Coated Cast Saw Blades Decrease Blade Temperature During Cast Removal.

BACKGROUND: Thermal injuries can occur during cast removal with an oscillating saw. The purpose of this study is to describe the effect of blade material, blade wear, and cast material on blade temperature. METHODS: Short arm plaster and fiberglass casts were cured overnight and bivalved with either new or worn stainless-steel or tungsten-disulfide coated blades. Blade use was defined as removing 1 short arm cast. Blades used to remove more than 20 casts were defined as worn. Ten trials were performed with each combination of blade material, blade wear, and cast material, except for the combination of fiberglass and a worn stainless-steel blade due to complete erosion of cutting teeth. Thirty casts were removed with stainless-steel blades, and 40 casts were removed with coated blades. Blade temperature was measured continuously at 5 Hz using a T-type thermocouple and microcontroller board. A Mann-Whitney U test was used to compare the mean maximum temperature between groups. RESULTS: For plaster casts, new and worn stainless-steel blades produced mean maximum temperatures of 51.4°C and 63.7°C ( P =0.003), respectively. New stainless-steel blades produced significantly higher mean maximum temperatures on fiberglass casts than plaster casts (95.9°C vs. 51.4°C, P <.001). For plaster casts, new and worn coated blades produced mean maximum temperatures of 56.9°C and 53.8°C ( P =0.347). For fiberglass casts, new and worn coated blades produced mean maximum temperatures of 76.6°C and 77.7°C ( P =0.653). As with new stainless-steel blades, new coated blades produced significantly higher mean maximum temperatures on fiberglass than plaster (76.6°C vs. 56.9°C, P <0.001). Mean maximum temperatures between new stainless-steel and coated blades during removal of plaster casts were 51.4°C and 56.9°C ( P =0.131), respectively. However, new coated blades demonstrated significantly lower mean maximum temperatures during fiberglass cast removal compared to new stainless-steel blades (76.6°C vs. 95.9°C, P =0.016). CONCLUSIONS: Coated blades outperformed stainless-steel in nearly all combinations. We recommend limited use of stainless-steel blades to minimize blade temperatures during cast removal. CLINICAL RELEVANCE: Appropriate selection of blade material and monitoring blade wear minimizes blade temperature during cast removal.

Injury rates in the National Football League during the 2020 COVID-19 season.

OBJECTIVES: The National Football League (NFL) altered the 2020 season due to the COVID-19 pandemic, which resulted in canceled preseason games and a dynamic regular season schedule to accommodate for canceled games. The purpose of this study was to evaluate if the disrupted training and preseason schedule lead to increased injury rates as seen in other professional sports. We hypothesized that the overall injury rate would be higher in the 2020 season compared to the 2018-2019 seasons and that this increase will affect all body regions equally. METHODS: Publicly released NFL weekly injury reports were queried to identify players listed as out or placed on the injured reserve for at least one game in the 2018-2020 seasons. Injuries were categorized into upper extremity, lower extremity, spine/core, head, illness, not injury related and undisclosed injuries. Incidents per 1000 athlete exposures were calculated for the prior two seasons (2018-2019) and for the 2020 season separately. Percentage of injuries occurring in each position was calculated separately for the pre-COVID-19 (2018 and 2019) and post-COVID-19 (2020) cohorts. Incidence rate ratios (IRR) and confidence intervals were used to compare injury rates in 2018-2019 versus 2020. The z-test for proportions was used to determine significant differences between injury incidences. RESULTS: The overall incidence rate per 1000 athlete exposures in 2020 was not significantly different compared to pre-COVID-19 seasons (21.6 versus 23.1, IRR 0.94, 95% CI: 0.9-1.0 p > 0.999). The proportion of injuries by position did not change before and after COVID-19 either (p > 0.999). Out listings due to illness were significantly increased during the 2020 season (0.8 versus 0.3, IRR 2.8, 95% CI: 1.4-5.2, p = 0.004). CONCLUSION: The incidence of NFL injuries did not significantly change in 2020. The distribution of injuries did not change with respect to position.

More Elevated Fastballs Associated With Placement on the Injured List due to Shoulder Injury.

