Projections of Single-level and Multilevel Spinal Instrumentation Procedure Volume and Associated Costs for Medicare Patients to 2050.

BACKGROUND: Instrumented spinal fusions can be used in the treatment of vertebral fractures, spinal instability, and scoliosis or kyphosis. Construct-level selection has notable implications on postoperative recovery, alignment, and mobility. This study sought to project future trends in the implementation rates and associated costs of single-level versus multilevel instrumentation procedures in US Medicare patients aged older than 65 years in the United States. METHODS: Data were acquired from the Centers for Medicare & Medicaid Services from January 1, 2000, to December 31, 2019. Procedure costs and counts were abstracted using Current Procedural Terminology codes to identify spinal level involvement. The Prophet machine learning algorithm was used, using a Bayesian Inference framework, to generate point forecasts for 2020 to 2050 and 95% forecast intervals (FIs). Sensitivity analyses were done by comparing projections from linear, log-linear, Poisson and negative-binomial, and autoregressive integrated moving average models. Costs were adjusted for inflation using the 2019 US Bureau of Labor Statistics' Consumer Price Index. RESULTS: Between 2000 and 2019, the annual spinal instrumentation volume increased by 776% (from 7,342 to 64,350 cases) for single level, by 329% (from 20,319 to 87,253 cases) for two-four levels, by 1049% (from 1,218 to 14,000 cases) for five-seven levels, and by 739% (from 193 to 1,620 cases) for eight-twelve levels (P < 0.0001). The inflation-adjusted reimbursement for single-level instrumentation procedures decreased 45.6% from $1,148.15 to $788.62 between 2000 and 2019, which is markedly lower than for other prevalent orthopaedic procedures: total shoulder arthroplasty (-23.1%), total hip arthroplasty (-39.2%), and total knee arthroplasty (-42.4%). By 2050, the number of single-level spinal instrumentation procedures performed yearly is projected to be 124,061 (95% FI, 87,027 to 142,907), with associated costs of $93,900,672 (95% FI, $80,281,788 to $108,220,932). CONCLUSIONS: The number of single-level instrumentation procedures is projected to double by 2050, while the number of two-four level procedures will double by 2040. These projections offer a measurable basis for resource allocation and procedural distribution.

External Validation of an Online Wound Infection and Wound Reoperation Risk Calculator After Metastatic Spinal Tumor Surgery.

STUDY DESIGN: This was a single-institutional retrospective cohort study. OBJECTIVE: Wound infections are common following spine metastasis surgery and can result in unplanned reoperations. A recent study published an online wound complication risk calculator but has not yet undergone external validation. Our aim was to evaluate the accuracy of this risk calculator in predicting 30-day wound infections and 30-day wound reoperations using our operative spine metastasis population. METHODS: An internal operative database was used to identify patients between 2012 and 2022. The primary outcomes were 1) any surgical site infection and 2) wound-related revision surgery within 30 days following surgery. Patient details were manually collected from electronic medical records and entered into the calculator to determine predicted complication risk percentages. Predicted risks were compared to observed outcomes using receiver operator characteristic (ROC) curves with areas under the curve (AUC). RESULTS: A total of 153 patients were included. The observed 30-day postoperative wound infection incidence was 5% while the predicted wound infection incidence was 6%. In ROC analysis, good discrimination was found for the wound infection model (AUC = 0.737; P = 0.024). The observed wound reoperation rate was 5% and the predicted wound reoperation rate was 6%. ROC analysis demonstrated poor discrimination for wound reoperations (AUC = 0.559; P = 0.597). CONCLUSIONS: The online wound-related risk calculator was found to accurately predict wound infections but not wound reoperations within our metastatic spine surgery cohort. We suggest that the model may be clinically useful despite underlying population differences, but further work must be done to generate and validate accurate prediction tools.

The prognostic role of neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and systemic immune-inflammation index on short- and long-term outcome following surgery for spinal metastases.

