Reported COVID-19 Incidence in Wisconsin High School Athletes in Fall 2020.

OBJECTIVE: To describe the incidence of COVID-19 in Wisconsin high school athletes and investigate the relationship of COVID-19 incidence with sport and face mask use. DESIGN: Retrospective survey. SETTING: High schools across Wisconsin during September 2020. PATIENTS OR OTHER PARTICIPANTS: Athletic directors representing 30 074 high school athletes with or without SARS-CoV-2. MAIN OUTCOME MEASUREMENT(S): The COVID-19 rates among athletes, counties, states, as well as school instruction type (virtual versus in person), sport type, and face mask use were assessed. Reported athlete case rates were compared with the county's general population and associations between COVID-19 incidence and sport type and face mask use, adjusting for each school's county incidence using multivariable negative binomial regression models. RESULTS: The COVID-19 incidence rates for 207 of 244 responding schools were 32.6 cases per 100 000 player-days. Reported case rates for athletes in each county were positively correlated with the county's general population case rates (ß = 1.14 ± 0.20, r = 0.60, P < .001). One case (0.5%) was attributed to sport contact by the reporting schools. No difference was identified between team and individual sports (incidence rate ratio [IRR] = 1.03 [95% CI = 0.49, 2.2], P = .93) or between noncontact and contact sports (IRR = 0.53 [0.23, 1.3], P = .14). Outdoor sports had a lower incidence rate than indoor sports, although this finding did not reach statistical significance (IRR = 0.52 [0.26, 1.1], P = .07). No significant associations were found between COVID-19 incidence and face mask use during play for those sports with greater than 50 schools reporting on face mask use (P values > .05). CONCLUSIONS: The incidence of reported COVID-19 among high school athletes was related to the county incidence, and most cases were attributed to nonsport contact. A lower COVID-19 incidence in outdoor sports approached statistical significance. The lack of a significant benefit demonstrated for face mask use may be due to relatively low rates of COVID-19 in Wisconsin during September 2020. Further research is needed to better define COVID-19 transmission risk factors during adolescent sport participation.

Are you missing a concussion by watching American football? Video analysis of ball location in a Division 1 football program.

OBJECTIVE: Action in a football game occurs quickly. Medical staff can miss a sport-related concussion (SRC) if they do not observe it directly. The objective of this study is to determine if SRCs occur more frequently at ball than away from ball during gameplay. Game-specific concussion statistics can enhance medical provider care of athletes. METHODS: We used gameplay videos of an NCAA Division I football program to analyze SRCs and determine the primary tackler or ball handler during each concussion play. We compared the relative risk of SRCs for the primary ball handlers/tacklers to that of the other 10 players on the same team during that play. RESULTS: Over 10 seasons, 26 SRCs occurred at ball for the primary ball handler/tackler position (0.22 SRCs/game) versus 16 away from ball (0.13 SRCs/game). The relative risk of an SRC according to exposure (at ball) vs. no exposure (away from ball) was 16.2 (CI 8.7-30.2, P < .05). Special teams had more SRCs away from ball than at ball, but this was not significant (relative risk 3.32, CI 0.90-12.3, P > .05). CONCLUSIONS: The study provides medical staff guidance to more efficiently identify in-game SRCs and supports evidence for rules changes.

Video Analysis of Concussion Exposures in a National Collegiate Athletic Association Division I Football Team.

BACKGROUND: Research into improving player safety of sport-related concussion (SRC) in American football has been an ongoing endeavor. In an attempt to better understand the incidence of SRCs in American football, research has focused on the characteristics of SRC during gameplay. Determining SRC specifics and assessing them quantitatively can help identify high-risk scenarios and predict exposure risk. PURPOSE: To identify and assess the incidence of SRCs in a National Collegiate Athletic Association football team by comparing field location, player positions, collision partners, and player cues. STUDY DESIGN: Descriptive epidemiology study. METHODS: We used physician sideline reports of diagnosed concussions from a Division I football team from September 2010 to December 2018. Game videos were analyzed to identify the field location where the SRC occurred, collision partner, and player behavior postconcussion. The incidence of in-game SRCs by position was also assessed. We used the "words of estimative probability" model to categorize each concussion as certain, almost certain, probable, or even on the basis of our confidence in identifying them using game film. RESULTS: This study examined 44 SRCs that occurred over 9 seasons. The SRC incidence was significantly higher in the middle defense (5-20 yards from the line of scrimmage) compared with all other field locations (relative risk, 2.46; 95% CI, 1.14-5.29; P < .05). In-game collision partners were most commonly defensive backs. The most common player cue was a hand to helmet/face mask. The positions with the highest SRC incidence by athlete-exposure, game position, and position play belonged to the defensive backs, wide receivers, and running backs. CONCLUSION: The middle defense had a significantly higher incidence of SRCs than all other field locations. We pose a new method to categorize concussions during video analysis by using words of estimative probability. Knowledge of SRC gameplay characteristics can potentially guide the medical staff and medical observer to better identify them.

Periarticular Injections in Knee and Hip Arthroplasty: Where and What to Inject.

BACKGROUND: Periarticular injections have become a valuable adjunct to multimodal pain control regimens after knee and hip arthroplasties. Injection techniques vary greatly among surgeons with little standardization of practice. METHODS: We performed an extensive literature search to determine where nociceptive pain fibers are located in the hip and the knee and also to explore the pharmacology of periarticular cocktail ingredients. RESULTS: Large concentrations of nociceptors are present throughout the various tissues of the knee joint with elevated concentrations in the infrapatellar fat pad, fibrous capsule, ligament insertions, periosteum, subchondral bone, and lateral retinaculum. Less empiric evidence is available on nociceptor locations in the hip joint, but they are known to be located diffusely throughout the hip capsule with elevated concentrations at the labral base and central ligamentum teres. Local anesthetics are the base ingredient in most injection cocktails and function by blocking voltage-gated sodium channels. Liposomal anesthetics may offer longer duration of action over traditional anesthetics. Nonsteroidal anti-inflammatory agents and corticosteroids block peripheral production of inflammatory mediators and may desensitize nociceptors. Opioid receptors are present in lower densities peripherally as compared with the central nervous system, but their inclusion in injections can lead to pain relief. Sympathetic drugs can provide adjunct effects to periarticular cocktails to increase duration of action and effectiveness of medications. CONCLUSION: Targeting specific sites of nociceptors may help to further decrease pain after knee and hip arthroplasties. Altering periarticular cocktail ingredients may aid in multimodal pain control with injections.