients were included in the final analysis. Postoperatively, compared to those without HCV infection, those with HCV had significantly higher odds of blood transfusions (odds ratio [OR]: 3.06), pneumonia (OR: 2.49), respiratory failure (OR: 2.49), urinary tract infections (OR: 1.89), wound-/implant-related infections (OR: 1.74), cerebrovascular events (OR: 1.70), or any postoperative complication within 90 days (OR: 2.93; all P < 0.0001). Furthermore, HCV positive patients had higher day of surgery costs ($28,713.26 vs. $25,448.26, P < 0.0001) and 90-day costs ($33,447.39 vs. $29,016.77, P < 0.0001). There was not a significant difference for patients with HCV infection compared to those without in regard to hospital LOS (10 days vs. 8 days, P = 0.332) and rates of a 90-day readmission (0.37% vs. 0.22%; OR: 1.70, 95% confidence interval: 1.00-2.90, P: 0.050). CONCLUSION: In patients undergoing primary lumbar fusion, a seropositivity for HCV without liver disease is associated with higher costs and complication rates, including higher rates of blood transfusion requirements and pneumonia-related complications. This data shed new light on elective spine surgery in HCV patients and may influence the risks and benefits considerations for surgeons considering lumbar fusion in this population. LEVEL OF EVIDENCE: 3.

Current incidence of adjacent segment pathology following lumbar fusion versus motion-preserving procedures: a systematic review and meta-analysis of recent projections.

BACKGROUND CONTEXT: Lumbar fusion has shown to be an effective surgical management option when indicated, improving patient outcomes and functional status. However, concerns of adjacent segment pathology (ASP) due to reduced mobility at the operated segment have fostered the emergence of motion-preserving procedures (MPP). PURPOSE: To assess rates of radiographic adjacent segment degeneration (ASDeg) and symptomatic adjacent segment disease (ASDis) as well as reoperation rates due to ASP in patients who have undergone lumbar fusion compared to motion-preservation for degenerative disorders. STUDY DESIGN: Systematic Review and Meta-Analysis. METHODS: Following PRISMA guidelines, a systematic review and meta-analysis was conducted to find current (1/2012-12/2019) retrospective cohort studies and randomized controlled trials evaluating rates of ASDeg, ASDis, and reoperations due to lumbar ASP. RESULTS: A total of 1,751 patients (791 underwent fusion surgery and 960 motion-preserving procedures) in 19 publications were included in the final analysis. Overall incidence rates of ASDeg, ASDis, and reoperation rates were 27.8%, 7.6%, and 4.6%, respectively. Results showed no significant difference between the lumbar fusion versus MPP cohorts in incidence of ASDeg (36.4% vs. 19.2%, p: 0.06), ASDis (10.7% vs. 4.42%, p: 0.25), or reoperation due to ASP (7.40% vs. 1.80%, p: 0.19). Fixed-effects analysis revealed patients who underwent MPP had significantly lower odds of ASDeg (OR: 2.57, CI: 1.95, 3.35, p<.05) and reoperations (OR: 3.18, CI: 1.63, 6.21, p<.05) compared to lumbar fusion patients. CONCLUSIONS: This meta-analysis revealed no statistically significant difference in incidence of ASDeg, ASDis, or reoperations due to ASP for patients after lumbar fusion versus MPP. Weighted analysis, however, showed that MPP patients had significantly lower odds of ASDeg and reoperations due to ASP. While previous studies have established the biomechanical efficacy of MPP on cadaveric models, further high-quality studies are required to evaluate the long-term consequences of these procedures on patient-reported outcomes, postoperative complications, and associated inpatient/outpatient costs.

