Objectives: The aim was to compare medical malpractice outcomes among different types of spine surgery and identify predictors of litigation outcomes.Summary of Background Data: Spine surgery is highly litigious in the United States with data suggesting favorable outcomes for defendant surgeons. However, factor specific data and explanations for plaintiff verdicts are lacking.Methods: Westlaw legal database was queried for spine surgery malpractice outcomes from 2010 to 2019. Clinical data, reasons for litigation, and legal outcomes were tabulated. Statistical analysis was performed to identify factors associated with litigation outcomes.Results: A total of 257 cases were identified for inclusion. There were 98 noninstrumented and 148 instrumented cases; 110 singlelevel and 99 multilevel; 83 decompressions, 95 decompression and fusions, and 47 fusion only. In all, 182 (71%) resulted in a defendant verdict, 44 (17%) plaintiff verdict, and 31 (12%) settlement. Plaintiff verdicts resulted in payouts of $2.03 million, while settlements resulted in $1.11 million (P = 0.34). Common reasons for litigation were intraoperative error, hardware complication, and improper postoperative management. Cases were more likely to result for the plaintiff if postoperative cauda equina syndrome (55% vs. 26%, P < 0.01), a surgical site infection (46% vs. 27%, P = 0.03), or other catastrophic injury (40% vs. 26%, P = 0.03) occurred. Higher monetary awards were associated with multi versus single-level

These findings demonstrate that mAMPH exposure and withdrawal lead to steeper discounting of reward value by effort, an effect that is consistent with the effect of mAMPH on discounting by delay, and which may reflect an underlying shared mechanism.

In goal-directed pursuits, the basolateral amygdala (BLA) is critical in learning about changes in the value of rewards. BLA-lesioned rats show enhanced reversal learning, a task employed to measure the flexibility of response to changes in reward. Similarly, there is a trend for enhanced discrimination learning, suggesting that BLA may modulate formation of stimulus-reward associations. There is a parallel literature on the importance of serotonin (5HT) in new stimulus-reward and reversal learning. Recent postulations implicate 5HT in learning from punishment. Whereas, dopaminergic involvement is critical in behavioral activation and reinforcement, 5HT may be most critical for aversive processing and behavioral inhibition, complementary cognitive processes. Given these findings, a 5HT-mediated mechanism in BLA may mediate the facilitated learning observed previously. The present study investigated the effects of selective 5HT lesions in BLA using 5,7-dihydroxytryptamine (5,7-DHT) vs. infusions of saline (Sham) on discrimination, retention, and deterministic reversal learning. Rats were required to reach an 85% correct pairwise discrimination and single reversal criterion prior to surgery. Postoperatively, rats were then tested on the (1) retention of the pretreatment discrimination pair, (2) discrimination of a novel pair, and (3) reversal learning performance. We found statistically comparable preoperative learning rates between groups, intact postoperative retention, and unaltered novel discrimination and reversal learning in 5,7-DHT rats. These findings suggest that 5HT in BLA is not required for formation and flexible adjustment of new stimulus-reward associations when the strategy to efficiently solve the task has already been learned. Given the complementary role of orbitofrontal cortex in reward learning and its interconnectivity with BLA, these findings add to the list of dissociable mechanisms for BLA and orbitofrontal cortex in reward learning.

