Colleges and Crime-Comparing Homicide and Suicide Rates Among College Towns and Their Counterparts.

INTRODUCTION: To investigate differences in homicide and suicide rates across college town status and determine whether college towns were predisposed to changes in rates over time. METHODS: We analyzed county-level homicide and suicide rates (total and by firearm) across college town status using 2015-2019 CDC death certificate data and data from the American Communities Project. RESULTS: Population-level homicide rates were similar across college town status, but younger age groups were at increased risk for firearm homicide and total homicide in college towns. College town status was associated with lower population-level firearm suicide rates, but individuals aged less than 18 y were at increased risk for total and firearm suicide. Finally, college towns were not classified as outliers for changes in either firearm homicide or suicide rates over time. CONCLUSIONS: College towns had similar homicide rates and significantly lower firearm suicide rates than other counties; however, individuals aged less than 18 y were at increased risk for both outcomes. The distinctive demographic, social, economic, and cultural features of college towns may contribute to differing risk profiles among certain age groups, thus may also be amenable to focused prevention efforts.

Adolescent Gun Violence Shows an Age Group to Focus Trauma Prevention.

INTRODUCTION: Gun violence continues to escalate in America's urban areas. Peer groups of gun wound victims are potential targets for violence prevention initiatives; identification of this cohort is pivotal to efficient deployment strategies. We hypothesize a specific age at which the incidence of penetrating trauma increases significantly in adolescence, below which should be the focus on future trauma prevention. METHODS: Adolescent trauma patients with gunshot wounds seen from July 2011 through June 2021 at a well-established, urban, academic level 1 trauma center were reviewed retrospectively and grouped by age. A linear regression and repeated measured analysis of variance evaluated the change in gunshot wound victims over this time, grouped by age. Demographics were extrapolated, and standard statistical analysis was performed. RESULTS: A total of 1304 adolescent trauma patients were included. Those aged 15 y and under had an unchanged incidence of gunshot wounds. However, those aged 16 y and more experienced the majority of increased gun violence; 92% were Black and 90% were male with a mortality of 12%. Adolescents aged 15 y and below were 95% Black and 84% male, with a mortality of 18%. CONCLUSIONS: Primary prevention efforts to mitigate gun violence should be focused on adolescents below 16 y of age. Prevention of gun violence should include community outreach efforts directed toward middle school-aged children and younger, hoping to decrease the incidence of injury due to gun violence in older adolescents in the future.

Persistent Blunting of Penumbral Leukocyte Mobilization by Beta Blockade Administered for Two Weeks After Traumatic Brain Injury.

INTRODUCTION: Beta-blockers (BB) after traumatic brain injury (TBI) accelerate cognitive recovery weeks after injury. BBs also inhibit leukocyte (LEU) mobilization to the penumbral blood brain barrier (BBB) 48-h after TBI. It is unclear whether the latter effects persist longer and accompany the persistent cognitive improvement. We hypothesized that 2 wk of BB after TBI reduce penumbral BBB leukocyte-endothelial interactions. METHODS: Thirty CD1 mice underwent TBI (controlled cortical impact, CCI: 6 m/s velocity, 1 mm depth, 3 mm diameter) or sham craniotomy followed by i.p. saline (NS) or propranolol (1, 2, 4 mg/kg) every 12 h for 14 d. On day 14, in vivo pial intravital microscopy visualized endothelial-LEU interactions and BBB microvascular leakage. Day 14 Garcia neurological test scores and animal weights were compared to preinjury levels reflecting concurrent clinical recovery. RESULTS: LEU rolling was greatest in CCI + NS when compared to sham (P = 0.03). 4 mg/kg propranolol significantly reduced postCCI LEU rolling down to uninjured sham levels (P = 0.03). LEU adhesion and microvascular permeability were not impacted at this time interval. Untreated injured animals (CCI + NS) scored lower Garcia neurological test and greater weight loss recovery at day 14 when compared to preinjury (P < 0.05). Treatment with higher doses of propranolol (2, 4 mg/kg), improved weight loss recovery (P < 0.001). CONCLUSIONS: LEU rolling alone, was influenced by BB therapy 14 d after TBI suggesting that certain penumbral neuroinflammatory cellular effects of BB therapy after TBI persist up to 2 wk after injury potentially explaining the pervasive beneficial effects of BBs on learning and memory.

