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This study aimed to identify differences in patient characteristics, perioperative management methods, and outcomes for total hip arthroplasty (THA) for femoral neck fracture (FNF) when performed by orthopaedic surgeons who have arthroplasty versus orthopaedic trauma training. This study was a multicenter retrospective review of 636 patients who underwent THA for FNF between 2010 and 2019. There were 373 patients who underwent THA by an arthroplasty surgeon, and 263 who underwent THA by an orthopaedic trauma surgeon. Comorbidities, management methods, and outcomes were compared between patients operated on by orthopaedic surgeons who had arthroplasty versus trauma training. Arthroplasty-trained surgeons had shorter operative times (102 versus 128 minutes, P <.0001) and utilized tranexamic acid more frequently than trauma-trained surgeons (48.8 versus 18.6%, P <.0001). Orthopaedic trauma surgeons more frequently utilized an anterior approach. Patients of arthroplasty-trained surgeons had lower rates of complications including pulmonary embolism (1.6 versus 6.5%, P =.0019) and myocardial infarction (1.6 versus 11.0%, P <.0001). Similarly, patients of arthroplasty-trained surgeons were discharged faster (5.3 versus 7.9 days, P <.0001) with greater ambulation capacity (92.2 versus 57.2 feet, P <.0001). Dislocation, periprosthetic joint infection, and revision were similar between both groups. When adjusted for covariates, there was no difference in 90-day, 1-year, or 2-year mortality. A THA performed for FNF by arthroplasty surgeons was associated with lower in-hospital morbidities and improved functional statuses at discharge. However, mortalities and complications after discharge were similar between both specialties when adjusted for confounding variables. Optimization of protocols may further improve outcomes for THA for FNF. [ABSTRACT FROM AUTHOR]

Anaerobic bacteria are responsible for half of all pulmonary infections. One such pathogen is Streptococcus pneumoniae (Spn), a leading cause of community-acquired pneumonia, bacteremia/sepsis, and meningitis. Using a panel of isogenic mutants deficient in lactate, acetyl-CoA, and ethanol fermentation, as well as pharmacological inhibition, we observed that NAD(H) redox balance during fermentation was vital for Spn energy generation, capsule production, and in vivo fitness. Redox balance disruption in fermentation pathway-specific fashion substantially enhanced susceptibility to killing in antimicrobial class-specific manner. Blocking of alcohol dehydrogenase activity with 4-methylpyrazole (fomepizole), an FDA-approved drug used as an antidote for toxic alcohol ingestion, enhanced susceptibility of multidrug-resistant Spn to erythromycin and reduced bacterial burden in the lungs of mice with pneumonia and prevented the development of invasive disease. Our results indicate fermentation enzymes are de novo targets for antibiotic development and a novel strategy to combat multidrug-resistant pathogens. Antibiotic resistance is a increasingly important problem for Streptococcus pneumoniae infections. This study shows that blocking fermentation and disrupting redox balance increases the sensitivity of this bacterium to antibiotics, including validation in vivo using a pneumonia model with antibiotic resistant pneumococci. [ABSTRACT FROM AUTHOR]

