Decreased Glycocalyx Shedding on Presentation in Hemorrhaging Geriatric Trauma Patients.

INTRODUCTION: Plasma levels of syndecan-1 (Sdc-1), a biomarker of endothelial glycocalyx (EG) damage, correlate with worse outcomes in trauma patients. However, EG injury is not well characterized in injured older adults (OA). The aims of this study were to characterize Sdc-1 shedding in OA trauma patients relative to younger adults (YA) and determine associations with putative regulators of EG sheddases. METHODS: We performed a secondary analysis of data from the Pragmatic, Randomized Optimal Platelet, and Plasma Ratios (PROPPR) trial, stratifying bluntly injured subjects into OA and YA groups based on upper age quartile (57 y). Plasma Sdc-1 levels were compared in OA and YA at hospital arrival through postinjury day 3, and the independent association between age and Sdc-1 level at arrival was determined after adjusting for differences in gender, shock index (SI), and pre-existing comorbidities. In a follow-up analysis, case-control matching was used to create populations of OA and YA with equivalent SI and injury severity score. Levels of Sdc-1 were compared between these matched groups, and the relationships with candidate regulators of EG shedding were assessed. RESULTS: Of 680 subjects in the Pragmatic, Randomized Optimal Platelet, and Plasma Ratios trial, 350 (51%) had blunt injuries, and 92 (26.3%) of these were OA. Plasma Sdc-1 levels at arrival, 2 h, and 6 h were significantly lower in OA compared to YA (all P < 0.05). After adjusting for sex, pre-existing morbidities and SI, age was associated with decreased Sdc-1 levels at arrival. In the matched analyses, Sdc-1, high-mobility group box 1 and tissue inhibitor of metalloproteinase-2 levels were lower in OA compared to YA. Both high-mobility group box-1 and tissue inhibitor of metalloproteinase-2 significantly correlated with arrival Sdc-1 and were inversely associated with age. CONCLUSIONS: This study indicates that increased age is independently associated with decreased Sdc-1 levels among patients with blunt injuries. Suppressed plasma levels of sheddases in relation to diminished Sdc-1 shedding suggest that mechanisms regulating EG cleavage may be impaired in injured older adults. These findings provide novel insight into the age-dependent impact of injury on the vascular endothelium, which could have important implications for the clinical management of older adults following trauma.

Medical Students' Perceptions of Orthopedics as a Career for Women.

OBJECTIVES: To determine potential factors influencing female medical students' interest and subsequent application to orthopedics, and to evaluate female and male medical students' perceptions of women in the field of orthopedics. METHODS: An institutional review board-approved survey was distributed in March 2020 and subsequently in April 2022 to medical students in the classes of 2023 and 2024 at the University of Alabama at Birmingham Heersink School of Medicine. Study data were collected and managed using REDCap electronic data capture. An e-mail link to the REDCap survey was sent to students across the southeast region of the United States, followed by three reminder e-mails. All 25 allopathic medical schools in the southeastern United States with an Orthopedics Interest Group listed on their institution's Web site were invited to participate in the study. Nine Orthopedics Interest Group leaders interested in participating were asked to provide the researchers with a list of fourth-year medical students who attended an event hosted by that group (215). A total of 39 respondents who completed the survey were included in this study. RESULTS: Overall, the majority of students (n = 35, 90%) believed that women faced more barriers to a career in orthopedics than did men. The most significant barriers to women entering the field of orthopedics were the perceived expectations of an orthopedic surgeon (n = 34, 87%), difficulty balancing career and family (n = 28, 72%), and demanding schedule (n = 13, 33%). CONCLUSIONS: This study demonstrates that both male and female medical students believe there are significant additional barriers to success for women in the field. Study participants report that expectations set by physicians, other healthcare professionals, and patients contribute to creating greater barriers that deter medical students interested in orthopedics from ultimately applying to the specialty.

CNS and Thorax Injury and Associated Risks Factors in Equestrian Sports.