Overcoming Barriers: Sex Disparity in Surgeon Ergonomics.

BACKGROUND: Musculoskeletal discomfort is widely experienced by surgeons across multiple surgical specialties. Developing technologies and new minimally invasive techniques add further complexity and ergonomic stressors. These stressors differentially affect male and female surgeons, but little is known about the role these sex disparities play in surgical ergonomic stress. We reviewed existing literature to better understand how ergonomic stress varies between male and female surgeons. STUDY DESIGN: A literature search was performed via PubMed including but not limited to the following topics: ergonomics, surgeons, female surgeons, women surgeons, pregnancy, and operating room. A review of available quantitative data was performed. RESULTS: Female surgeons endure more pronounced ergonomic discomfort than their male counterparts, with added ergonomic stress associated with pregnancy. CONCLUSIONS: A 4-fold method is proposed to overcome ergonomic barriers, including (1) improved education on prevention and treatment of ergonomic injury for active surgeons and trainees, (2) increased departmental and institutional support for ergonomic solutions for surgeons, (3) partnerships with industry to study innovative ergonomic solutions, and (4) additional research on the nature of surgical ergonomic challenges and the differential effects of surgical ergonomics on female surgeons.

Delayed tranexamic acid after traumatic brain injury impedes learning and memory: Early tranexamic acid is favorable but not in sham animals.

BACKGROUND: Early but not late tranexamic acid (TXA) after TBI preserves blood-brain-barrier integrity, but it is unclear if and how dose timing affects cognitive recovery beyond hours postinjury. We hypothesized that early (1 hour post-TBI) but not late (24 hours post-TBI) TXA administration improves cognitive recovery for 14 days. METHODS: CD1 male mice (n = 25) were randomized to severe TBI (injury [I], by controlled cortical impact) or sham craniotomy (S) followed by intravenous saline at 1 hour (placebo [P1]) or 30 mg/kg TXA at 1 hour (TXA1) or 24 hours (TXA24). Daily body weights, Garcia Neurological Test scores, brain/lung water content, and Morris water maze exercises quantifying swimming traffic in the platform quadrant (zone [Z] 1) and platform area (Z5) were recorded for up to 14 days. RESULTS: Among injured groups, I-TXA1 demonstrated fastest weight gain for 14 days and only I-TXA1 showed rapid (day 1) normalization of Garcia Neurological Test ( p = 0.01 vs. I-P1, I-TXA24). In cumulative spatial trials, compared with I-TXA1, I-TXA24 hindered learning (distance to Z5 and % time in Z1, p < 0.05). Compared with I-TXA1, I-TXA24 showed poorer memory with less Z5 time (0.51 vs. 0.16 seconds, p < 0.01) and Z5 crossing frequency. Unexpectedly, TXA in uninjured animals (S-TXA1) displayed faster weight gain but inferior learning and memory. CONCLUSION: Early TXA appears beneficial for cognitive and behavioral outcomes following TBI, although administration 24 hours postinjury consistently impairs cognitive recovery. Tranexamic acid in sham animals may lead to adverse effects on cognition.

Daily quetiapine after severe TBI improves learning and memory.

BACKGROUND: Traumatic brain injury (TBI) induces cognitive deficits driven by neuroinflammation and cerebral edema. The commonly used atypical antipsychotic, quetiapine (QTP), has been recently shown to improve post-TBI outcomes. We hypothesized that QTP would thereby improve animal learning and memory 2 weeks after severe TBI. METHODS: CD1 male mice (n = 35) underwent severe TBI (controlled cortical impact, injury, I) or sham craniotomy (S), followed by BID saline (P, placebo) or QTP (10 or 20 mg/kg, IP) for 2 weeks. Animals underwent Morris Water Maze (MWM) exercises to gauge spatial learning and memory. The distance and time required for swimming animals to reach the platform area (Zone 5, Z5) located in quadrant 1 (Zone 1, Z1) was calculated from digital video recordings analyzed using Ethovision software. Animal bodyweights were recorded daily and on day 14, injured cerebral hemispheres were procured for edema determination (wet-to-dry ratio). Intergroup differences were evaluated with ANOVA/Bonferroni correction (p < 0.05). RESULTS: On day 14, animal weight loss recovery was lowest in I + P compared to I + QTP20 and I + QTP10 (p ≤ 0.01 for either). Cerebral edema was greatest in I + P, and only significantly decreased in I + QTP20 (p < 0.05). Both QTP doses similarly improved spatial learning by significantly reducing latency time and travel distance to target zones (p < 0.05). In probe memory trials, only I + QTP20 and not I + QTP10 significantly favored animal reaching or crossing into target zones (p < 0.05). CONCLUSION: Post-TBI QTP reduces brain edema and improves spatial learning and memory with a potential dose dependence impact benefiting memory up to 14 days. These data suggest an unanticipated QTP benefit following brain injury that should be specifically explored.