Background: A consensus definition recently was formulated for fracture-related infection, which centered on confirmatory criteria including conventional cultures that take time to finalize and have a 10% to 20% false-negative rate. During this time, patients are often on broad-spectrum antibiotics and may remain hospitalized until cultures are finalized to adjust antibiotic regimens.Questions/purposes: (1) What is the diagnostic accuracy of isothermal microcalorimetry, and how does its accuracy compare with that of conventional cultures? (2) Does isothermal microcalorimetry decrease time to detection (or diagnosis) of fracture-related infection compared with conventional cultures? (3) Does isothermal microcalorimetry have a diagnostic accuracy or time advantage over conventional cultures in patients on chronic suppressive antibiotics?Methods: Between July 2020 and August 2021, we treated 310 patients with concerns for infection after prior fracture repair surgery. Of those, we considered all patients older than 18 years of age with fixation hardware in place at the time of presentation as potentially eligible. All included patients returned to the operating room with cultures obtained and assessed by both isothermal microcalorimetry and conventional cultures, and all were diagnosed using the consensus criteria for fracture-related infection. Based on that, 81% (250 of 310) of patients were eligible; a further 51% (157 of 310) were excluded because of the following reasons: the capacity of the isothermal microcalorimetry instrument limited the throughput on that day (34% [106 of 310]), they had only swab cultures obtained in surgery (15% [46 of 310]), or they had less than 3 months follow-up after surgery for infectious concerns (2% [5 of 310]), leaving 30% (93 of 310) of the originally identified patients for analysis. We obtained two to five cultures from each patient during surgery, which were sent to our clinical microbiology laboratory for standard processing (conventional cultures). This included homogenization of each tissue sample individually and culturing for aerobic, anaerobic, acid-fast bacilli, and fungal culturing. The remaining homogenate from each sample was then taken to our orthopaedic research laboratory, resuspended in growth media, and analyzed by isothermal microcalorimetry for a minimum of 24 hours. Aerobic and anaerobic cultures were maintained for 5 days and 14 days, respectively. Overall, there were 93 patients (59 males), with a mean age of 43 ± 14 years and a mean BMI of 28 ± 8 kg/m 2 , and 305 tissue samples (mean 3 ± 1 samples per patient) were obtained and assessed by conventional culturing and isothermal microcalorimetry. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of isothermal microcalorimetry to diagnose fracture-related infection were compared with conventional cultures using a McNemar test based on the consensus definition of fracture-related infection. This consensus criteria is comprised of two levels of certainty for the diagnostic variables. The first is confirmatory criteria, where infection is considered definitely present and includes the presence of fistula/sinus tract/wound breakdown, purulent drainage or the presence of pus, presence of microorganisms in deep tissue specimens on histopathologic examination, presence of more than five neutrophils/high-powered field by histopathologic examination (only for chronic/late onset cases), and identification of phenotypically indistinguishable pathogens by conventional culture from at least two separate deep tissue/implant specimens. The second is suggestive criteria in which further investigation is required to achieve confirmatory status. Fracture-related infection was diagnosed for this study to minimize subjectivity based on the presence of at least one of the confirmatory criteria as documented by the managing surgeon. When suggestive criteria were present without confirmatory criteria, patients were considered negative for fracture-related infection and followed further in clinic after surgical exploration (n = 25 patients). All 25 patients deemed not to have fracture-related infection were considered infection-free at latest follow-up (range 3 to 12 months). The time to detection or diagnosis was recorded and compared via the Mann-Whitney U test.Results: Using the consensus criteria for fracture-related infection, there were no differences with the numbers available between isothermal microcalorimetry and conventional cultures in terms of sensitivity (87% [95% confidence interval 77% to 94%] versus 81% [95% CI 69% to 89%]), specificity (100% [95% CI 87% to 100%] versus 96% [95% CI 79% to 99%]), PPV (100% [95% CI 90% to 100%] versus 98% [95% CI 89% to 99%]), NPV (74% [95% CI 60% to 84%] versus 65% [95% CI 52% to 75%]), or accuracy (90% [95% CI 83% to 96%] versus 85% [95% CI 76% to 91%]; p = 0.13). The concordance by sample between conventional cultures and isothermal microcalorimetry was 85%. Isothermal microcalorimetry had a shorter median (range) time to detection or diagnosis compared with conventional cultures (2 hours [0.5 to 66] versus 51 hours [18 to 147], difference of medians 49 hours; p < 0.001). Additionally, 32 patients used antibiotics for a median (range) duration of 28 days (7 to 1095) before presentation. In these unique patients, there were no differences with the numbers available between isothermal microcalorimetry and conventional cultures in terms of sensitivity (89% [95% CI 71% to 98%] versus 74% [95% CI 53% to 88%]), specificity (100% [95% CI 48% to 100%] versus 83% [95% CI 36% to 99%]), PPV (100% [95% CI 85% to 100%] versus 95% [95% CI 77% to 99%]), NPV (63% [95% CI 37% to 83%] versus 42% [95% CI 26% to 60%]), or accuracy (91% [95% CI 75% to 98%] versus 78% [95% CI 57% to 89%]; p = 0.17). Isothermal microcalorimetry again had a shorter median (range) time to detection or diagnosis compared with conventional cultures (1.5 hours [0.5 to 48] versus 51.5 hours [18 to 125], difference of medians 50 hours; p < 0.001).Conclusion: Given that isothermal microcalorimetry considerably decreases the time to the diagnosis of a fracture-related infection without compromising the accuracy of the diagnosis, managing teams may eventually use isothermal microcalorimetry-pending developmental improvements and regulatory approval-to rapidly detect infection and begin antibiotic management while awaiting speciation and susceptibility testing to modify the antibiotic regimen. Given the unique thermograms generated, further studies are already underway focusing on speciation based on heat curves alone. Additionally, increased study sizes are necessary for both overall fracture-related infection diagnostic accuracy and test performance on patients using long-term antibiotics given the promising results with regard to time to detection for this groups as well.Level Of Evidence: Level II, diagnostic study. [ABSTRACT FROM AUTHOR]

