Retroviruses expressing a fluorescent protein, Cas9, and a small guide RNA are used to mimic nonsense PTEN mutations from autism patients in developing mouse neurons. We compare the cellular phenotype elicited by CRISPR-Cas9 to those elicited using shRNA or Cre/Lox technologies and find that knockdown or knockout (KO) produced a corresponding moderate or severe neuronal hypertrophy in all cells. In contrast, the Cas9 approach produced missense and nonsense Pten mutations, resulting in a mix of KO-equivalent hypertrophic and wild type-like phenotypes. Importantly, despite this mixed phenotype, the neuronal hypertrophy resulting from Pten loss was evident on average in the population of manipulated cells. Having reproduced the known Pten KO phenotype using the CRISPR-Cas9 system we design viruses to target a gene that has recently been associated with autism, KATNAL2. Katnal2 deletion in the mouse results in decreased dendritic arborization of developing neurons. We conclude that retroviral implementation of the CRISPR-Cas9 system is an efficient system for cellular phenotype discovery in wild-type animals.

Aims Due to the recent rapid expansion of scooter sharing companies, there has been a dramatic increase in the number of electric scooter (e-scooter) injuries. Our purpose was to conduct a systematic review to characterize the demographic characteristics, most common injuries, and management of patients injured from electric scooters. Methods We searched PubMed, EMBASE, Scopus, and Web of Science databases using variations of the term “electric scooter”. We excluded studies conducted prior to 2015, studies with a population of less than 50, case reports, and studies not focused on electric scooters. Data were analyzed using t-tests and p-values < 0.05 were considered significant. Results We studied 5,705 patients from 34 studies. The mean age was 33.3 years (SD 3.5), and 58.3% (n = 3,325) were male. The leading mechanism of injury was falling (n = 3,595, 74.4%). Injured patients were more likely to not wear a helmet (n = 2,114; 68.1%; p < 0.001). The most common type of injury incurred was bony injuries (n = 2,761, 39.2%), of which upper limb fractures dominated (n = 1,236, 44.8%). Head and neck injuries composed 22.2% (n = 1,565) of the reported injuries, including traumatic brain injuries (n = 455; 2.5%), lacerations/abrasions/contusions (n = 500; 7.1%), intracerebral brain haemorrhages (n = 131; 1.9%), and concussions (n = 255; 3.2%). Standard radiographs comprised most images (n = 2,153; 57.7%). Most patients were treated and released without admission (n = 2,895; 54.5%), and 17.2% (n = 911) of injured patients required surgery. Qualitative analyses of the cost of injury revealed that any intoxication was associated with higher billing costs. Conclusion The leading injuries from e-scooters are upper limb fractures. Falling was the leading mechanism of injury, and most patients did not wear a helmet. Future research should focus on injury characterization, treatment, and cost. Cite this article: Bone Jt Open 2022;3(9):674–683.

Electric scooter (e-scooter) use and resulting injuries have grown exponentially since expansion into ridesharing in 2017. No study has described pediatric e-scooter injuries and focused on their impact in an adolescent cohort. Our primary purpose was to describe the epidemiology of admitted pediatric e-scooter injuries and compare them with existing literature on adults. We queried the National Electronic Injury Surveillance System for e-scooter injuries between 2015 and 2019 in patients 0-18 years old. Injuries caused by an e-scooter to a nonrider were removed. Patients admitted to the hospital were analyzed and weighted national estimates were calculated. A P value of <0.05 was considered significant. Nine hundred and two pediatric patients were treated for an e-scooter injury at an emergency department (ED) between 2015 and 2019. Among those admitted (n = 47), 72.3% were men, and the average age at injury was 11.3 years. Among all injuries (n = 56), the most common diagnosis was fracture (24/56, 42.9%). The 19% (9/47) of patients that experienced polytrauma were significantly older than those with single injuries (P < 0.001). ED admissions grew by 616% from 2017 to 2018. Children experience a greater rate of fractures and polytrauma from e-scooters compared to adults, but fewer facial injuries despite a similar rate of head trauma. The incidence of pediatric head injuries indicates a lack of helmet use similar to adults. Lawmakers should consider bolstering e-scooter regulations to decrease pediatric injuries.