OBJECTIVE: Inflammatory markers such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII) have shown promise in predicting mortality in various types of cancer. The purpose of this study was to assess NLR, PLR, and SII in predicting 30-day mortality and overall survival (OS) among surgically treated patients with spinal metastasis. METHODS: This was a retrospective study including 153 patients who underwent surgery for spinal metastasis between 2012 and 2022. Electronic medical records were manually reviewed, and NLR, PLR, and SII were calculated from preoperative neutrophil, platelet, and lymphocyte counts. Receiver operating characteristic curves with areas under the curve were generated to determine cutoff values. Logistic regression was used to determine the odds ratios (ORs) for 30-day mortality. The Kaplan-Meier method and Cox regression were used to determine the hazard ratio (HR) for OS limited to 5 years postoperatively. RESULTS: Preoperative cutoff values were as follows: NLR > 10.2, PLR > 260, and SII > 2900. Overall, 35.9% (55/153) of patients had elevated NLR, 45.7% (70/153) had elevated PLR, and 30.7% (47/153) had elevated SII. The overall 30-day mortality was 8.5% (13/153). After controlling for confounders such as performance status and primary tumor type, high NLR (OR 5.20, 95% CI 1.21-22.28; p = 0.026) and SII (OR 4.92, 95% CI 1.17-20.63; p = 0.029) were associated with increased odds of 30-day postoperative mortality. The median OS time in the study population was 26 months (95% CI 12-40 months). After controlling for confounders such as Eastern Cooperative Oncology Group status, primary tumor, and hypoalbuminemia, high NLR was associated with shorter OS (HR 2.23, 95% CI 1.48-3.97; p = 0.003). CONCLUSIONS: High preoperative NLR and SII were independently associated with 30-day postoperative mortality in this study. Elevated NLR was also found to be associated with shorter OS. The prognostic role of these metrics warrants further investigation.

Predictors of mortality in chronic subdural hematoma evacuation.

Chronic subdural hematoma (cSDH) is one of the most common types of intracranial hemorrhages, particularly in the elderly. Despite extensive research regarding cSDH diagnosis and treatment, there is conflicting data on predictors of postoperative mortality (POM). We conducted a large retrospective review of patients who underwent a cSDH evacuation at a single urban institution between 2015 and 2022. Data were collected from the electronic medical record on prior comorbidities, anticoagulation use, mental status on presentation, preoperative labs, and preoperative/postoperative imaging parameters. Univariate and multivariate analyses were conducted to analyze predictors of mortality. Mortality during admission for this cohort was 6.1%. Univariate analysis showed the mortality rate was higher in those presenting with a history of dialysis. In addition, those who presented with altered mental status, were intubated, and lower GCS scores had higher rates of POM. Usage of Coumadin was correlated with higher rates of POM. Examination of preoperative labs showed that patients who presented with anemia or thrombocytopenia had higher POM. Imaging data showed that cSDH volume and greatest dimension were correlated with higher rates of POM. Finally, patients that were not extubated postoperatively had higher rates of POM. Multivariate analysis showed that only altered mental status and being not being extubated postoperatively were correlated with a higher risk of mortality. In summation, we demonstrated that altered mental status and failure to extubate were independent predictors or mortality in cSDH evacuation. Interestingly, patient age was not a significant predictor of mortality.

Spinal Cord Signal Intensity Predicts Functional Outcomes in the Operative Management of Degenerative Cervical Myelopathy.

STUDY DESIGN: Prospective single institutional cohort study on degenerative cervical myelopathy (DCM) from 2009 to 2022. OBJECTIVE: This study aims to assess the relationship among preoperative spinal cord signal change, postoperative signal change evolution, and functional outcome in patients undergoing surgery for DCM. SUMMARY OF BACKGROUND DATA: There is conflicting evidence on whether spinal cord signal intensity influences functional outcomes in patients with DCM. PATIENTS AND METHODS: This prospective study investigated 104 patients with DCM that underwent both preoperative and routine postoperative cervical spine magnetic resonance imaging (MRI) as part of a research protocol. Signal intensity/grade, modified Japanese Orthopedic Association (mJOA) scores, signal resolution, and patient demographics were assessed. RESULTS: Sixty-eight of the subjects were found to have abnormal T2 spinal cord signal intensity changes on their preoperative MRI. The total mean preoperative mJOA score was 13.6, increasing postoperatively to 16 (P < 0.001). The presence or absence of preoperative spinal cord signal change was not associated with the change in mJOA score or neurological recovery rate after surgery. Of the 68 patients with preoperative T2 signal change, 36 were found to have an improvement in the T2-weighted signal grade after surgery and 32 had no change in postoperative signal grade. The mean improvement in mJOA score (3.7) and neurological recovery rate (70.3%) was significantly higher in the patients with preoperative signal change whose postoperative MRI signal change grade improved by at least one point compared with those that did not (2.0, 50.5%), (P < 0.001, P < 0.003). CONCLUSIONS: The presence of preoperative T2-weighted signal change was associated with lower preoperative mJOA scores, but no change in mJOA after surgery or postoperative neurological recovery rate. However, improvement in T2-weighted spinal cord signal grade on postoperative MRI was significantly associated with a degree of neurological improvement after surgery.

Is perioperative blood transfusion associated with postoperative thromboembolism or infection after metastatic spinal tumor surgery?