Propensity weighted analysis of chemical venous thromboembolism prophylaxis agents in isolated severe traumatic brain injury: An EAST sponsored multicenter study.

BACKGROUND: In patients with severe traumatic brain injury (TBI), clinicians must balance preventing venous thromboembolism (VTE) with the risk of intracranial hemorrhagic expansion (ICHE). We hypothesized that low molecular weight heparin (LMWH) would not increase risk of ICHE or VTE as compared to unfractionated heparin (UH) in patients with severe TBI. METHODS: Patients ≥ 18 years of age with isolated severe TBI (AIS ≥ 3), admitted to 24 level I and II trauma centers between January 1, 2014 to December 31, 2020 and who received subcutaneous UH and LMWH injections for chemical venous thromboembolism prophylaxis (VTEP) were included. Primary outcomes were VTE and ICHE after VTEP initiation. Secondary outcomes were mortality and neurosurgical interventions. Entropy balancing (EBAL) weighted competing risk or logistic regression models were estimated for all outcomes with chemical VTEP agent as the predictor of interest. RESULTS: 984 patients received chemical VTEP, 482 UH and 502 LMWH. Patients on LMWH more often had pre-existing conditions such as liver disease (UH vs LMWH 1.7 % vs. 4.4 %, p = 0.01), and coagulopathy (UH vs LMWH 0.4 % vs. 4.2 %, p < 0.001). There were no differences in VTE or ICHE after VTEP initiation. There were no differences in neurosurgical interventions performed. There were a total of 29 VTE events (3 %) in the cohort who received VTEP. A Cox proportional hazards model with a random effect for facility demonstrated no statistically significant differences in time to VTE across the two agents (p = 0.44). The LMWH group had a 43 % lower risk of overall ICHE compared to the UH group (HR = 0.57: 95 % CI = 0.32-1.03, p = 0.062), however was not statistically significant. CONCLUSION: In this multi-center analysis, patients who received LMWH had a decreased risk of ICHE, with no differences in VTE, ICHE after VTEP initiation and neurosurgical interventions compared to those who received UH. There were no safety concerns when using LMWH compared to UH. LEVEL OF EVIDENCE: Level III, Therapeutic Care Management.

Penetrating trauma in urban women: patterns of injury and violence.

BACKGROUND: Penetrating trauma is known to occur with less frequency in women than in men, and this difference has resulted in a lack of characterization of penetrating injury patterns involving women. We hypothesized that the nature of penetrating injury differs significantly by gender and that these injuries in women are associated with important psychosocial and environmental factors. MATERIALS AND METHODS: A level 1 urban trauma center registry was queried for all patients with penetrating injuries from 2002-2010. Patient and injury variables (demographics and mechanism of injury) were abstracted and compared between genders; additional social and psychiatric histories and perpetrator information were collected from the records of admitted female patients. RESULTS: Injured women were more likely to be Caucasian, suffer stab wounds instead of gunshot wounds, and present with a higher blood alcohol level than men. Compared with women with gunshot wounds, those with stab wounds were three times more likely to report a psychiatric or intimate partner violence history. Women with self-inflicted injuries had a significantly greater incidence of prior penetrating injury and psychiatric and criminal history. Male perpetrators outnumbered female perpetrators; patients frequently not only knew their perpetrator but also were their intimate partners. Intimate partner violence and random cross-fire incidents each accounted for about a quarter of injuries observed. CONCLUSIONS: Penetrating injuries in women represent a nonnegligible subset of injuries seen in urban trauma centers. Psychiatric and social risk factors for violence play important roles in these cases, particularly when self-infliction is suspected. Resources allocated for urban violence prevention should proportionately reflect the particular patterns of violence observed in injured women.