CONTEXT: Equestrian sports continue to gain popularity in the United States and are associated with a high injury rate, especially involving the central nervous system and thorax. Due to this high rate of injury and the potential for long-term consequences associated with participation, an understanding of the unique risks of this sport is needed. OBJECTIVE: To describe severe injury in equestrian sports and review the role that protective gear plays in injury mitigation. DATA SOURCES: The PubMed Database was searched using the search terms "equestrian" and "horse" combined with "spinal cord injury," "head injury," "traumatic brain injury," "experience levels," and "demographics." STUDY SELECTION: A total of 53 papers were selected based on their relevance of epidemiology, risk factors, and management of injuries sustained during equestrian activities. Case studies, randomized controlled trials, prospective studies, and retrospective studies were all included for further review. STUDY DESIGN: Systematic review. LEVEL OF EVIDENCE: Level 4. DATA EXTRACTION: None. RESULTS: Injuries to the thorax, including fractures, pneumothoraces, internal organ contusions, and crush injuries, have been cited in multiple national and international trauma registries as the most prevalent injury location in equestrians; however, head and neck injuries, high cervical spine fractures, and closed head injuries are reported to be associated with the highest rates of mortality. Helmets provide protection against skull fracture and traumatic brain injury. Vests were not associated with diminished rates of spinal cord injuries; however, they may provide protection to the thorax. Riding experience also plays a role in reducing the prevalence of injury. CONCLUSION: Equestrian-related activities are associated with a high risk of injury despite protective measures. Protective gear can mitigate some injury risk but does not protect against spinal injury. Continued investigation into improving protective equipment, rider education, and preventative strategies to mitigate this risk is needed.

Long-term Outcomes of Multiligament Knee Injuries in American Football Players.

BACKGROUND: Long-term outcomes for isolated anterior cruciate ligament (ACL) reconstructions in competitive American football athletes are well reported in the literature, but little data currently exist regarding multiligament knee injury (MLKI) reconstruction outcomes. PURPOSE: To examine patient-reported and return-to-sport outcomes of competitive American football athletes who underwent primary, single-staged, multiligament knee reconstruction. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: We identified patients from our institution's prospectively collected data repository between 2001 and 2020 who underwent single-staged surgical reconstruction of an MLKI sustained during competitive participation in American football. We assessed patient-reported outcomes at a minimum of 2 years after surgery using the International Knee Documentation Committee (IKDC) Subjective Knee Form and questions regarding surgical satisfaction and return to sport. Successful return to sport was defined as a return to preinjury level of competition. We summarized all outcome data and compared outcomes between 2-ligament and >2-ligament groups and between ACL-only MLKI injury and bicruciate MLKI injury groups using independent t test for IKDC scores and chi-square test for return to sport. Additionally, we evaluated predictors of postoperative IKDC scores using linear regression and predictors of return to sport using logistic regression. RESULTS: Outcome data were successfully collected for 53 of 73 total eligible patients (73%; mean follow-up time, 7.7 ± 4.0 years; all male; mean age at surgery, 18.1 ± 2.7 years). The mean postoperative IKDC score was 84 ± 16. The most common level of preinjury competition was high school (n = 36; 68%), followed by college (n = 10; 19%). Seven patients did not return to sport competition at any level due to limitations from their knee surgery, and 82% of patients that attempted to return to preinjury level of sport were able to do so. A total of 50 patients (94%) were satisfied or very satisfied with their surgical outcome. The 2-ligament (n = 39) and >2-ligament (n = 14) groups did not significantly differ in IKDC scores (P = .96) or proportions with successful return to sport (P = .77). Similarly, the ACL-MLKI injury (n = 39) and bicruciate MLKI injury (n = 14) groups did not significantly differ in IKDC scores (P = .89) or proportions with successful return to sport (P = .77). Age and body mass index were not significantly associated with IKDC scores or successful return to sport at follow-up (all P > .05). CONCLUSION: This study may represent the largest cohort of competitive American football athletes evaluated for longitudinal outcomes after multiligament knee reconstruction. Despite the severity of these injuries, we found good knee-related function and that the large majority of athletes who attempted to return to sport were successful. The majority of athletes (94%) were satisfied with their operative treatment.

Outcomes of Surgical Treatment for Multiligament Knee Injuries in a Cohort Including Competitive Athletes With Long-Term Follow-Up.