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Background: The wide range of clinical applications and controversial scientific evidence associated with platelet-rich plasma (PRP) therapy in musculoskeletal medicine requires an examination of the most commonly cited studies within this field. Purpose: To identify the 50 most cited articles on PRP, assess their study design, and determine any correlations between the number of citations and level of evidence (LoE) or methodological quality. Study Design: Cross-sectional study. Methods: The Web of Science database was queried to identify the top 50 most cited articles on PRP in orthopaedic surgery. Bibliometric characteristics, number of citations, and LoE were recorded. Methodological quality was evaluated using the Modified Coleman Methodology Score (MCMS), Methodological Index for Non-randomized Studies (MINORS), and Minimum Information for Studies Evaluating Biologics in Orthopaedics (MIBO). The Pearson correlation coefficient and Spearman correlation coefficient ( r S) were used to determine the degree of correlation between the number of citations or citation density and LoE, MCMS, MINORS score, and MIBO score. Student t tests were performed for 2-group comparisons. Results: The top 50 articles were published between 2005 and 2016 in 21 journals. The mean number of citations and citation density were 241 ± 94 (range, 151-625) and 23 ± 8, respectively, and the mean LoE was 2.44 ± 1.67, with 15 studies classified as LoE 1. The mean MCMS, MINORS score, and MIBO score were 66.9 ± 12.6, 16 ± 4.7, and 12.4 ± 3.7, respectively. No correlation was observed between the number of citations or citation density and LoE, MCMS, MINORS score, and MIBO score. A significant difference ( P = .02) was noted in LoE in articles from the United States (3.56 ± 1.7) versus outside the United States (2 ± 1.5). Seven of the 8 in vivo studies were published between 2005 and 2010, whereas 19 of the 25 clinical outcome investigations were published between 2011 and 2016. Studies that were published more recently were found to significantly correlate with number of citations ( r S = –0.38; P = .01), citation density ( r S = 0.36; P = .01), and higher LoE ( r S = 0.47; P = .01). Conclusion: The top 50 most cited articles on PRP consisted of high LoE and fair methodological quality. There was a temporal shift in research from in vivo animal studies toward investigations focused on clinical outcomes.

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Category: Ankle Arthritis; Ankle Introduction/Purpose: Ankle arthrodesis and total ankle replacement are the most commonly performed procedures for surgical management of ankle arthritis. Arthrodesis provides effective pain relief but the rate of complications after arthrodesis is higher as it is more commonly performed in patients with comorbidities that preclude ankle replacement. Accurately risk- stratifying patients who undergo ankle arthrodesis would be of great utility, given the significant cost and morbidity associated with developing major perioperative complications. There is a paucity of accurate prediction models that can be used to pre- operatively risk-stratify patients for ankle arthrodesis. We aim to develop a machine learning (ML) algorithm for prediction of major perioperative complication after ankle arthrodesis as well as compare its performance against traditional predictive models based on logistic regression. Methods: This is a retrospective cohort study of adult patients who underwent ankle arthrodesis at any non-federal California hospital between 2015 and 2017. The primary outcome was readmission within 30 days or major perioperative complication - venous thromboembolism within 30 days, myocardial infarction within 7 days, pneumonia within 7 days, systemic infection within 7 days, surgical site bleeding within 90 days, and wound complications within 90 days. We build ML and logistic regression models that span different classes of modeling approaches: XGBoost, AdaBoost, Gradient Boosting, and Random Forest. Discrimination and calibration were assessed using area under the receiver operating characteristic curve (AUROC) and Brier score, respectively. We utilize a partial dependence function to measure the importance of an individual feature by assessing the average effect in predicted risks when its value is altered. We rank the contribution of the included variables to the prediction of adverse outcomes. Results: A total of 1,084 patients met inclusion criteria for this study. There were 131 major complications or readmission (12.1%). The optimized XGBoost algorithm demonstrates higher discrimination (AUROC: 0.707 + 0.052) compared to LR (0.691 + 0.055). The receiver operating characteristic curves for the XGBoost and logistic regression models are visualized in Figure 1. XGBoost also outperforms the three other ML models. This model was well calibrated (Brier score: 0.103 + 0.001). The variables most important for the XGBoost model include diabetes, chronic kidney disease, implant complication, and major fracture. Five of the ten most important features for XGBoost were markedly less important for the traditional logistic regression model: male sex, prior hip fracture, cardiorespiratory failure, acute renal failure, and dialysis status. Conclusion: We report a ML algorithm for prediction of major perioperative complications after ankle arthrodesis. The optimized XGBoost model is well-calibrated and demonstrates superior risk prediction to logistic regression. This tool may identify and address potentially modifiable risk factors, helping to accurately risk-stratify patients and decrease likelihood of major complications. Notably, the predictors most important for XGBoost are different from those for logistic regression. This suggests that the superior discriminative capability of ML methods stems from their ability to capture complex non-linear relationships between variables that logistic regression is unable to detect.