Patients with uncontrolled components of metabolic syndrome have increased risk of complications following total joint arthroplasty.

Metabolic syndrome (MetS)-a diagnostic grouping of diabetes, dyslipidemia, hypertension, and obesity-has been indicated as a risk factor for perioperative complications following total joint arthroplasty (TJA). This study investigates the impact of MetS on perioperative complications, specifically the importance of controlling MetS components. One hundred thirty-three patients undergoing TJA with all four components of MetS were identified. They were matched one-to-one with patients without MetS. Control of diabetes, dyslipidemia, and hypertension was assessed. Thirty-five patients with MetS were found to have at least a single uncontrolled component. The complication rates were 49%, 8%, and 8% for uncontrolled MetS, controlled MetS, and no MetS, respectively. Multivariate analysis confirmed independent associations between control of MetS components and both perioperative complications and length of stay. Both surgeons and patients should be aware of the substantial risk of dangerous complications following TJA in patients with uncontrolled metabolic syndrome.

Risk factors for early mortality following modern total hip arthroplasty.

The aim of this study was to evaluate the incidence of early mortality and identify risk factors for early death following modern uncemented THA. Between 2000 and 2006, we identified patients who died within 90days of THA. Demographics, comorbidities, laboratory studies, and complications were analyzed as risk factors for mortality. 38 of 8261 patients undergoing THA (0.46%) died within 90days postoperatively. Of these, 26% were due to myocardial infarction. Multivariate analysis revealed Charlson index >3, peripheral vascular disease, elevated postoperative glucose, and abnormal postoperative cardiac studies as independent predictors of early mortality following THA. Caution should be taken in patients with increased comorbidities, PVD, perioperative hyperglycemia, and impaired renal function in order to reduce mortality following THA.

Early posttraumatic brain injury tranexamic acid prevents blood-brain barrier hyperpermeability and improves surrogates of neuroclinical recovery.

BACKGROUND: Tranexamic acid (TXA) given early, but not late, after traumatic brain injury (TBI) appears to improve survival. This may be partly related to TXA-driven profibrinolysis and increased leukocyte (LEU)-mediated inflammation when administered late post-injury. We hypothesized that early TXA (1 hour post-TBI), blunts penumbral, blood-brain barrier (BBB) leukocyte-endothelial cell (LEU-EC) interactions and microvascular permeability, in vivo when compared with late administration (24 hours post-TBI). METHODS: CD1 male mice (n = 35) were randomized to severe TBI (injury by controlled cortical impact; injury: velocity, 6 m/s; depth, 1 mm; diameter, 3 mm) or sham craniotomy followed by intravenous saline (placebo) at 1 hour, or TXA (30 mg/kg) at 1 hour or 24 hours. At 48 hours, in vivo pial intravital microscopy visualized live penumbral LEU-EC interactions and BBB microvascular fluorescent albumin leakage. Neuroclinical recovery was assessed by the Garcia Neurological Test (motor, sensory, reflex, and balance assessments) and body weight loss recovery at 1 and 2 days after injury. Analysis of variance with Bonferroni correction assessed intergroup differences ( p < 0.05). RESULTS: One-hour, but not 24-hour, TXA improved Garcia Neurological Test performance on day 1 post-TBI compared with placebo. Both 1 hour and 24 hours TXA similarly improved day 1 weight loss recovery, but only 1 hour TXA significantly improved weight loss recovery on day 2 compared with placebo ( p = 0.04). No intergroup differences were found in LEU rolling or adhesion between injured animal groups. Compared with untreated injured animals, only TXA at 1 hour reduced BBB permeability. CONCLUSION: Only early post-TBI TXA consistently improves murine neurological recovery. Tranexamic acid preserves BBB integrity but only when administered early. This effect appears independent of LEU-EC interactions and demonstrates a time-sensitive effect that supports only early TXA administration.

Higher center volume is significantly associated with lower mortality in trauma patients with shock.