Trends in Leadership at Spine Surgery Fellowships.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To illustrate demographic trends among spine fellowship leaders (FLs). SUMMARY OF BACKGROUND DATA: No previous study in the orthopedic literature has analyzed the demographic characteristics or past surgical training of FL in an orthopedic sub-specialty. We attempt to illustrate demographic trends among spine fellowship leadership including fellowship directors (FDs) and co-fellowship directors (co-FDs). We also highlight the institutions that have trained these leaders at various levels. METHODS: Our search for FDs was constructed from the 2018 to 2019 North American Spine Surgery (NASS) Fellowship Directory. Datapoints gathered included: age, sex, residency/fellowship training location, time since training completion until FD appointment, length in FD role, and personal research H-index. RESULTS: We identified 103 FLs consisting of 67 FDs, 19 co-FDs, and another 16 individuals with a synonymous leadership title. 96.1% (99) of the leadership consisted of males while 3.9% (4) were female. The mean age was 52.9 years old and the mean h-index of the FLs was 23.8. FLs were trained in orthopedic surgery (n = 89), neurosurgery (n = 13), or combined orthopedic surgery and neurosurgery training (n = 1). The top fellowships programs producing future FLs were: Case Western Reserve University, Cleveland (n = 10), Washington University, St. Louis (n = 9), and Rothman Orthopaedic Institute, Thomas Jefferson University, Philadelphia (n = 7). CONCLUSION: Spine surgery fellowship directors are more likely to have graduated from certain residency and fellowship programs. This finding could be a result of the training provided by these centers or the institution's predilection to select applicants that are more likely to later seek academic leadership roles post-training. LEVEL OF EVIDENCE: 4.

Mobile messaging and smartphone apps for patient communication and engagement in spine surgery.

Mobile health (mHealth) applications are rapidly becoming increasingly available to patients. These interventions utilize simple mobile messaging (SMS) and software applications on mobile devices for a variety of purposes. In the surgical population mHealth applications have shown promise in increasing medication and protocol adherence, monitoring patients after surgery, and helping modify behaviors associated with poor surgical outcomes. There is a paucity of spine specific applications at this time. Further development and study of efficacy of spine specific mHealth applications is needed.

Lumbar Interbody Fusions for Degenerative Spondylolisthesis: Review of Techniques, Indications, and Outcomes.

STUDY DESIGN: Broad narrative review. OBJECTIVES: To review and summarize the current literature on the outcomes, techniques, and indications of lumbar interbody fusion in degenerative spondylolisthesis. METHODS: A thorough review of peer-reviewed literature was performed on the outcomes, techniques, and indications of lumbar interbody fusions in degenerative spondylolisthesis. RESULTS: A number of studies have found similar results between interbody fusions and posterolateral fusion in the setting of degenerative spondylolisthesis. There is some evidence that suggests that interbody fusion may be a useful adjunct in the setting of unstable degenerative spondylolisthesis. The number of options for interbody fusions has quickly expanded. Initially, interbody fusions were accomplished via an anterior approach. Posterior and transforaminal interbody fusions are 2 options that accomplish an interbody fusion without the morbidity of an anterior approach. Over the past decade, minimally invasive options including extreme lateral, oblique, and minimally invasive transforaminal interbody fusions have gained popularity. CONCLUSIONS: Lumbar interbody fusion can be a useful tool in the setting of unstable degenerative spondylolisthesis. A number of technique options, both open and minimally invasive, are available to accomplish an interbody fusion. The literature to this date does not support a clear benefit of one technique over others in the setting of degenerative spondylolisthesis.

Coagulation Laboratory Testing Is Predictive of Wound Complications Following Microdiscectomy.

