Addition of the Sartorius Tendon Improves Biomechanics of a Four-Strand Hamstring Anterior Cruciate Ligament Autograft.

PURPOSE: The purpose of this study was to quantify and compare the biomechanical properties and change in graft size when adding the sartorius tendon as a fifth strand to a four-strand ST-G hamstring autograft. Additionally, the sartorius tendon was tested individually to quantify its independent biomechanical properties. METHODS: Four-strand and five-strand hamstring tendon grafts were harvested from matched cadaveric knees (mean age: 81.6 ± 9.8). These matched grafts were biomechanically tested using a MTS servohydraulic test system at a rate of testing representative of physiologic tears. The mean diameter, cross-sectional area, and ultimate load to failure were quantified and compared with a one-sided, paired Student's t-test. A P < .05 was considered statistically significant. RESULTS: The mean diameter of the five-strand graft was significantly larger than the four-strand graft (9.30 ± .84 mm vs 8.10 ± .42 mm; P = .002). The average ultimate load to failure of the five-strand graft was 65.3% higher than the four-strand graft (2984.05 ± 1085.11 N vs. 1805.03 ± 557.69 N; P = .009) and added 14.8% to the diameter of the four strand ST-G autograft. CONCLUSIONS: The addition of the sartorius tendon to a four-strand hamstring autograft significantly increased ultimate load to failure by 65%, graft cross-sectional area by 32%, and graft diameter by 15% compared to a traditional four-strand ST-G autograft. This information can be helpful to surgeons who wish to improve the strength of a four-strand ST-G autograft and for undersized grafts as an alternative to allograft supplementation. CLINICAL RELEVANCE: The addition of the sartorius to the four-strand ST-G hamstring autograft significantly increases the ultimate load to failure and overall graft diameter, which can be particularly helpful in undersized autografts as an alternative to allograft supplementation.

Midterm Safety of Carbon Dioxide Insufflation of the Knee During Arthroscopic Cartilage-Based Procedures.

BACKGROUND: When compared with fluid arthroscopy, carbon dioxide (CO2) insufflation offers an increased scope of view and a more natural-appearing joint cavity, and it eliminates floating debris that may obscure the surgeon's view. Despite the advantages of CO2 insufflation during knee arthroscopy and no reported cases of air emboli, the technique is not widely used because of concerns of hematogenous gas leakage and a lack of case series demonstrating safety. PURPOSE/HYPOTHESIS: To investigate the safety profile of CO2 insufflation during arthroscopic osteochondral allograft transplantation of the knee and report the midterm clinical outcomes using this technique. We hypothesized that patients undergoing CO2 insufflation of the knee joint would have minimal systemic complications, allowing arthroscopic cartilage work in a dry field. STUDY DESIGN: Case series; level of evidence, 4. METHODS: A retrospective chart review was performed of electronic medical records for patients who underwent arthroscopic osteochondral allograft transplantation of the knee with the use of CO2 insufflation. Included were patients aged 18 to 65 years who underwent knee arthroscopy with CO2 insufflation from January 1, 2015, to January 1, 2021, and who had a minimum follow-up of 24 months. All procedures were performed by a single, fellowship-trained and board-certified sports medicine surgeon. The patients' electronic medical records were reviewed in their entirety for relevant demographic and clinical outcomes. RESULTS: We evaluated 27 patients (14 women and 13 men) with a mean age of 38 and a mean follow-up of 39.2 months. CO2 insufflation was used in 100% of cases during the placement of the osteochondral allograft. None of the patients sustained any systemic complications, including signs or symptoms of gas embolism or persistent subcutaneous emphysema. CONCLUSION: The results of this case series suggest CO2 insufflation during knee arthroscopy can be performed safely with minimal systemic complications and provide an alternative environment for treating osteochondral defects requiring a dry field in the knee.

Multiethnic Uprisings in Urban America and their Implications for Progress.