INTRODUCTION: Injured patients presenting in shock are at high risk of mortality despite numerous efforts to improve resuscitation. Identifying differences in outcomes among centers for this population could yield insights to improve performance. We hypothesized that trauma centers treating higher volumes of patients in shock would have lower risk-adjusted mortality. METHODS: We queried the Pennsylvania Trauma Outcomes Study from 2016 to 2018 for injured patients ≥16 years of age at Level I&II trauma centers who had an initial systolic blood pressure (SBP) of <90 mmHg. We excluded patients with critical head injury (abbreviated injury score [AIS] head ≥5) and patients coming from centers with a shock patient volume of ≤10 for the study period. The primary exposure was tertile of center-level shock patient volume (low, medium, or high volume). We compared risk-adjusted mortality by tertile of volume using multivariable Cox proportional hazards model incorporating age, injury severity, mechanism, and physiology. RESULTS: Of 1,805 included patients at 29 centers, 915 (50.7%) died. The median annual shock trauma patient volume was 9 patients for low volume centers, medium 19.5, and high 37. Median ISS was higher at high volume compared to low volume centers (22 vs 18, p <0.001). Raw mortality was 54.9% at high volume centers, 46.7% for medium, and 42.9% for low. Time elapsed from arrival to emergency department (ED) to the operating room (OR) was lower at high volume than low volume centers (median 47 vs 78 min) p = 0.003. In adjusted analysis, hazard ratio for high volume centers (referenced to low volume) was 0.76 (95% CI 0.59-0.97, p = 0.030). CONCLUSION: After adjusting for patient physiology and injury characteristics, center-level volume is significantly associated with mortality. Future studies should seek to identify key practices associated with improved outcomes in high-volume centers. Furthermore, shock patient volume should be considered when new trauma centers are opened.

Contemporary management and outcomes of penetrating colon injuries: Validation of the 2020 AAST Colon Organ Injury Scale.

INTRODUCTION: The American Association for the Surgery of Trauma Colon Organ Injury Scale (OIS) was updated in 2020 to include a separate OIS for penetrating colon injuries and included imaging criteria. In this multicenter study, we describe the contemporary management and outcomes of penetrating colon injuries and hypothesize that the 2020 OIS system correlates with operative management, complications, and outcomes. METHODS: This was a retrospective study of patients presenting to 12 Level 1 trauma centers between 2016 and 2020 with penetrating colon injuries and Abbreviated Injury Scale score of <3 in other body regions. We assessed the association of the new OIS with surgical management and clinical outcomes and the association of OIS imaging criteria with operative criteria. Bivariate analysis was done with χ 2 , analysis of variance, and Kruskal-Wallis, where appropriate. Multivariable models were constructed in a stepwise selection fashion. RESULTS: We identified 573 patients with penetrating colon injuries. Patients were young and predominantly male; 79% suffered a gunshot injury, 11% had a grade V destructive injury, 19% required ≥6 U of transfusion, 24% had an Injury Severity Score of >15, and 42% had moderate-to-large contamination. Higher OIS was independently associated with a lower likelihood of primary repair, higher likelihood of resection with anastomosis and/or diversion, need for damage-control laparotomy, and higher incidence of abscess, wound infection, extra-abdominal infections, acute kidney injury, and lung injury. Damage control was independently associated with diversion and intra-abdominal and extra-abdominal infections. Preoperative imaging in 152 (27%) cases had a low correlation with operative findings ( κ coefficient, 0.13). CONCLUSION: This is the largest study to date of penetrating colon injuries and the first multicenter validation of the new OIS specific to these injuries. While imaging criteria alone lacked strong predictive value, operative American Association for the Surgery of Trauma OIS colon grade strongly predicted type of interventions and outcomes, supporting use of this grading scale for research and clinical practice. LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level III.

Early VTE prophylaxis in severe traumatic brain injury: A propensity score weighted EAST multicenter study.