STUDY DESIGN: Retrospective cohort. SUMMARY OF BACKGROUND DATA: Patients with metastatic spine disease who undergo surgical intervention have a high risk of requiring red blood cell (RBC) transfusion. Perioperative transfusion has been independently associated with increased risk of venous thromboembolic (VTE) and infectious complications following orthopedic procedures and degenerative spinal intervention; however, literature within spine oncology is limited. OBJECTIVE: To determine the association between perioperative RBC transfusion and postoperative VTE or infection following spinal tumor surgery. METHODS: A total of 153 patients who underwent surgery for spinal metastases between April 2012 and April 2022 were included. Medical records were reviewed to identify RBC transfusion administered either intraoperatively or within 96 h following surgery. The primary endpoints were: 1) development of any VTE or 2) development of any infection within 30 days following surgery. Any VTE was defined as deep vein thrombosis or pulmonary embolism, and any infection was defined as pneumonia, meningitis, Clostridium difficile infection, urinary tract infection, surgical site infection, or sepsis. Logistic regression analyses were performed. RESULTS: Of the 153 patients included in the study, 43 % received a perioperative RBC transfusion. The overall incidence of postoperative VTE and infection was 15 % and 22 %, respectively. In univariate analysis, perioperative transfusion was not associated with postoperative VTE (odds ratio [OR] 2.41; 95 % confidence interval [CI] 0.97-6.00; p = 0.058) but was associated with infection (OR 3.02; 95 % CI 1.36-6.73; p = 0.007). After adjusting for confounders such as performance status, operative time, and surgical extent, transfusion was not associated with both VTE (OR 1.25; 95 % CI 0.36-4.32; p = 0.727) or infection (OR 1.86; 95 % CI 0.70-4.92; p = 0.210). While not statistically significant, sub-analyses demonstrated a trend towards increased VTE incidence in patients requiring transfusion earlier (within 24 h) as opposed to later postoperatively. CONCLUSIONS: We found that perioperative transfusion was not an independent predictor of 30-day postoperative VTE or infection in patients undergoing metastatic spinal surgery. Further exploration of time-dependent transfusion outcomes is warranted.

The prognostic nutritional index (PNI) is independently associated with 90-day and 12-month mortality after metastatic spinal tumor surgery.

INTRODUCTION: Estimated postoperative survival is an important consideration during the decision-making process for patients with spinal metastases. Nutritional status has been associated with poor outcomes and limited survival in the general cancer population. The objective of this study was to evaluate the predictive utility of the prognostic nutritional index (PNI) for postoperative mortality after spinal metastasis surgery. METHODS: A total of 139 patients who underwent oncologic surgery for spinal metastases between April 2012 and August 2022 and had a minimum 90-day follow-up were included. PNI was calculated using preoperative serum albumin and total lymphocyte count, with PNI < 40 defined as low. The mean PNI of our cohort was 43 (standard deviation: 7.7). The primary endpoint was 90-day mortality, and the secondary endpoint was 12-month mortality. Multivariate logistic regression analyses were performed. RESULTS: The 90-day mortality was 27% (37/139), and the 12-month mortality was 56% (51/91). After controlling for age, ECOG performance status, total psoas muscle cross-sectional area (TPA), and primary cancer site, the PNI was associated with 90-day mortality [odds ratio 0.86 (95% confidence interval 0.79-0.94); p = 0.001]. After controlling for ECOG performance status and primary cancer site, the PNI was associated with 12-month mortality [OR 0.89 (95% CI 0.82-0.97); p = 0.008]. Patients with a low PNI had a 50% mortality rate at 90 days and an 84% mortality rate at 12 months. CONCLUSION: The PNI was independently associated with 90-day and 12-month mortality after metastatic spinal tumor surgery, independent of performance status, TPA, and primary cancer site.

Predictive value of six nutrition biomarkers in oncological spine surgery: a performance assessment for prediction of mortality and wound infection.

OBJECTIVE: Assessment of nutritional status is fundamental in cancer patients. The objective of this study was to assess the predictive ability of 6 nutritional biomarkers for postoperative mortality and wound infection after metastatic spinal tumor surgery. METHODS: A total of 139 patients who underwent oncological surgery for metastatic spine disease between April 2012 and August 2022 and had a minimum follow-up of 90 days were included. Six unique nutritional biomarkers were assessed: Prognostic Nutritional Index (PNI), Nutritional Risk Index (NRI), Controlling Nutritional Status Score (CONUT), total psoas cross-sectional area (TPA), body mass index (BMI), and body weight. Study endpoints were 90-day mortality rate, 12-month mortality rate, and wound infection. The discriminative ability of each of these markers was assessed with the c-statistic. A multivariate analysis was done for each of the biomarkers after a univariate analysis was first performed. RESULTS: The 90-day mortality rate was 27% (37 of 139). The biomarkers and respective c-statistics were as follows: PNI (0.74), NRI (0.75), CONUT (0.71), TPA (0.64), BMI (0.59), and body weight (0.60). The 12-month mortality rate was 56% (51 of 91). The biomarkers and respective c-statistics were as follows: PNI (0.72), NRI (0.73), CONUT (0.70), TPA (0.63), BMI (0.59), and body weight (0.60). The wound infection rate was 8% (11 of 139). The biomarkers and respective c-statistics were as follows: PNI (0.57), NRI (0.53), CONUT (0.55), TPA (0.57), BMI (0.48), and body weight (0.52). The PNI, NRI, and CONUT all predicted 90-day and 12-month mortality after multivariate regression analysis. No association between nutrition and wound infection was found. CONCLUSIONS: In this study, nutritional status was associated with postoperative mortality following oncological spine surgery. Three biomarkers predicted outcome independent of variables such as performance status or primary cancer. Future validation of these metrics is needed.