In this article, the authors make a distinction between urban uprisings of earlier eras and the upheaval that has unfolded in the streets of America since the murders of Breonna Taylor and George Floyd by police officers in Louisville, Kentucky and Minneapolis, Minnesota. The authors wonder whether or not there is a correlation between these multiethnic/racial uprisings and non-Black residents' commitment to eradicating racism, especially when it comes to tackling problems that disproportionately impact African Americans.

Physicochemical characterization of Capstone depleted uranium aerosols II: particle size distributions as a function of time.

The Capstone Depleted Uranium (DU) Aerosol Study, which generated and characterized aerosols containing DU from perforation of armored vehicles with large-caliber DU penetrators, incorporated a sampling protocol to evaluate particle size distributions. Aerosol particle size distribution is an important parameter that influences aerosol transport and deposition processes as well as the dosimetry of the inhaled particles. These aerosols were collected on cascade impactor substrates using a pre-established time sequence following the firing event to analyze the uranium concentration and particle size of the aerosols as a function of time. The impactor substrates were analyzed using proportional counting, and the derived uranium content of each served as input to the evaluation of particle size distributions. Activity median aerodynamic diameters (AMADs) of the particle size distributions were evaluated using unimodal and bimodal models. The particle size data from the impactor measurements were quite variable. Most size distributions measured in the test based on activity had bimodal size distributions with a small particle size mode in the range of between 0.2 and 1.2 microm and a large size mode between 2 and 15 microm. In general, the evolution of particle size over time showed an overall decrease of average particle size from AMADs of 5 to 10 microm shortly after perforation to around 1 microm at the end of the 2-h sampling period. The AMADs generally decreased over time because of settling. Additionally, the median diameter of the larger size mode decreased with time. These results were used to estimate the dosimetry of inhaled DU particles.

Physicochemical characterization of Capstone depleted uranium aerosols I: uranium concentration in aerosols as a function of time and particle size.

During the Capstone Depleted Uranium (DU) Aerosol Study, aerosols containing DU were produced inside unventilated armored vehicles (i.e., Abrams tanks and Bradley Fighting Vehicles) by perforation with large-caliber DU penetrators. These aerosols were collected and characterized, and the data were subsequently used to assess human health risks to personnel exposed to DU aerosols. The DU content of each aerosol sample was first quantified by radioanalytical methods, and selected samples, primarily those from the cyclone separator grit chambers, were analyzed radiochemically. Deposition occurred inside the vehicles as particles settled on interior surfaces. Settling rates of uranium from the aerosols were evaluated using filter cassette samples that collected aerosol as total mass over eight sequential time intervals. A moving filter was used to collect aerosol samples over time, particularly within the first minute after a shot. The results demonstrate that the peak uranium concentration in the aerosol occurred in the first 10 s after perforation, and the concentration decreased in the Abrams tank shots to about 50% within 1 min and to less than 2% after 30 min. The initial and maximum uranium concentrations were lower in the Bradley vehicle than those observed in the Abrams tank, and the concentration levels decreased more slowly. Uranium mass concentrations in the aerosols as a function of particle size were evaluated using samples collected in a cyclone sampler, which collected aerosol continuously for 2 h after perforation. The percentages of uranium mass in the cyclone separator stages ranged from 38 to 72% for the Abrams tank with conventional armor. In most cases, it varied with particle size, typically with less uranium associated with the smaller particle sizes. Neither the Abrams tank with DU armor nor the Bradley vehicle results were specifically correlated with particle size and can best be represented by their average uranium mass concentrations of 65 and 24%, respectively.

Development of site profiles for dose reconstruction used in worker compensation claims.