Background: There is a paucity of outcomes data on surgical reconstruction for multiligament knee injury (MLKI) in the orthopaedic literature. Purpose: To examine functional and return-to-sports (RTS) outcomes and revision rates after single-stage reconstruction for MLKIs in a cohort containing a large proportion of competitive athletes over a 20-year period. Study Design: Case series; Level of evidence, 4. Methods: We identified all patients at our institution who underwent surgical reconstruction for an anterior cruciate ligament (ACL) or bicruciate (ACL-posterior cruciate ligament) MLKI between 2001 and 2020 and had ≥2 years of postoperative outcome data. Patient-reported outcomes were evaluated using the International Knee Documentation Committee (IKDC) form, a surgical satisfaction survey, and questions about subsequent knee surgery and RTS administered via telephone. Summary statistics for all outcomes data were calculated, and predictors of IKDC scores at follow-up were examined using univariable linear regression. Results: Out of 151 patients eligible for this study, outcomes data were collected in 119 patients (79%). The mean follow-up time was 8.3 ± 4.4 years, and the mean IKDC score at follow-up was 79 ± 17. A total of 83 competitive athletes were included; 62 of these athletes attempted to return to preinjury sport. Among the 62 who attempted RTS, 50 (81%) were successful, and 12 were unable to return due to limitations from their surgery. At follow-up, 112 of the overall cohort of 119 patients (94%) were either satisfied or very satisfied with their surgical outcome, and 91% stated the surgery met or exceeded their expectations. In addition, 24% had subsequent ipsilateral knee operations after their index multiligament knee reconstruction. Older age at surgery and female sex were associated with worse IKDC scores at follow-up. Conclusion: Despite the severity of the injuries in our cohort, we found high levels of patient-reported function and a high rate of successful RTS in the competitive athletes. Older age and female sex were associated with worse patient-reported knee function at follow-up.

Beyond the IFA: Revisiting the ELISA as a More Sensitive, Objective, and Quantitative Evaluation of Spotted Fever Group Rickettsia Exposure.

Based on limited serological studies, at least 10% of the US population has been exposed to spotted fever group Rickettsia (SFGR) species. The immunofluorescence antibody assay (IFA) has been the gold standard for the serodiagnosis of rickettsial infections such as spotted fever rickettsiosis (SFR). However, the IFA is semi-quantitative and subjective, requiring a high level of expertise to interpret it correctly. Here, we developed an enzyme-linked immunosorbent assay (ELISA) for the serodiagnosis of Rickettsia parkeri infection in the guinea pig. Our ELISA is an objective, quantitative, and high-throughput assay that shows greater sensitivity and resolution in observed titers than the IFA. We methodically optimized relevant parameters in sequence for optimal signal-to-noise ratio and low coefficient of variation% values. We used a guinea pig model as it is a part of our overall research efforts to understand the immunological and clinical response to SFGR species after tick transmission. Guinea pigs are a useful model to study SFR and show clinical signs of SFR, such as fever and eschars. We anticipate that this assay will be easily adapted to other hosts, including humans and other SFGR species.

An optimized five-color/seven-parameter flow cytometry panel for immunophenotyping guinea pig peripheral blood lymphocytes.

Guinea pigs are an ideal animal model for the study of several infectious diseases, including tuberculosis, legionellosis, brucellosis, and spotted fever rickettsiosis. In comparison to the murine model, clinical signs in guinea pigs are more representative of disease in humans, the guinea pig immune system is more similar to that of the human, and their large size offers logistic advantages for sample collection while following disease progression. Unfortunately, the advantage of using guinea pigs in biomedical research, particularly in understanding the immune response to infectious agents, is limited in large part by the paucity of available reagents and lack of genetically manipulated strains. Here, we expand the utility of guinea pigs in biomedical research by establishing an optimized five-color/seven-parameter polychromatic flow cytometric assay for immunophenotyping lymphocytes. This assay fills a need for immunophenotyping peripheral blood lymphocytes and is an improvement over current published flow cytometry assays for guinea pigs. We anticipate that our approach will be an important starting point for developing new assays to evaluate the cellular immune response to infectious diseases in the guinea pig model. Importantly, we are currently using this assay for evaluating immunity to spotted fever rickettsiosis in a guinea pig-tick-Rickettsia system, where CD8+ T cells are a critical contributor to the immune response. Developing resources to utilize the guinea pig more effectively will enhance our ability to understand infectious diseases where the guinea pig would otherwise be the ideal model.