Evaluation of lymphopenia as a predictor of postoperative mortality and major complications in patients undergoing surgery for metastatic spine tumors.

OBJECTIVE: Lymphopenia is often seen in advanced metastatic disease and has been associated with poor postoperative outcomes. Limited research has been done to validate this metric in patients with spinal metastases. The objective of this study was to evaluate the capability of preoperative lymphopenia to predict 30-day mortality, overall survival (OS), and major complications in patients undergoing surgery for metastatic spine tumors. METHODS: A total of 153 patients who underwent surgery for metastatic spine tumor between 2012 and 2022 and met the inclusion criteria were examined. Electronic medical record chart review was conducted to obtain patient demographics, comorbidities, preoperative laboratory values, survival time, and postoperative complications. Preoperative lymphopenia was defined as < 1.0 K/µL based on the institution's laboratory cutoff value and within 30 days prior to surgery. The primary outcome was 30-day mortality. Secondary outcomes were OS up to 2 years and 30-day postoperative major complications. Outcomes were assessed with logistic regression. Survival analyses were done using the Kaplan-Meier method with log-rank test and Cox regression. Receiver operating characteristic curves were plotted to classify the predictive ability of lymphocyte count as a continuous variable on outcome measures. RESULTS: Lymphopenia was identified in 47% of patients (72 of 153). The overall 30-day mortality rate was 9% (13 of 153). In logistic regression analysis, lymphopenia was not associated with 30-day mortality (OR 1.35, 95% CI 0.43-4.21; p = 0.609). The mean OS in this sample was 15.6 months (95% CI 13.9-17.3 months), with no significant difference between patients with lymphopenia and those with no lymphopenia (p = 0.157). Cox regression analysis did not show an association between lymphopenia and survival (HR 1.44, 95% CI 0.87-2.39; p = 0.161). The major complication rate was 26% (39 of 153). In univariable logistic regression analysis, lymphopenia was not associated with the development of a major complication (OR 1.44, 95% CI 0.70-3.00; p = 0.326). Finally, receiver operating characteristic curves generated poor discrimination between lymphocyte count and all outcomes, including 30-day mortality (area under the curve 0.600, p = 0.232). CONCLUSIONS: This study does not support prior research that had shown an independent association between low preoperative lymphocyte level and poor postoperative outcomes following surgery for metastatic spine tumors. Although lymphopenia may be used to predict outcomes in other tumor-related surgeries, this metric may not hold a similar predictive capability in the population undergoing surgery for metastatic spine tumors. Further research into reliable prognostic tools is needed.

Performance Assessment of the American College of Surgeons Risk Calculator in Metastatic Spinal Tumor Surgery.

STUDY DESIGN: This was a retrospective cohort study. OBJECTIVE: The objective of this study was to assess the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) surgical risk calculator performance in patients undergoing surgery for metastatic spine disease. SUMMARY OF BACKGROUND DATA: Patients with spinal metastases may require surgical intervention for cord compression or mechanical instability. The ACS-NSQIP calculator was developed to assist surgeons with estimating 30-day postoperative complications based on patient-specific risk factors and has been validated within several surgical patient populations. MATERIALS AND METHODS: We included 148 consecutive patients at our institution who underwent surgery for metastatic spine disease between 2012 and 2022. Our outcomes were 30-day mortality, 30-day major complications, and length of hospital stay (LOS). Predicted risk, determined by the calculator, was compared with observed outcomes using receiver operating characteristic curves with area under the curve (AUC) and Wilcoxon signed-rank tests. Analyses were repeated using individual corpectomy and laminectomy Current Procedural Terminology (CPT) codes to determine procedure-specific accuracy. RESULTS: Based on the ACS-NSQIP calculator, there was good discrimination between observed and predicted 30-day mortality incidence overall (AUC=0.749), as well as in corpectomy cases (AUC=0.745) and laminectomy cases (AUC=0.788). Poor 30-day major complication discrimination was seen in all procedural cohorts, including overall (AUC=0.570), corpectomy (AUC=0.555), and laminectomy (AUC=0.623). The overall median observed LOS was similar to predicted LOS (9 vs. 8.5 d, P =0.125). Observed and predicted LOS were also similar in corpectomy cases (8 vs. 9 d; P =0.937) but not in laminectomy cases (10 vs. 7 d, P =0.012). CONCLUSIONS: The ACS-NSQIP risk calculator was found to accurately predict 30-day postoperative mortality but not 30-day major complications. The calculator was also accurate in predicting LOS following corpectomy but not laminectomy. While this tool may be utilized to predict risk short-term mortality in this population, its clinical value for other outcomes is limited.

