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Background: Postoperative metrics are increasingly important in determining standards of quality for physicians and hospitals. Although complications following spinal surgery have been described, procedural and patient variables have yet to be incorporated into a predictive model of adverse-event occurrence. We sought to develop a predictive model of complication occurrence after spine surgery.Methods: We used longitudinal prospective data from a national claims database and developed a predictive model incorporating complication type and frequency of occurrence following spine surgery procedures. We structured our model to assess the impact of features such as preoperative diagnosis, patient comorbidities, location in the spine, anterior versus posterior approach, whether fusion had been performed, whether instrumentation had been used, number of levels, and use of bone morphogenetic protein (BMP). We assessed a variety of adverse events. Prediction models were built using logistic regression with additive main effects and logistic regression with main effects as well as all 2 and 3-factor interactions. Least absolute shrinkage and selection operator (LASSO) regularization was used to select features. Competing approaches included boosted additive trees and the classification and regression trees (CART) algorithm. The final prediction performance was evaluated by estimating the area under a receiver operating characteristic curve (AUC) as predictions were applied to independent validation data and compared with the Charlson comorbidity score.Results: The model was developed from 279,135 records of patients with a minimum duration of follow-up of 30 days. Preliminary assessment showed an adverse-event rate of 13.95%, well within norms reported in the literature. We used the first 80% of the records for training (to predict adverse events) and the remaining 20% of the records for validation. There was remarkable similarity among methods, with an AUC of 0.70 for predicting the occurrence of adverse events. The AUC using the Charlson comorbidity score was 0.61. The described model was more accurate than Charlson scoring (p < 0.01).Conclusions: We present a modeling effort based on administrative claims data that predicts the occurrence of complications after spine surgery.Clinical Relevance: We believe that the development of a predictive modeling tool illustrating the risk of complication occurrence after spine surgery will aid in patient counseling and improve the accuracy of risk modeling strategies. [ABSTRACT FROM AUTHOR]

Background: Spine trauma patients may represent a group for whom insurance fails to provide protection from catastrophic medical expenses, resulting in the transfer of financial burden onto individual families and public payers. This study compares the rate of insurance discontinuation for patients who underwent surgery for traumatic spine injury with and without spinal cord injury with the rate for matched control subjects. Methods: We used the MarketScan database to perform a retrospective cohort study of privately insured spine trauma patients who underwent surgery from 2006 to 2010. Kaplan-Meier survival analysis was used to assess the time to insurance discontinuation. Cox proportional-hazards regression was used to determine hazard ratios for insurance discontinuation among spine trauma patients compared with the matched control population. Results: The median duration of existing insurance coverage was 20.2 months for those with traumatic spinal cord injury, 25.6 months for those with traumatic spine injury without spinal cord injury, and 48.0 months for the matched control cohort (log-rank p < 0.0001). After controlling for multiple covariates, the hazard ratios for discontinuation of insurance were 2.02 (95% CI [confidence interval], 1.83 to 2.23) and 2.78 (95% CI, 2.31 to 3.35) for the trauma patients without and with spinal cord injury, respectively, compared with matched controls. Conclusions: Rates of insurance discontinuation are significantly higher for trauma patients with severe spine injury compared with the uninjured population, indicating that patients with disabling injuries are at increased risk for loss of insurance coverage. [ABSTRACT FROM AUTHOR]

Background: Usage of recombinant human bone morphogenetic protein (rhBMP) in anterior cervical discectomy and fusion (ACDF) procedures is controversial. Studies suggest increased rates of dysphagia, hematoma or seroma, and severe airway compromise in anterior cervical spine procedures using rhBMP. The purpose of the present study was to determine and describe national utilization trends and complication rates associated with rhBMP usage in anterior cervical spine procedures. Methods: The MarketScan database from 2006 to 2010 was retrospectively queried to identify 91,543 patients who underwent ACDF with or without cervical corpectomy. Patient selection and outcomes were ascertained with use of ICD- 9-CM (International Classification of Diseases, Ninth Revision, Clinical Modification) and CPT (Current Procedural Terminology) coding. A total of 3197 patients were treated with rhBMP intraoperatively. Mean follow-up was 588 days (interquartile range [IQR], 205 to 886 days) in the non-treated cohort and 591 days (IQR, 203 to 925 days) in the rhBMP-treated cohort. Multivariate logistic regression as well as propensity score analysis were used to evaluate the association of rhBMP usage with postoperative complications. Results: In propensity score-adjusted models, rhBMP usage was associated with an increased risk of any complication (odds ratio [OR] = 1.34, 95% confidence interval [CI] = 1.2 to 1.5) and specific complications such as hematoma or seroma (OR = 1.8, 95% CI = 1.4 to 2.3), dysphagia (OR = 1.3, 95% CI = 1.1 to 1.5), and any pulmonary complication (OR = 1.5, 95% CI = 1.2 to 1.8) within thirty days postoperatively. There were no significant differences in the rates of readmission, in-hospital mortality, referral to pain management, new malignancy, or reoperation between the two cohorts. Usage of rhBMP was associated with a mean increase of $5545 (19%) in total payments to the hospital and primary physician (p < 0.001). Conclusions: We found an increased overall rate of postoperative complications in patients receiving rhBMP for cervical spinal fusion procedures compared with patients not receiving rhBMP. Hematoma or seroma, pulmonary complications, and dysphagia were also more common in the rhBMP cohort. Usage of rhBMP in a case was associated with $311 greater payments to the surgeon and $4213 greater payments to the hospital. [ABSTRACT FROM AUTHOR]

Background: Intra-abdominal vascular injuries are rare during posterior lumbar spinal surgery, but they can result in major morbidity or mortality when they do occur. We are aware of no prior studies that have used prone patient positioning during magnetic resonance imaging for the purpose of characterizing the retroperitoneal iliac vasculature with respect to the intervertebral disc. The purpose of this study was to define the vascular anatomy adjacent to the lower lumbar spine with use of supine and prone magnetic resonance imaging.Methods: A prospective observational study included thirty patients without spinal abnormality who underwent supine and prone magnetic resonance imaging without abdominal compression. The spinal levels of the aortic bifurcation and confluence of the common iliac veins were identified. The proximity of the anterior iliac vessels to the anterior and posterior aspects of the anulus fibrosus in sagittal and coronal planes was measured by two observers, and interobserver reliability was calculated.Results: The aortic bifurcation and confluence of the common iliac veins were most commonly at the level of the L4 vertebral body and migrated cranially with prone positioning. The common iliac vessels were closer to the anterior aspect of the intervertebral disc and to the midline at L4-L5 as compared with L5-S1, consistent with the bifurcation at the L4 vertebral body. Prone positioning resulted in greater distances between the disc and iliac vessels at L4-L5 and L5-S1 by an average of 3 mm. The position of the anterior aspect of the anulus with respect to each iliac vessel demonstrated substantial variation between subjects. The intraclass correlation coefficient for measurement of vessel position exceeded 0.9, demonstrating excellent interobserver reliability.Conclusions: This study confirmed the L4 level of the aortic bifurcation and iliac vein coalescence but also demonstrated substantial mobility of the great vessels with positioning. Supine magnetic resonance imaging will underestimate the proximity of the vessels to the intervertebral disc. Large interindividual variation in the location of vasculature was noted, emphasizing the importance of careful study of the location of the retroperitoneal vessels on a case-by-case basis. [ABSTRACT FROM AUTHOR]