BACKGROUND: Patients with traumatic brain injury (TBI) are at high risk of venous thromboembolism events (VTE). We hypothesized that early chemical VTE prophylaxis initiation (≤24 hours of a stable head CT) in severe TBI would reduce VTE without increasing risk of intracranial hemorrhage expansion (ICHE). METHODS: A retrospective review of adult patients 18 years or older with isolated severe TBI (Abbreviated Injury Scale score, ≥ 3) who were admitted to 24 Level I and Level II trauma centers from January 1, 2014 to December 31 2020 was conducted. Patients were divided into those who did not receive any VTE prophylaxis (NO VTEP), who received VTE prophylaxis ≤24 hours after stable head CT (VTEP ≤24) and who received VTE prophylaxis >24 hours after stable head CT (VTEP>24). Primary outcomes were VTE and ICHE. Covariate balancing propensity score weighting was utilized to balance demographic and clinical characteristics across three groups. Weighted univariate logistic regression models were estimated for VTE and ICHE with patient group as predictor of interest. RESULTS: Of 3,936 patients, 1,784 met inclusion criteria. Incidences of VTE was significantly higher in the VTEP>24 group, with higher incidences of DVT in the group. Higher incidences of ICHE were observed in the VTEP≤24 and VTEP>24 groups. After propensity score weighting, there was a higher risk of VTE in patients in VTEP >24 compared with those in VTEP≤24 (odds ratio, 1.51; 95% confidence interval, 0.69-3.30; p = 0.307), however was not significant. Although, the No VTEP group had decreased odds of having ICHE compared with VTEP≤24 (odds ratio, 0.75; 95% confidence interval, 0.55-1.02, p = 0.070), the result was not statistically significant. CONCLUSION: In this large multi-center analysis, there were no significant differences in VTE based on timing of initiation of VTE prophylaxis. Patients who never received VTE prophylaxis had decreased odds of ICHE. Further evaluation of VTE prophylaxis in larger randomized studies will be necessary for definitive conclusions. LEVEL OF EVIDENCE: Therapeutic Care Management; Level III.

Mark B. Coventry Award: synovial C-reactive protein: a prospective evaluation of a molecular marker for periprosthetic knee joint infection.

BACKGROUND: C-reactive protein (CRP) serum assays are a standard element of the diagnostic workup for periprosthetic joint infection (PJI). However, because CRP is a marker for systemic inflammation, this test is not specific to PJI. QUESTIONS/PURPOSES: Our purpose was to assess whether synovial fluid and serum assays alone could differentiate between infected and uninfected revision knee arthroplasties and to determine which of these methods had the greatest diagnostic accuracy. METHODS: We collected synovial fluid specimens from 66 patients undergoing revision total knee arthroplasty. Patients were judged uninfected or infected by standardized criteria. Synovial CRP levels were measured using an individual CRP assay (15 samples; 10 infected, five uninfected) and a multiplex immunoassay platform (59 samples; 25 infected, 34 uninfected). Results from preoperative standard serum CRP assays conducted were also collected (55 samples; 25 infected, 30 uninfected). Sensitivity, specificity, and receiver operating characteristic curve analyses were performed for each assay with a diagnosis of infection based on previously established criteria. RESULTS: Synovial CRP concentrations differed between infected and uninfected joints in the multiplex and serum analyses. The area under the curve was 0.84 for the individual assay, 0.91 for the multiplex assay, and 0.88 for the serum CRP assay. Sensitivity and specificity were 70.0% and 100.0% for the individual enzyme-linked immunosorbent assay, 84.0% and 97.1% for the multiplex assay, and 76.0% and 93.3% for the serum CRP assay. CONCLUSIONS: An assay measuring CRP in synovial fluid may be more accurate in diagnosing PJI than the standard serum CRP assay. We believe such an assay holds promise as a new diagnostic marker for PJI.

Overdiagnosis of pulmonary embolism: evaluation of a hypoxia algorithm designed to avoid this catastrophic problem.

BACKGROUND: We observed a substantial increase in the incidence of pulmonary embolism (PE) after total joint arthroplasty (TJA) when multidetector computerized tomography (MDCT) replaced ventilation-perfusion (V/Q) scans as the diagnostic modality of choice. We questioned whether this resulted from the detection of clinically unimportant PE with the more sensitive MDCT and in 2007 instituted a hypoxia protocol to enhance the detection of PE. QUESTIONS/PURPOSES: We determined whether this new hypoxia protocol increased the specificity of our workups for suspected clinically important PE in the immediate postoperative period without affecting patient morbidity and mortality. PATIENTS AND METHODS: We compared the frequency of MDCT, V/Q scan and total investigations, incidence of PE, and overall mortality rates in the 3 years prior (January 2003 to December 2006) and 2 years after (January 2007 to November 2009) the implementation of the algorithm. RESULTS: After instituting the protocol, we observed a trend toward a decrease in the number of patients worked up for PE (4.6 to 4.0 per 100 TJAs, 13.5% decrease). At the same time, there was an increase in the percent of positive findings of PE per workup for PE (23-33 positive PEs per 100 patients, 40.5% increase). All-cause mortality rates decreased for the 30-day period (3.1 to 1.4 per 1000 TJAs, 53.5% decrease) and the 90-day period (5.0 to 2.6 per 1000 TJAs, 48.3% decrease). CONCLUSIONS: With the implementation of this algorithm, the specificity of our management of postoperative hypoxia and suspected clinically important PE improved without affecting patient morbidity or mortality.