Introduction: The objectives of this study are to report the rates of positive intraoperative cultures obtained during conversion total hip arthroplasty (THA) according to index surgery, and to describe the natural history of treatment for a consecutive series of patients with unexpected positive intraoperative cultures during conversion THA. Methods: We reviewed all patients at 2 institutions undergoing conversion THA from prior open reduction and internal fixation (ORIF) of acetabular and hip fractures or hemiarthroplasty for displaced femoral neck fractures from 2011 to 2018. Intraoperative cultures were taken in 105 patients. Positive intraoperative cultures during conversion were recorded and managed with an infectious diseases consult. The outcomes including PJI at 90 days and 1 year follow-up were documented. Results: Overall, 19 of 105 patients (18%) undergoing conversion THA had positive intraoperative cultures, with the highest rates in the hemiarthroplasty 7/16 (44%) and acetabular ORIF 9/48 (19%) groups. All 19 patients were initially treated conservatively: 8 received IV antibiotics, 10 received no additional therapy, and 1 received oral antibiotics. 4/9 acetabular fracture conversions developed PJI at 1 year, with 3 requiring multiple irrigation and debridement/polyethylene exchanges to control the infection while the 4th patient required 2-stage exchange. There were no 1-year PJI from any of the other index procedures after conversion. All 7 hemiarthroplasty patients with positive cultures were treated to resolution with 4–8 weeks IV antibiotics alone. Conclusions: Patients undergoing conversion THA from prior hip or acetabular fracture have a high rate of positive intraoperative cultures. As such, all patients undergoing conversion THA from prior hip or acetabular fracture fixation should undergo thorough diagnostic workup prior to surgery, and have intraoperative cultures obtained during surgery if infection remains suspicious. Further work should be performed to develop MSIS criteria for preoperative management of patients undergoing conversion THA. [ABSTRACT FROM AUTHOR]

Background: Surgical site infection (SSI) occurs in 5% to 7% of patients undergoing operative fixation of acetabular fractures, with reported risk factors including longer operative duration, increased blood loss, pelvic artery embolization, and concurrent abdominal organ injury, among others. Psoas muscle density is a measure of muscle quality and, as a metric for sarcopenia and/or nutrition status, has been associated with poor outcomes such as mortality across multiple surgical specialties. To date, psoas muscle density has not been explored for its associations with SSI in acetabular fracture patients.Questions/purposes (1) Is decreased psoas muscle density, as measured by Hounsfield units, associated with an increased SSI risk after acetabular fracture fixation? (2) What patient, operative, and hospital variables are associated with an increased SSI risk after acetabular fracture fixation?Methods: Between 2012 to 2017, surgeons performed 684 acetabular ORIF procedures at one level I trauma center. Of those, 8% (56 of 684) did not meet inclusion criteria, leaving 92% (n = 628) for analysis in this study. The median (range) follow-up duration was 12 months (0.5-77). Patient demographics, comorbidities, operative and in-hospital variables, and psoas muscle density measured using preoperative pelvic CT images-acquired for all operative acetabular fracture patients-were analyzed. SSI was defined by positive culture results obtained during irrigation and débridement. Overall, 7% (42 of 628) of patients had an SSI. A multivariable regression analysis was performed to identify independent risk factors. Sensitivity analysis was performed with minimum follow-up set at 3 months and 6 months.Results: There was no difference in the mean psoas muscle density between patients with SSI (50.9 ± 10.2 Hounsfield units [HUs]) and those who did not have an SSI within 1 year of open reduction and internal fixation (51.4 ± 8.1 HUs) (mean difference: 0.5 [95% confidence interval -2.34 to 3.32]; p = 0.69). Four variables were independently associated with an increased risk of SSI: increased operative time (1.04 [95% CI 1.00 to 1.07]; p = 0.03), estimated blood loss (1.08 [95% CI 1.02 to 1.14]; p = 0.01), female sex (2.34 [95% CI 1.19 to 4.60]; p = 0.01), and intravenous drug use (3.95 [95% CI 1.51 to 10.33]; p = 0.01). Sensitivity analysis showed no change in results using either 3-month or 6-month minimum follow-up.Conclusions: Risk factors for SSI after acetabular fixation include female sex, intravenous drug use, prolonged operative times, and increased intraoperative blood loss. Although the density of the psoas muscle may be a surrogate for nutritional markers, it was not associated with SSI in our patients with acetabular fractures. Thus, it is not useful for risk assessment of SSI in the general population with acetabular fracture; however, future studies with larger sample sizes of patients older than 60 years may re-investigate this marker for SSI risk. Contrary to the results of previous studies, pelvic artery embolization, intraoperative blood transfusion, and intensive care unit stay did not increase the risk of SSI; however, we may have been underpowered to detect differences in these secondary endpoints. Future large, multisite studies may be needed to address these conflicting results more definitively.Level Of Evidence: Level III, therapeutic study. [ABSTRACT FROM AUTHOR]