Performance assessment and external validation of specific thresholds of total psoas muscle cross-sectional area as predictors of mortality in oncologic spine surgery for spinal metastases.

PURPOSE: The purpose of this study was to assess the utility of low muscle mass (LMM) in predicting 90-day and 12-month mortality after spinal tumor surgery. METHODS: We identified 115 patients operated on for spinal metastases between April 2012 and August 2022 who had available perioperative abdominal or lumbar spine CT scans and minimum 90-day follow-up. LMM was defined as a total psoas muscle cross-sectional area (TPA) at the L4 pedicle level less than 10.5 cm2 for men and less than 7.2 cm2 for women based on previously reported thresholds. A secondary analysis was performed by analyzing TPA as a continuous variable. The primary endpoint was 90-day mortality, and the secondary endpoint was 12-month mortality. Multivariate logistic regression analyses were performed. RESULTS: The 90-day mortality was 19% for patients without and 42% for patients with LMM (p = 0.010). After multivariate analysis, LMM was not independently associated with increased odds of 90-day mortality (odds ratio 2.16 [95% confidence interval 0.62 to 7.50]; p = 0.223). The 12-month mortality was 45% for patients without and 71% for patients with LMM (p = 0.024). After multivariate analysis, LMM was not independently associated with increased odds of 12-month mortality (OR 1.64 [95% CI 0.46 to 5.86]; p = 0.442). The secondary analysis showed no independent association between TPA and 90-day or 12-month mortality. CONCLUSION: Patients with LMM had higher rates of 90-day and 12-month mortality in our study, but this was not independent of other parameters such as performance status, hypoalbuminemia, or primary cancer type.

Selecting the lowest instrumented vertebra in a multilevel posterior cervical fusion across the cervicothoracic junction: a biomechanical investigation.

OBJECTIVE: Posterior cervical fusion is a common surgical treatment for patients with myeloradiculopathy or regional deformity. Several studies have found increased stresses at the cervicothoracic junction (CTJ) and significantly higher revision surgery rates in multilevel cervical constructs that terminate at C7. The purpose of this study was to investigate the biomechanical effects of selecting C7 versus T1 versus T2 as the lowest instrumented vertebra (LIV) in multisegmental posterior cervicothoracic fusion procedures. METHODS: Seven fresh-frozen cadaveric cervicothoracic spines (C2-L1) with ribs intact were tested. After analysis of the intact specimens, posterior rods and lateral mass screws were sequentially added to create the following constructs: C3-7 fixation, C3-T1 fixation, and C3-T2 fixation. In vitro flexibility tests were performed to determine the range of motion (ROM) of each group in flexion-extension (FE), lateral bending (LB), and axial rotation (AR), and to measure intradiscal pressure of the distal adjacent level (DAL). RESULTS: In FE, selecting C7 as the LIV instead of crossing the CTJ resulted in the greatest increase in ROM (2.54°) and pressure (29.57 pound-force per square inch [psi]) at the DAL in the construct relative to the intact specimen. In LB, selecting T1 as the LIV resulted in the greatest increase in motion (0.78°) and the lowest increase in pressure (3.51 psi) at the DAL relative to intact spines. In AR, selecting T2 as the LIV resulted in the greatest increase in motion (0.20°) at the DAL, while selecting T1 as the LIV resulted in the greatest increase in pressure (8.28 psi) in constructs relative to intact specimens. Although these trends did not reach statistical significance, the observed differences were most apparent in FE, where crossing the CTJ resulted in less motion and lower intradiscal pressures at the DAL. CONCLUSIONS: The present biomechanical cadaveric study demonstrated that a cervical posterior fixation construct with its LIV crossing the CTJ produces less stress in its distal adjacent discs compared with constructs with C7 as the LIV. Future clinical testing is necessary to determine the impact of this finding on patient outcomes.

Imaging score for differentiation of meningioma grade.