Operative trauma volume is not related to risk-adjusted mortality rates among Pennsylvania trauma centers.

BACKGROUND: Higher center-level operative volume is associated with lower mortality after complex elective surgeries, but this relationship has not been robustly demonstrated for operative trauma. We hypothesized that trauma centers in Pennsylvania with higher operative trauma volumes would have lower risk-adjusted mortality rates than lower volume institutions. METHODS: We queried the Pennsylvania Trauma Outcomes Study database (2017-2019) for injured patients 18 years or older at Level I and II trauma centers who underwent an International Classification of Diseases, Tenth Revision (ICD-10), procedure code -defined operative procedure within 6 hours of admission. The primary exposure was tertile of center-level operative volume. The primary outcome of interest was inpatient mortality. We entered factors associated with mortality in univariate analysis (age, injury severity, mechanism, physiology) into multivariable logistic regression models with tertiles of volume accounting for center-level clustering. We conducted secondary analyses varying the form of the association between the volume and mortality to including dichotomous and fractional polynomial models. RESULTS: We identified 3,650 patients at 29 centers meeting the inclusion criteria. Overall mortality was 15.9% (center-level range, 6.7-34.2%). Operative procedure types were cardiopulmonary (7.3%), vascular (20.1%), abdominopelvic (24.3%), and multiple (48.3%). The mean annual operative volume over the 3 years of data was 10 to 21 operations for low-volume centers, 22 to 47 for medium-volume centers, and 47 to 158 for high-volume centers. After controlling for patient demographics, physiology, and injury characteristics, there was no significant difference in mortality between highest and lowest tertile centers (odds ratio, 0.92; confidence interval, 0.57-1.49). Secondary analyses similarly demonstrated no relationship between center operative volume and mortality in key procedure subgroups. CONCLUSION: In a mature trauma system, we found no association between center-level operative volume and mortality for patients who required early operative intervention for trauma. Efforts to standardize the care of seriously injured patients in Pennsylvania may ensure that even lower-volume centers are prepared to generate satisfactory outcomes. LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level III.

Rising incidence of interpersonal violence in Pennsylvania during COVID-19 stay-at home order.

BACKGROUND: The coronavirus disease 2019 pandemic and associated policies have had important downstream consequences for individuals, communities, and the healthcare system, and they appear to have been accompanied by rising interpersonal violence. The objective of this study was to evaluate the incidence of injuries owing to interpersonal violence after implementation of a statewide stay-at-home order in Pennsylvania in March 2020. METHODS: Using the Pennsylvania Trauma Outcome Study registry, we conducted a retrospective cohort study of patients with gunshot wounds, stab wounds, and blunt assault-related injuries attributable to interpersonal violence treated at Pennsylvania trauma centers from March 16 to July 31 of 2018, 2019, and 2020. RESULTS: There were fewer total trauma admissions in 2020 (17,489) vs 2018 (19,290) and 2019 (19,561). Gunshot wounds increased in 2020 to 737 vs 647 for 2019 and 565 for 2018 (P = .028), whereas blunt assault injuries decreased (P = .03). In all time periods, interpersonal violence primarily impacted urban counties. African American men were predominantly affected by gunshot wounds and stab wounds, whereas Caucasian men were predominantly affected by blunt assault injuries. There were more patients with substance abuse disorders and positive drug screens during coronavirus disease than in comparison periods: (stab wound population 52.3% vs 33.9% vs 45.9%, coronavirus disease era vs 2018 vs 2019, respectively P = .0001), (blunt assault injury population 41.4% vs 33.1% vs 33.5%, coronavirus disease era vs 2018 vs 2019, respectively P < .0001). There was no correlation between the incidence of interpersonal violence and coronavirus disease 2019 rates at the county level. CONCLUSION: The implementation of a stay-at-home order was accompanied by rising incidence of gunshot and stab wound injuries in Pennsylvania. Preparedness for future resurgences of coronavirus disease 2019 and other pandemics calls for plans to address injury prevention, recidivism, and access to mental health and substance abuse prevention services.