Orthopedic surgeons frequently encounter medical malpractice claims. The purpose of this study was to assess trends and risk factors in lawsuits brought against orthopedic surgeons using a national legal database. A legal research service was used to search publicly available settlement and verdict reports between 1988 and 2013 by terms "orthopaedic or orthopedic" and "malpractice." Temporal trends were evaluated, and logistic regression was used to identify independent risk factors for case outcomes. A total of 1562 publicly reported malpractice cases brought against orthopedic surgeons, proceeding to trial during a 26-year period, were analyzed. The plaintiffs won 462 (30%) cases, with a mean award of $1.4 million. The frequency of litigation and pay-outs for plaintiffs increased 215% and 280%, respectively, between the first and last 5-year periods. The mean payout for plaintiff-favorable verdicts was highest in pediatrics ($2.6 million), followed by spine ($1.7 million) and oncology ($1.6 million). Fracture fixation (363 cases), arthroplasty (290 cases), and spine (231 cases) were the most commonly litigated procedures, while plaintiffs were most successful for fasciotomy (48%), infection-treating procedures (43%), and carpal tunnel release (37%). When analyzing data by state and region, adjusted for population, northeastern states had a higher frequency of lawsuits. Malpractice liability has increased during the past 3 decades while orthopedic surgeons continue to win most of the cases making it to court. As patients search for medical care via publicly available information, it is important for orthopedic surgeons to understand what aspects of their own practice carry different risks of litigation. [Orthopedics. 2019; 42(2):e260-e267.]. [ABSTRACT FROM AUTHOR]

Introduction: Hip fractures and metabolic syndrome (MetS) are becoming major global healthcare burdens as populations age. This study sought to determine the impact of MetS in hip fracture patients on perioperative outcomes following operative fixation or arthroplasty.Methods: Data from the 2004-2014 Nationwide Inpatient Sample was used to select 3,348,207 discharges with hip fracture. MetS patients were identified by having at least 3 of 4 component comorbidities: hypertension, dyslipidemia, obesity, and diabetes. Logistic regression was used to estimate odds ratios for the association between MetS and perioperative outcomes adjusted for age, gender, race, payer status, and comorbidities.Results: Overall, 32% of hip fracture patients were treated with open reduction internal fixation (ORIF), 28% hemiarthroplasty (HA), 18% closed reduction with internal fixation (CRPP), and 3% primary total hip arthroplasty (THA). The remaining 19% of cases were either treated via unspecified procedure of hip repair (9%), managed non-operatively (2%), underwent multiple procedures during the hospital stay (6%), or the surgical procedure data was missing (2%) and were excluded from procedural analyses. The prevalence of MetS was 7.9% and increased among minorities, patients treated at urban hospitals, with comorbidities (heart failure, kidney disease, peripheral vascular disease), and with Medicare coverage. MetS was associated with increased odds of any adverse event (p < 0.0001), specifically: acute renal failure, myocardial infarction, acute posthemorrhagic anemia. MetS was also associated with increased LOS (p < 0.0001) and increased total charges (p < 0.0001). However, MetS was associated with reduced odds of postoperative pneumonia, deep vein thrombosis and pulmonary embolism, surgical site infection, septicemia, and in-hospital mortality (p < 0.0001). The above associations were maintained for MetS patients stratified according to their treatment groups: HA, CRPP, and ORIF.Conclusions: MetS is associated with increased odds of complications in hip fracture patients but decreased odds of in-hospital mortality. This may be related to patients' nutritional status and catabolic states in the perioperative period. [ABSTRACT FROM AUTHOR]