STUDY DESIGN: Retrospective review. OBJECTIVE: To determine whether abnormal preoperative testing is associated with postoperative complications in patients undergoing a microdiscectomy. METHODS: Patients undergoing a microdiscectomy between 2006 and 2013 were identified in the National Surgical Quality Improvement Program database based on appropriate current procedural terminology coding. Thirty-day postoperative complications were analyzed in addition to patient demographics, comorbidities, and abnormal preoperative laboratory values. A series of over 650 univariate analyses to determine which independent variables to include for each complication were completed. Based on those analyses, 12 logistic regression models were built, one for each specific complication. Each model adjusted for age, gender, comorbidities, American Society of Anesthesiologists classification, as well as operative time. RESULTS: A total of 5947 patients undergoing a microdiscectomy were included in the study. Abnormal preoperative international normalized ratio (odds ratio [OR] = 5.85, P < .05) was associated with any wound infection, superficial or deep, and abnormal partial thromboplastin time was significantly associated with wound dehiscence (OR = 6.80, P < .05). Postoperative urinary tract infections were associated with abnormal preoperative hematocrit (OR = 8.00, P < .05). None of the identified preoperative labs were independently associated with pulmonary embolism, organ space surgical site infections, or intubation. CONCLUSIONS: Abnormal preoperative coagulation labs were significantly associated with postoperative wound complications. However, the majority of tests were not associated with adverse events following microdiscectomy. Further study is necessary to conclude whether these tests provide information that can modify perioperative management and whether widespread testing is cost-effective.

Fibromyalgia as a Predictor of Increased Postoperative Complications, Readmission Rates, and Hospital Costs in Patients Undergoing Posterior Lumbar Spine Fusion.

STUDY DESIGN: Retrospective review. OBJECTIVE: The aim of this study was to identify whether a concomitant diagnosis of fibromyalgia (FM) influences postoperative complications, readmission rates or cost following primary 1 to 2 level lumbar fusions in an elective setting. SUMMARY OF BACKGROUND DATA: Patients with FM often are limited by chronic lower back pain, many of whom will seek operative treatment. No previous study has evaluated whether patients with a concomitant diagnosis of FM have more complications following spine surgery. METHODS: Medicare data (2005-2014) from a national database was queried for patients who underwent primary 1 to 2 level posterolateral lumbar spine fusion for degenerative lumbar pathology. Thirty- and 90-day postoperative complication rates, readmission rates, and treatment costs were queried. To reduce confounding, FM patients were matched with a control cohort of non-FM patients using patient demographics, treatment modality, and comorbid conditions, and then analyzed by multivariable logistic regression. RESULTS: Within the first 30-day postoperative, acute post hemorrhagic anemia (odds ratio [OR]: 2.58; P < 0.001) and readmission rates were significantly higher in FM patients compared to controls. There was no significant difference in wound related complications within first 30-days (0.19% vs. 0.23%; P = 0.520) or with length of stay (3.60 vs. 3.53 days; P = 0.08). Within 90-day postoperative, FM patients had higher rates of pneumonia (OR: 3.73; P < 0.001) and incurred 5.31% more in hospital charges reimbursed compared to the control cohort. CONCLUSION: Primary 1 to 2 level lumbar fusions performed on FM patients have higher rates of postoperative anemia, pneumonia, cost of care, and readmission compared to match controls. FM patients and surgeons should be aware of these increased risks in an effort to control hospital costs and potential complications. LEVEL OF EVIDENCE: 3.

Software-Based Postoperative Communication With Patients Undergoing Spine Surgery.

STUDY DESIGN: Observational study. OBJECTIVES: Perioperative patient anxiety is a major concern in orthopedic surgery. Mobile messaging applications have been used in a number of healthcare settings. The goal of this project is to develop a novel mobile messaging application aimed at decreasing perioperative patient anxiety in spine surgery patients. METHODS: Postoperative recovery journals were collected from patients undergoing spine surgery. Journals were used as a framework to develop a software-messaging library. A subsequent cohort of patients received daily text messages with educational material regarding their recovery for 14 days after discharge from their operative admission. Patients ranked the usefulness of the survey on day 14; further feedback was obtained via interviews. RESULTS: Nineteen postoperative recovery journals were collected and analyzed. Content regarding postoperative recovery was compiled. The pilot group consisted of 21 patients. Average rating of the application on a 1 to 5 scale with 5 being "very useful" was 4.57. Of the 12 patients available for postoperative interviews, 11 felt the content of the messages was relevant. Nine of 12 patients felt the application made it less likely for them to call clinic. CONCLUSIONS: The study presents a unique mobile phone messaging tool to offer patients support in the 2 weeks following spine surgery. The tool was felt to be useful by nearly all patients, had a high degree of patient engagement, and made the majority of patients less likely to call clinic.