Beta blockade in TBI: Dose-dependent reductions in BBB leukocyte mobilization and permeability in vivo.

BACKGROUND: Traumatic brain injury (TBI) is accompanied by a hyperadrenergic catecholamine state that can cause penumbral neuroinflammation. Prospective human studies demonstrate improved TBI survival with beta blockade (bb), although mechanisms remain unclear. We hypothesized that deranged post-TBI penumbral blood brain barrier (BBB) leukocyte mobilization and permeability are improved by bb. METHODS: CD1 male mice (n = 64) were randomly assigned to severe TBI-controlled cortical impact: 6 m/s velocity, 1 mm depth, 3 mm diameter-or sham craniotomy, and IP injection of either saline or propranolol (1, 2, or 4 mg/kg) every 12 hours for 2 days. At 48 hours, in vivo pial intravital microscopy visualized live endothelial-leukocyte (LEU) interactions and BBB microvascular leakage. Twice daily clinical recovery was assessed by regaining of lost body weight and the Garcia Neurological Test (motor, sensory, reflex, balance assessments). Brain edema was determined by hemispheric wet-to-dry ratios. RESULTS: Propranolol after TBI reduced both in vivo LEU rolling and BBB permeability in a dose-dependent fashion compared with no treatment (p < 0.001). Propranolol reduced cerebral edema (p < 0.001) and hastened recovery of lost body weight at 48 hours (p < 0.01). Compared with no treatment (14.9 ± 0.2), 24-hour Garcia Neurologic Test scores were improved with 2 (15.8 ± 0.2, p = 0.02) and 4 (16.1 ± 0.1, p = 0.001) but not with 1 mg/kg propranolol. CONCLUSION: Propranolol administration reduces post-TBI LEU mobilization and microvascular permeability in the murine penumbral neurovasculature and leads to reduced cerebral edema. This is associated with hastened recovery of post-TBI weight loss and neurologic function with bb treatment. Dose-dependent effects frame a mechanistic relationship between bb and improved human outcomes after TBI.

Definition of periprosthetic joint infection: is there a consensus?

BACKGROUND: The diagnosis of periprosthetic joint infection (PJI) continues to pose a challenge. While many diagnostic criteria have been proposed, a gold standard for diagnosis is lacking. Use of multiple diagnostic criteria within the joint arthroplasty community raises concerns in patient treatment and comparison of research pertaining to PJI. QUESTIONS/PURPOSES: We (1) determined the variation in existing diagnostic criteria, (2) compared the existing criteria to a proposed new set of criteria that incorporates aspirate cell count analysis, and (3) investigated the variations between the existing criteria and the proposed criteria. PATIENTS AND METHODS: We retrospectively identified 182 patients undergoing 192 revision knee arthroplasties who had a preoperative joint aspiration analysis at our institution between April 2002 and November 2009. We excluded 20 cases due to insufficient laboratory parameters, leaving 172 cases for analysis. We applied six previously published sets of diagnostic criteria for PJI to determine the variation in its incidence using each set of criteria. We then compared these diagnostic criteria to our proposed new criteria and investigated cases where disagreement occurred. RESULTS: We identified 41 cases (24%) in which at least one established criteria set classified the case as infected while at least one other criteria set classified the case as uninfected. With our proposed criteria, the infected/uninfected ratio was 92/80. The proposed criteria had a large variance in sensitivity (54%-100%), specificity (39%-100%), and accuracy (53%-100%) when using each of the established criteria sets as the reference standard. CONCLUSIONS: The discrepancy between definitions of infection complicates interpretation of the literature and the treatment of failed TKAs owing to PJI. Based on our findings, we suggest establishing a common set of diagnostic criteria utilizing aspirate analysis to improve the treatment of PJI and facilitate interpretation of the literature. LEVEL OF EVIDENCE: Level III, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.