PURPOSE: We sought to establish a comprehensive imaging score indicating the likelihood of higher WHO grade meningiomas pre-operatively. METHODS: All surgical intracranial meningioma patients at our institution between 2014 and 2018 underwent retrospective chart review. Preoperative MRI sequences were reviewed, and imaging features were included in the score based on statistical and clinical significance. Point values for each significant feature were assigned based on the beta coefficients obtained from multivariate analysis. The imaging score was calculated by adding up the points, for a total score of 0 to 5. The predictive ability of the score to identify higher-grade meningiomas was evaluated. RESULTS: Ninety patients, 50% of whom had a postoperative diagnosis of WHO grade II meningioma, were included. The mean age for the population was 59.9 years and 70% were female. Tumor volume ≥ 36.0 cc was assigned 2 points, presence of irregular tumor borders was assigned 2 points, and presence of peritumoral edema was assigned 1 point. The probability of having a WHO grade II meningioma was 0% with a score of 0, 25.0% with a score of 1, 38.5% with a score of 2, 65.4% with a score of 3, and 83.3% with a score of 4 or greater. A threshold of ≥ 3 points achieved a recall of 0.80, precision of 0.73, F1-score of 0.77, accuracy of 0.76, and AUC of 0.82. CONCLUSION: The proposed imaging scoring system had good predictive capability for WHO grade II meningiomas with good discrimination and calibration. External validation is needed.

Are There Racial or Socioeconomic Disparities in Ambulatory Outcome or Survival After Oncologic Spine Surgery for Metastatic Cancer? Results From a Medically Underserved Center.

BACKGROUND: Disparities among patients with cancer are well documented. Recent studies suggest these disparities also affect patients undergoing metastatic spinal tumor surgery. However, it is unclear whether social factors are associated with ambulatory outcomes or overall survival. QUESTIONS/PURPOSES: In patients undergoing metastatic spinal tumor surgery, (1) Are race, Social Vulnerability Index (SVI) score, or insurance status associated with a lower likelihood of postoperative ambulation? (2) Are race, SVI score, or insurance status associated with shorter overall survival? METHODS: Between April 2012 and June 2021, we surgically treated 148 patients for metastatic cord compression or spinal mechanical instability because of cancer. Inclusion criteria were patients with complete demographic, social, oncologic, and follow-up data and patients who were followed until death or for at least 3 months postoperatively. Based on these criteria, 12% (18 of 148) were excluded because they had incomplete data and another 7% (11 of 148) were excluded because they were lost before the minimum study follow-up interval, leaving 80% (119) for analysis. Collected social data included self-reported race (White, Black, Hispanic or Latino, or other), SVI score, and primary insurance (Medicare, Medicaid, or private). The median age of the group was 62 years (interquartile range [IQR] 53 to 70 years), and 58% of patients were men (69 of 119). The race distribution was 45% Black (54 of 119), 32% Hispanic or Latino (38 of 119), 16% White (19 of 119), and 7% other (eight of 119). The median SVI score was 89.8 (IQR 73.8 to 98.5), and 74% of patients (88) were categorized as having high vulnerability. The insurance distribution was as follows: Medicare: 43%, Medicaid: 36%, and private insurance: 21%. The primary outcome variable was complete inability to ambulate postoperatively and the secondary outcome was median overall survival. Exploratory data analysis, univariate and multivariate logistic regression, and univariate and multivariate Cox regression analyses were performed. RESULTS: After controlling for race, SVI score, insurance status, primary cancer, and modified Bauer score, the only factor independently associated with postoperative nonambulation was preoperative nonambulatory status (odds ratio 59.3 [95% confidence interval (CI) 13.2 to 266.1]; p < 0.001). After controlling for variables such as performance status, BMI, primary cancer, modified Bauer score, and insurance status, factors independently associated with survival included Eastern Cooperative Oncology Group performance status (hazard ratio [HR] 1.4 [95% CI 1.1 to 2.0]; p = 0.03), prostate cancer (HR 0.4 [95% CI 0.1 to 0.9]; p = 0.03), and hematologic cancer (HR 0.3 [95% CI 0.1 to 0.8]; p = 0.02). Race, SVI score, and insurance status were not associated with overall survival. CONCLUSION: In this study, we found no difference in ambulatory outcome for patients based on their race, SVI score, or insurance status. Likewise, no differences in postoperative survival were found. These findings suggest that despite differences in presentation or short-term outcome reported in other investigations, the social factors we explored were not associated with the likelihood of a patient being nonambulatory postoperatively or shorter survival after spinal tumor surgery. Research studies that analyze race as a covariate of interest should take care to explore metrics of socioeconomic deprivation (such as the SVI score) to avoid drawing misleading conclusions. LEVEL OF EVIDENCE: Level III, therapeutic study.

An Artificial Neural Network Model for the Prediction of Perioperative Blood Transfusion in Adult Spinal Deformity Surgery.