Preoperative Risk Stratification in Spine Tumor Surgery: A Comparison of the Modified Charlson Index, Frailty Index, and ASA Score.

STUDY DESIGN: A retrospective review of prospectively collected data. OBJECTIVE: The purpose of this study is to compare and validate several preoperative scores for predicting outcomes following spine tumor resection. SUMMARY OF BACKGROUND DATA: Preoperative risk assessment for patients undergoing spinal tumor resection remains challenging. At present, few risk assessment tools have been validated in this high-risk population. METHODS: The 2008 to 2014 National Surgical Quality Improvement database was used to identify all patients undergoing surgical resection of spinal tumors, stratified as extradural, intradural extramedullary, and intramedullary based on CPT codes. American Society of Anesthesiologists (ASA) score, modified Charlson Comorbidity Index (CCI), and modified Frailty Index (mFI) were computed. A binary logistic regression model was used to explore the relationship between these variables and postoperative outcomes, including mortality, major and minor adverse events, and hospital length of stay (LOS). Other significant variables such as demographics, operative time, and tumor location were controlled for in each model. RESULTS: Two thousand one hundred seventy patients met the inclusion criteria. Higher CCI scores were independent predictors of mortality (OR = 1.24, 95% CI: 1.14-1.36, P < 0.001), major adverse events (OR = 1.07, 95% CI: 1.01-1.31, P = 0.018), minor adverse events (OR = 1.15, 95% CI: 1.10-1.20, P < 0.001), and prolonged LOS (OR = 1.14, 95% CI: 1.09-1.19, P < 0.001). Patients' mFI scores were significantly associated with mortality and LOS, but not major or minor adverse events. ASA scores were not associated with any outcome metric when controlling for other variables. CONCLUSION: The CCI demonstrated superior predictive capacity compared with mFI and ASA scores and may be valuable as a preoperative risk assessment tool for patients undergoing surgical resection of spinal tumors. The validation of assessment scores is important for preoperative risk stratification and improving outcomes in this high-risk group. LEVEL OF EVIDENCE: 3.

Complications and Risk Factors Using Structural Allograft Versus Synthetic Cage: Analysis 17 783 Anterior Cervical Discectomy and Fusions Using a National Registry.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To determine the rates of perioperative complications in patients undergoing anterior cervical discectomy and fusion (ACDF) with allograft versus synthetic cage. METHODS: A large national administrative health care database was queried for ACDF procedures performed between 2007 and 2014 using ICD-9 (International Statistical Classification of Diseases, 9th revision) and CPT (Current Procedural Terminology) codes. Cases that utilized structural allograft and synthetic cages were identified via CPT codes. Gender, age, frequency of obesity, cigarette use, diabetes, and number of levels fused were compared between the 2 cohorts using χ2 test. Complications within 90 days were identified via ICD-9 codes and compared between the 2 cohorts. Revision rates within 2 years were noted. RESULTS: A total of 10 648 ACDF cases using synthetic cages and 7135 ACDFs using structural allograft were identified. The demographics between the 2 cohorts were similar. Overall complication rate was 8.71% in the synthetic cage group compared with 7.76% in the structural allograft group (P < .01). Use of synthetic cage was associated with higher rate of respiratory complications, 0.57% compared with 0.31% in the structural allograft cohort (P = .03), while use of structural allograft was associated with a higher rate of dysphagia, 0.64% compared with 0.33% (P < .01). Revision rate at 2 years was 0.50% and 0.56% in the synthetic cage and allograft groups, respectively (P = .03). CONCLUSIONS: This data suggests that synthetic cages are associated with a marginally higher overall rate of complications with similar revision rates.