For the purpose of dose reconstruction, personal dosimeter data and measured intakes through bioassay analysis (i.e., in-vivo and in-vitro measurements) should be used whenever possible and given precedence over area monitoring data, survey data, or source term data. However, this is not always possible. A worker's exposure record may be incomplete or missing, or, based on directives and guidelines at the time, a worker may not have been monitored during his or her time of employment. In an effort to recognize, analyze, and incorporate all possible considerations of potential exposures, the National Institute for Occupational Safety and Health Radiation Dose Reconstruction Program developed "site profiles" for all of the major U.S. Department of Energy sites and Atomic Weapons Employer sites. Site profiles are technical documents that (1) provide a brief, general overview of the site; (2) identify the facilities on site with a brief description of the processes and radionuclides used in these processes; (3) contain detailed information on the historical detection limits for film, thermoluminescent dosimeter, and bioassay measurements that are used by the dose reconstructor to interpret a worker's available monitoring records; and (4) provide important supporting information for the dose reconstructor to use if the monitoring data are inadequate or unavailable. When a complete set of monitoring data for an individual is unavailable, it is the parameters in the site profile that are of the most use to the dose reconstructor. These parameters include facility monitoring data (by radionuclide, mechanism of intake, year of exposure, location within a facility); occupational medical x rays and techniques used; environmental measurements (by area on site, radiation type, energy range); minimum detectable activities of the types and kinds of instruments used to detect the different radionuclides; specific source terms (quantities of material and their molecular form) within each facility or process; and specifics of the overall dosimetry programs as they evolved over time. An additional benefit of having a site profile for a site is that it promotes consistency among the numerous health physicists that are working on the project. Resources used in the development of site profiles include technical basis documents for external and internal dosimetry programs, facility descriptions, environmental reports, safety analysis reports, input from past and present site workers, and other reports that have been written to describe the workplace environments within the facilities.

Diagnosis of visceral leishmaniasis by enzyme-linked immunosorbent assay using urine samples.

A diagnostic method has been developed to detect anti-Leishmania donovani immunoglobulin G (IgG) in urine by enzyme-linked immunosorbent assay (ELISA). In measuring anti-L. donovani IgG, IgA, and IgM in urine, the method performed best in the detection of IgG. The sensitivity and specificity of the assay were determined with panels of urine samples from 62 visceral leishmaniasis (VL) patients, 59 healthy controls from areas of endemicity, 53 healthy controls from areas of nonendemicity, 59 malaria patients, 13 tuberculosis patients, 23 cutaneous leishmaniasis patients, and 7 patients with other diseases. Using L. donovani promastigote crude antigen, the test had 93.5% sensitivity (58 positives of 62 VL patient samples) and 89.3% specificity (191 negatives of 214 non-VL patient samples). The ELISA with acetone-treated L. donovani promastigote antigen raised the sensitivity and specificity to 95.0 and 95.3%, respectively. Western blot analysis revealed that most of the samples that cross-reacted with crude antigen in ELISA did not recognize any antigenic component of L. donovani crude antigen. We also checked 40 serum samples from the same group of VL patients for anti-L. donovani IgG and got 90.0% sensitivity with both crude and acetone-treated antigens. As collection of urine is much easier than collection of serum, the detection of anti-L. donovani IgG in urine with acetone-treated antigen will be useful in epidemiological studies. It could be an adjunct of laboratory diagnosis.

Anti-malarial drug resistance, malnutrition and socio-economic status.

To investigate the relationship between nutritional status and resistance to chloroquine treatment, we designed a nested case-control study prospective with respective to the outcome of Plasmodium falciparum-infected school children aged 5-14 years from Honiara, Solomon Islands. 38 chloroquine-resistant cases were compared with treatment-susceptible controls with respect to current nutritional status, behavioural characteristics, medical and demographic data. The overall prevalence of moderate malnutrition was 28%. The incidence rate of chloroquine resistance was 23%. Malnourished children were generally at higher risk for treatment failure than well-nourished ones (OR: 3.6; 95% CI: 1.6-8.4; P = 0.001). This effect was modified by socio-economic status. Stratified analysis by logistic regression resulted in an eightfold risk of resistance for malnourished children in the higher socio-economic category (OR: 8.1; 95% CI: 2.4-27.9; P = -.0001). In children from the lower socio-economic group, the effect of malnutrition was not significant (OR: 1.5; 95% CI: 0.4-5.6). Socio-economic differences may affect the immune status. The treatment response in children of lower socio-economic status, which are more exposed to malaria, may therefore be less affected by malnutrition.