Prediction of blood transfusion after adult spinal deformity (ASD) surgery can identify at-risk patients and potentially reduce its utilization and the complications associated with it. The use of artificial neural networks (ANNs) offers the potential for high predictive capability. A total of 1173 patients who underwent surgery for ASD were identified in the 2017-2019 NSQIP databases. The data were split into 70% training and 30% testing cohorts. Eighteen patient and operative variables were used. The outcome variable was receiving RBC transfusion intraoperatively or within 72 h after surgery. The model was assessed by its sensitivity, positive predictive value, F1-score, accuracy (ACC), and area under the curve (AUROC). Average patient age was 56 years and 63% were female. Pelvic fixation was performed in 21.3% of patients and three-column osteotomies in 19.5% of cases. The transfusion rate was 50.0% (586/1173 patients). The best model showed an overall ACC of 81% and 77% on the training and testing data, respectively. On the testing data, the sensitivity was 80%, the positive predictive value 76%, and the F1-score was 78%. The AUROC was 0.84. ANNs may allow the identification of at-risk patients, potentially decrease the risk of transfusion via strategic planning, and improve resource allocation.

Cigarette smoking and complications in elective thoracolumbar fusions surgery: An analysis of 58,304 procedures.

Study Design: This was retrospective cohort study. Purpose: The current investigation uses a large, multi-institutional dataset to compare short-term morbidity and mortality rates between current smokers and nonsmokers undergoing thoracolumbar fusion surgery. Overview of Literature: The few studies that have addressed perioperative complications following thoracolumbar fusion surgeries are each derived from small cohorts from single institutions. Materials and Methods: A retrospective study was conducted on thoracolumbar fusion patients in the American College of Surgeons National Surgical Quality Improvement Program database (2006-2016). The primary outcome compared the rates of overall morbidity, severe postoperative morbidity, infections, pneumonia, deep venous thrombosis (DVT), pulmonary embolism (PE), transfusions, and mortality in smokers and nonsmokers. Results: A total of 57,677 patients were identified. 45,952 (78.8%) were nonsmokers and 12,352 (21.2%) smoked within 1 year of surgery. Smokers had fewer severe complications (1.6% vs. 2.0%, P = 0.014) and decreased discharge to skilled nursing facilities (6.3% vs. 11.5%, P < 0.001) compared to nonsmokers. They had lower incidences of transfusions (odds ratio [OR] = 0.9, confidence interval [CI] = 0.8-1.0, P = 0.009) and DVT (OR = 0.7, CI = 0.5-0.9, P = 0.039) as well as shorter length of stay (LOS) (OR = 0.9, CI = 0.9-0.99, P < 0.001). They had a higher incidence of postoperative pneumonia (OR = 1.4, CI = 1.1-1.8, P = 0.002). There was no difference in the remaining primary outcomes between smoking and nonsmoking cohorts. Conclusions: There is a positive correlation between smoking and postoperative pneumonia after thoracolumbar fusion. The incidence of blood transfusions, DVT, and LOS was decreased in smokers. Early postoperative mortality, severe complications, discharge to subacute rehabilitation facilities, extubation failure, PE, SSI, and return to OR were not associated with smoking.

The Effect of a Multidisciplinary Spine Clinic on Time to Care in Patients with Chronic Back and/or Leg Pain: A Propensity Score-Matched Analysis.

Chronic back and leg pain are leading causes of disability worldwide. The purpose of this study was to compare the care in a unidisciplinary (USC) versus multidisciplinary (MSC) spine clinic, where patients are evaluated by different specialists during the same office visit. Adult patients presenting with a chief complaint of back and/or leg pain between June 2018 and July 2019 were assessed for eligibility. The main outcome measures included the first treatment recommendations, the time to treatment order, and the time to treatment occurrence. A 1:1 propensity score-matched analysis was performed on 874 patients (437 in each group). For all patients, the most common recommendation was physical therapy (41.4%), followed by injection (14.6%), and surgery (9.7%). Patients seen in the MSC were more likely to be recommended injection (p < 0.001) and less likely to be recommended surgery as first treatment (p = 0.001). They also had significantly shorter times to the injection order (log-rank test, p = 0.004) and the injection occurrence (log-rank test, p < 0.001). In this study, more efficient care for patients with back and/or leg pain was delivered in the MSC setting, which was evidenced by the shorter times to the injection order and occurrence. The impact of the MSC approach on patient satisfaction and health-related quality-of-life outcome measures warrants further investigation.

Beach Breaking Waves and Related Cervical Spine Injuries: A Level One Trauma Center Experience and Systematic Review.