Background Our objective is to show the effect that standardization of surgical trays has on the number of instruments sterilized and on cost. Methods We reviewed our most commonly used surgical trays with the 3 general thoracic surgeons in our division and agreed upon the least number of surgical instruments needed for mediastinoscopy, video-assisted thoracoscopic surgery, robotic thoracic surgery, and thoracotomy. Results We removed 59 of 79 instruments (75%) from the mediastinoscopy tray, 45 of 73 (62%) from the video-assisted thoracoscopic surgery tray, 51 of 84 (61%) from the robotic tray, and 50 of 113 (44%) from the thoracotomy tray. From January 2016 to December 2016, the estimated savings by procedure were video-assisted thoracoscopic surgery (n = 398) $21,890, robotic tray (n = 231) $19,400, thoracotomy (n = 163) $15,648, and mediastinoscopy (n = 162) $12,474. Estimated total savings were $69,412. The weight of the trays was reduced 70%, and the nonsteamed sterilization rate (opened trays that needed to be reprocessed) decreased from 2% to 0%. None of the surgeons requested any of the removed instruments. Conclusions Standardization of thoracic surgical trays is possible despite having multiple thoracic surgeons. This process of lean (the removal of nonvalue steps or equipment) reduces the number of instruments cleaned and carried and reduces cost. It may also reduce the incidence of “wet loads” that require the resterilization of instruments. [ABSTRACT FROM AUTHOR]

Chlamydia trachomatis, an obligate intracellular pathogen, grows inside of a vacuole, termed the inclusion. Within the inclusion, the organisms differentiate from the infectious elementary body (EB) into the reticulate body (RB). The RB communicates with the host cell through the inclusion membrane to obtain the nutrients necessary to divide, thus expanding the chlamydial population. At late time points within the developmental cycle, the RBs respond to unknown molecular signals to redifferentiate into infectious EBs to perpetuate the infection cycle. One strategy for Chlamydia to obtain necessary nutrients and metabolites from the host is to intercept host vesicular trafficking pathways. In this study we demonstrate that a trans-Golgi soluble N-ethylmaleimide-sensitive factor attachment protein (SNARE), syntaxin 10, and/or syntaxin 10-associated Golgi elements colocalize with the chlamydial inclusion. We hypothesized that Chlamydia utilizes the molecular machinery of syntaxin 10 at the inclusion membrane to intercept specific vesicular trafficking pathways in order to create and maintain an optimal intra-inclusion environment. To test this hypothesis, we used siRNA knockdown of syntaxin 10 to examine the impact of the loss of syntaxin 10 on chlamydial growth and development. Our results demonstrate that loss of syntaxin 10 leads to defects in normal chlamydial maturation including: variable inclusion size with fewer chlamydial organisms per inclusion, fewer infectious progeny, and delayed or halted RB-EB differentiation. These defects in chlamydial development correlate with an overabundance of NBD-lipid retained by inclusions cultured in syntaxin 10 knockdown cells. Overall, loss of syntaxin 10 at the inclusion membrane negatively affects Chlamydia. Understanding host machinery involved in maintaining an optimal inclusion environment to support chlamydial growth and development is critical toward understanding the molecular signals involved in successful progression through the chlamydial developmental cycle. [ABSTRACT FROM AUTHOR]

Understanding how host proteins are targeted to pathogen-specified organelles, like the chlamydial inclusion, is fundamentally important to understanding the biogenesis of these unique subcellular compartments and how they maintain autonomy within the cell. Syntaxin 6, which localizes to the chlamydial inclusion, contains an YGRL signal sequence. The YGRL functions to return syntaxin 6 to the trans-Golgi from the plasma membrane, and deletion of the YGRL signal sequence from syntaxin 6 also prevents the protein from localizing to the chlamydial inclusion. YGRL is one of three YXXL (YGRL, YQRL, and YKGL) signal sequences which target proteins to the trans-Golgi.We designed various constructs of eukaryotic proteins to test the specificity and propensity of YXXL sequences to target the inclusion. The YGRL signal sequence redirects proteins (e.g., Tgn38, furin, syntaxin 4) that normally do not localize to the chlamydial inclusion. Further, the requirement of the YGRL signal sequence for syntaxin 6 localization to inclusions formed by different species of Chlamydia is conserved. These data indicate that there is an inherent property of the chlamydial inclusion, which allows it to recognize the YGRL signal sequence. To examine whether this "inherent property" was protein or lipid in nature, we asked if deletion of the YGRL signal sequence from syntaxin 6 altered the ability of the protein to interact with proteins or lipids. Deletion or alteration of the YGRL from syntaxin 6 does not appreciably impact syntaxin 6-protein interactions, but does decrease syntaxin 6-lipid interactions. Intriguingly, data also demonstrate that YKGL or YQRL can successfully substitute for YGRL in localization of syntaxin 6 to the chlamydial inclusion. Importantly and for the first time, we are establishing that a eukaryotic signal sequence targets the chlamydial inclusion. [ABSTRACT FROM AUTHOR]