The utility of preoperative laboratories in predicting postoperative complications following posterolateral lumbar fusion.

BACKGROUND CONTEXT: Several studies have suggested that laboratory results have minimal impact on clinical decision making in surgery. Despite the widespread use of preoperative testing in spine surgery and the large volume of posterolateral lumbar fusions (PLFs) being performed each year, no study has assessed the ability of preoperative laboratories to predict adverse events following PLF. PURPOSE: The purpose of this study was to explore the relationship between commonly obtained preoperative laboratory results and postoperative complications following one- to two-level PLF. STUDY DESIGN: This is a retrospective study of prospectively collected data. PATIENT SAMPLE: The 2006-2013 American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was employed to identify all patients who underwent one- to two-level PLF. OUTCOME MEASURES: The outcome variables of interest were 30-day postoperative complications, which were assessed as major complications, minor adverse events, and total complications. MATERIALS AND METHODS: Demographics, comorbidities, and perioperative characteristics were collected for each patient. Preoperative laboratories included sodium, blood urea nitrogen, creatinine, albumin, bilirubin, serum glutamic oxaloacetic transaminase, alkaline phosphatase, white blood cell count, hematocrit, platelet count, prothrombin time, international normalized ratio, and partial thromboplastin time. Bivariate analysis and multivariate logistic regression modeling were used to explore the relationship between abnormal preoperative laboratories and the incidence of postoperative complications. RESULTS: After controlling for age, ASA score, length of surgery, and all significant comorbidities, abnormal sodium (odds ratio [OR]=2.47, 95% confidence interval [CI]: 1.45-4.19, p=.001) and abnormal INR (OR=2.33, 95% CI: 1.09-4.98, p=.029) were significantly associated with the development of any complication. Sodium (OR=1.61, 95% CI: 1.01-2.54, p=.04) and platelets (OR=1.58, 95% CI: 1.02-2.44, p=.04) were associated with minor complications. Meanwhile, creatinine (OR=1.74, 95% CI: 1.02-2.99, p=.04) and platelets (OR=1.71, 95% CI: 1.02-2.89, p=.04) were significant predictors of major adverse events. CONCLUSIONS: This study represents the first attempt to assess the utility of preoperative laboratories in predicting postoperative complications in PLF. Although the majority of laboratories were not significantly associated with adverse events, abnormal sodium values, INR, creatinine, and platelets were shown to be predictive of various complications.

Evidence of an Inherited Predisposition for Spinal Cord Tumors.

STUDY DESIGN: Retrospective study. OBJECTIVES: To determine familial clustering of primary spinal cord tumors using a statewide genealogy database. METHODS: The Utah Population Database (UPDB) was queried using ICD-Oncology (International Classification of Diseases for Oncology) codes for primary spinal cord tumors. The hypothesis of disproportionate familial clustering was tested using the Genealogical Index of Familiality (GIF). The relative risks (RRs) in relatives were calculated using the ratio of observed spinal cord tumors to expected spinal cord tumors in relatives using estimated rates from the UPDB. The related clusters of spinal cord cancer cases with a significant excess number of spinal cord cancer cases descending from a common founder pair were identified using internal UPDB rates. RESULTS: The analysis of the GIF for individual with tumors of the spinal cord showed excess close and distant relatedness (case GIF = 3.82; control mean GIF = 2.68; P = .068). Excess relatedness for spinal cord cancers was observed when only more distant relationships were considered (P = .019). The RRs for spinal cord tumors were elevated in second- and third-degree relatives but this did not reach statistical significance (RR = 2.9, P = .15, and RR = 2.0, P = .14). Multiple extended pedigrees with a significant excess of spinal cord cancer cases among the descendants were identified. CONCLUSIONS: The excess relatedness of tumor cases over controls in distant relationships, the higher RRs to distant relatives, and the discovery of high-risk pedigrees all suggest a familial predisposition to the development of spinal cord tumors.