OBJECTIVE: To analyze cervical spine injuries resulting from recreational activity in shallow ocean water amid high-energy breaking waves. METHODS: Single-center 10-year review of patients who sustained cervical injuries at the beach in Long Island, New York, USA. A systematic review following the PRISMA guidelines was also performed. RESULTS: Nineteen patients (age 17-79 years) sustained cervical injury from high-energy breaking waves while in shallow beach water. Six patients dived into a wave; 6 patients were struck by a large wave while standing upright; and 7 tumbled in the waves while engaged in nonspecified recreational activity. All 7 patients with subaxial cervical AO Spine Injury Score (AO-SIS) >10 had cervical spine injury with cord signal change and required operative management. Diving mechanism, AO-SIS >10, and cord signal change all predicted significant disability or death at 12 months (P < 0.01). The present study and 7 additional studies reporting on 534 patients (mean age, 45.4 years) were analyzed. Within the reported literature, most patients (94.2%) sustained a spinal cord injury. On long-term follow-up, an estimated 64.8% of patients had permanent neurologic injury and 12.5% had permanent quadriplegia. CONCLUSIONS: We offer the first description of cervical injuries sustained in water-related recreational activity using the AO-SIS. The morphology of injuries varied significantly and seemed to depend on body position and wave kinetic energy. Patients presenting with cervical injury in this setting and yielding AO-SIS >10 are likely to have poor functional recovery.

Comparison of three predictive scoring systems for morbidity in oncological spine surgery.

Estimating complications in oncological spine surgery is challenging. The objective of this study was to compare the accuracy of three scoring systems for predicting perioperative morbidity after surgery for spinal metastases. One-hundred and five patients who underwent surgery between 2013 and 2019 were included in this study. All patients had scores retrospectively calculated using the New England Spinal Metastasis Score (NESMS), Metastatic Spinal Tumor Frailty Index (MSTFI), and Anzuategui scoring systems. The main outcome measure was development of a medical complication (minor or major) within 30 days of surgery. The predictive ability for each system was assessed using receiver operating characteristic analysis and calculations of the area under the curve (AUC). The average age for all patients was 61 years and 61/105 patients (58.1%) were male. The most common primary tumor origins were hematologic (23.8%), prostate (16.2%), breast (14.3%), and lung (13.3%). The overall 30-day complication rate was 36.2% and the rate of major complications was 21.9%. Among all patients who underwent oncological spine surgery, the NESMS score had the highest AUC for 30-day overall (AUC 0.64; 95% CI, 0.53 - 0.75) and major morbidity (AUC 0.68; 95% CI, 0.54- 0.81) in our population. However, the accuracy did not meet the threshold for clinical utility. Future prospective validation of these systems in other populations is encouraged.

Predictive value of hypoalbuminemia and severe hypoalbuminemia in oncologic spine surgery.

STUDY DESIGN: Retrospective review of a prospectively collected national database. OBJECTIVE: To evaluate the predictive value of hypoalbuminemia on outcomes in surgical spine oncology patients. SUMMARY OF BACKGROUND DATA: It is well documented that patients with hypoalbuminemia (albumin <3.5) have significantly higher rates of surgical morbidity and mortality than patients with normal albumin (>3.5 g/dl). We evaluated outcomes for metastatic oncologic spine surgery patients based on pre-operative albumin levels. MATERIALS AND METHODS: Patients who underwent surgery for metastatic spine disease were identified in the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from 2006 to 2016. Three groups were established: patients with normal albumin (>3.5 g/dl), mild hypoalbuminemia (2.6 g/dl - 3.4 g/dl), and severe hypoalbuminemia (<=2.5 g/dl). A multivariate analysis was used to assess the association between albumin levels and mortality within 30 days of surgical intervention. RESULTS: A total of 700 patients who underwent surgery for metastatic spinal disease and had pre-operative albumin levels available were identified; 64.0% had normal albumin (>3.5 g/dl), 29.6% had mild hypoalbuminemia, and 6.4% had severe hypoalbuminemia. The overall 30-day mortality was 7.6% for patients with normal albumin, 15.9% for patients with mild hypoalbuminemia, and 44.4% for patients with severe hypoalbuminemia. On multivariate analysis, patients with mild hypoalbuminemia (OR 1.7 95% CI: 1.0-3.0 p = 0.05) and severe hypoalbuminemia (OR 6.2 95% CI: 2.8-13.5 p < 0.001) were more likely to expire within 30 days compared to patients with preoperative albumin above 3.5 g/dl. CONCLUSION: In this study, albumin level was found to be an independent predictor of 30-day mortality in patients who underwent operative intervention for metastatic spinal disease. Patients with severe hypoalbuminemia had a 7-fold increased risk when compared with those who had normal albumin. While these findings need to be validated by future studies, we believe they will prove useful for preoperative risk stratification and surgical decision-making.