Background: Although claims of increased injury rates with Thursday night National Football League (NFL) games exist, a paucity of data exist substantiating these claims. Purpose: To evaluate the effect of rest between games on in-game injury rates as it pertains to overall injury incidence, location, and player position. Study Design: Descriptive epidemiologic study. Methods: Data were obtained from official NFL game books for regular season games from all 32 teams for the 2013-2016 seasons. All in-game injuries recorded in official game books were included. Rest periods between games were classified as short (4 days), regular (6-8 days), or long (≥10 days). Overall observed injury rates per team-game were analyzed in relation to different rest periods using negative binomial regression. For results with significant overall findings, pairwise comparisons were tested using the Wald chi-square test. Exploratory secondary analyses were performed in a similar fashion to assess differences in injury rates for the different rest periods when stratified by anatomic location and player position. Results: A total of 2846 injuries were identified throughout the 4 seasons. There was an overall significant difference in injuries per team-game between short, regular, and long rest ( P = .01). With short rest, an observed mean of 1.26 injuries per game (95% CI, 1.06-1.49) was significantly different from the 1.53 observed injuries per game with regular rest (95% CI, 1.46-1.60; P = .03), but not compared with the 1.34 observed injuries per game with long rest ( P = .56). For player position, only the tight end, linebacker, and fullback group demonstrated significant differences between the injury rates for different rest categories. Quarterback was the only position with more injuries during games played on Thursday compared with both regular and long rest. This specific analysis was underpowered and the difference was not significant ( P = .08). No differences were found regarding injury rates in correlation with differences in rest periods with different injury locations. Conclusion: A short rest period between games is not associated with increased rates of observed injuries reported in NFL game books; rather, our data suggest there are significantly fewer injuries for Thursday night games compared with games played on regular rest. Future research correlating rest and quarterback injury rates is warranted.

BACKGROUND In the Spring of 2020, residency programs across the country experienced rapid and drastic changes to their application process as a result of the coronavirus disease 2019 (COVID-19) pandemic. In response, residency programs shifted to virtual events and began harnessing social media to communicate with applicants. AIM To analyze the changes in social media usage by orthopaedic surgery programs in response to the COVID-19 pandemic. METHODS Based on the 2019 residency and fellowship electronic database, accredited US orthopaedic surgery programs were reviewed for social media presence on Instagram and Twitter. Approximately 47000 tweets from 2011-2021 were extracted through the Twitter application programming interface. We extracted: Total number of followers, accounts following, tweets, likes, date of account creation, hashtags, and mentions. Natural language processing was utilized for tweet sentiment analysis and classified as positive, neutral, or negative. Instagram data was collected and deemed current as of August 11, 2021. The account foundation date analysis was based on the date recognized as the start of the COVID-19 outbreak in the United States, before or after March 1, 2020. RESULTS A total of 85 (42.3%) orthopaedic surgery residency program Twitter handles were identified. Thirty-five (41.2%) programs joined Twitter in the nine months after the 2020 covid outbreak. In 2020, there was a 126.6% increase in volume of tweets by orthopaedic surgery residency accounts as compared to 2019. The median number of followers was 474.5 (interquartile range 205.0-796.5). The account with the highest number of tweets was Hospital for Special Surgery (@HSpecialSurgery) with 13776 tweets followed by University of Virginia (@UVA_Ortho) with 5063 and Yale (@OrthoAtYale) with 899. Sentiment analysis before 2020 revealed 30.4% positive, 60.8% neutral, and 8.8% negative sentiments across tweets. Interestingly, the positive sentiment percentage increased in 2020 from 30.4% to 34.5%. Of the 201 ACGME-accredited orthopaedic residency programs on Fellowship and Residency Electronic Interactive Database, 115 (57.2%) participate on Instagram, with 101 (87.8%) identified as “resident”-managed vs 14 (12.2%) identified as “department”-managed. Over three quarters (77.4%) of Instagram accounts were created after March 1, 2020. The average number of followers per account was 1089.5 with an average of 58.9 total posts. CONCLUSION Our study demonstrates a substantial growth of Instagram and Twitter presence by orthopaedic surgery residency programs during the COVID-19 pandemic. These data suggest that orthopaedic residency programs have utilized social media as a new way to communicate with applicants and showcase their programs in light of the challenges presented by the pandemic.