Purpose: To evaluate whether impending shoulder injury was associated with changes in pitch location or velocity immediately preceding injury. Methods: Pitchers placed on the injured list (IL) due to a shoulder injury between 2015 and 2020 were identified in the Major League Baseball transactions database. Four-seam fastball velocity and frequency of pitch location for each pitch type was collected for each player in the season before placement on the IL and within 1 month of placement on the IL with a minimum of 55 pitches thrown of 1 type. Pitch locations were collected as identified by Baseball Savant's Game-Day Zones. Game-Day Zones were consolidated into high (above the strike zone midpoint) versus low, arm side (closer to the pitcher's arm side of the plate) versus opposite side, and within the strike zone versus out of zone. Repeated measures analysis of variance determined differences in four-seam velocity and the location distribution of 4-seam fastballs, change-ups, and breaking balls among each group. Results: In total, 267 pitchers were placed on the IL for a shoulder injury with the majority diagnosed with inflammation (89/267) followed by strain or sprain (69/267). Four-seam fastball locations significantly increased above the mid-point of the zone (45.9% vs 42.4%, P = .008) and out of the strike zone (48.5% vs 46.5%, P = .011) within a month before IL placement. There was no significant change in 4-seam fastball velocity immediately before IL placement. Conclusions: Pitchers threw more elevated 4-seam fastballs and out-of-zone 4-seam fastballs in the month before IL placement for shoulder injury. These findings suggest that a loss of 4-seam fastball command decreases with impending shoulder injury. Level of Evidence: IV, prognostic case series.

Secondary Injuries After Pediatric Anterior Cruciate Ligament Reconstruction: A Systematic Review With Quantitative Analysis.

BACKGROUND: In the skeletally mature anterior cruciate ligament (ACL) reconstruction population, patients aged <25 years are at significantly increased risk of graft failure and injury to the contralateral ACL. Skeletal immaturity often affects graft selection and reconstruction technique. PURPOSE: To examine the incidence of ipsilateral graft failure and contralateral ACL injury in the skeletally immature patient population. STUDY DESIGN: Systematic review and meta-analysis. METHODS: Using the PRISMA (Preferred Reporting Items for Systematic Meta-Analyses) guidelines, we reviewed all literature that involved ACL reconstruction performed on skeletally immature patients between May 1976 and May 2019. Patient demographics, surgical technique, and the prevalence of ipsilateral graft failure or subsequent contralateral ACL injury were recorded. Ipsilateral, contralateral, and secondary ACL injuries were then compared between sexes via chi-square tests. RESULTS: A total of 24 articles (1254 children; 1258 knees) met inclusion criteria for analysis. Ipsilateral graft failures occurred in 105 of 1258 patients (8.3%), and there were no statistically significant sex differences in the prevalence of graft failures (female, 9.7%; male patients, 7.1%; P = .14). The prevalence of contralateral ACL injury was significantly greater in female (29/129; 22.5%) than male (18/206; 8.7%; P = .0004) patients in the 9 studies that reported contralateral injury. Skeletally immature female patients were at significantly increased risk of contralateral ACL injury (odds ratio = 3.0; P = .0006) when compared with their male counterparts. CONCLUSION: In the literature to date, 1 in 3 female skeletally immature patients experienced an ipsilateral graft failure or contralateral ACL injury. Regardless of sex, the 24% prevalence of secondary injury after pediatric ACL reconstruction is almost identical to previously published secondary injury rates in skeletally mature patients <25 years old. As such, skeletal maturity alone does not seem to be a determinant of secondary injury; however, there is a clear need to improve postoperative rehabilitation, activity progression, and return-to-play testing to allow a safe return to sports that protects the long-term health of the reconstructed and contralateral limbs, especially for female patients.

A novel obstetric medical device designed for autotransfusion of blood in life threatening postpartum haemorrhage.

Postpartum haemorrhage (PPH) is an obstetric emergency caused by excessive blood loss after delivery, which is the leading cause of maternal mortality worldwide. PPH can lead to volume depletion, hypovolemic shock, anaemia and ultimately death. The prevalence of PPH is disproportionately higher in low resource settings where there is limited access to skilled medical care and safe blood supplies. Current management strategies target both prevention and treatment of PPH however no alternatives currently exist to address the lack of safe blood supplies which are considered essential in emergency obstetrical care. Autotransfusion is used to salvage blood loss in a variety of clinical settings but has never been used in the context of vaginal delivery. We describe the development and testing of a novel device for the collection, filtration and autotransfusion of blood lost due to PPH. The prototype device is inexpensive and easily operated so that it may be practically deployed in low resource settings. The device is comprised of a blood collection drape, a pump apparatus, three leukocyte reduction filters and a reservoir for filtered blood. Preliminary testing demonstrates efficacy of microbial load reduction of up to 97.3%. To reduce cost and improve safety, the device is modular in design such that the drape, tubing, filters and transfusion bag may be stored sterile, used once and discarded; while the pump apparatus may be used indefinitely without the need for sterilisation. Preliminary results indicate the device confers a low cost and potentially effective means of collecting, pumping, filtering and returning blood to a patient following PPH in settings that lack safe blood supplies. This device shows promise as a method of stabilising patients suffering of PPH in low resource settings until definitive treatment is rendered with the ultimate goal of reducing maternal mortality globally.