Medical Care Management Based on Disaster Medicine for the Triathlon Events at the XXXII Olympiad and Tokyo 2020 Paralympic Games.

Planning the medical services for the triathlon competition at the 2020 Tokyo Olympic and Paralympic Games was predicted to be challenging because of possible last-minute changes related to the COVID-19 pandemic and abnormally high temperatures. Therefore, event planners organized and executed a disaster medical care plan, a plan for providing care during emergencies. Based on the basic medical plan for all venues provided by the Tokyo 2020 Organizing Committee, planners for the triathlon venue prepared a medical care plan according to the CSCATTT principles: Command and control, Safety, Communication, Assessment, Treatment, Triage, and Transport. After the event, planners evaluated the number of COVID-19, heatstroke, and injury cases at the venue. The events were conducted without spectators in July and August 2022 because at the last minute, planners held the event without spectators. The triathlon competition involved 638 individuals, including athletes and staff. In total, 7 cases of injuries, 3 cases of mild heatstroke, and 13 other cases were reported, with only 2 requiring emergency transportation. No cases of COVID-19 were reported from the triathlon venue, including during the observation period after the event. This medical plan was effective in preventing heatstroke and COVID-19 cases during the big event. Efficiently and effectively responding to various situations is possible in a shorter period by planning large-scale medical services for such special circumstances according to CSCATTT, a principle of disaster medical care.

Neighborhood-level socioeconomic factors moderate the association between physical activity and relative age effect: a cross-sectional survey study with Japanese adolescents.

BACKGROUND: Relative age effect is defined as a phenomenon where children born early generally perform better than children born later in the same cohort. Physical activity is an important factor that might be influenced by the relative age effect. Socioeconomic factors (e.g., parent's income, education level) are also associated with the adolescent's physical activity. However, no existing study has examined whether socioeconomic factors moderate the relative age effect on the adolescent's physical activity. This study aims to clarify whether and how birth month and socioeconomic factors relate to organized sports and physical activity among adolescents in Japan. METHODS: We conducted a questionnaire survey targeting 21,491 adolescents who live in a widespread neighborhood. We included 8102 adolescents (4087 males and 4015 females: mean age 13.1 ± 1.4) in the analysis. Based on the participants' birth months, we divided them into four groups (April to June, July to September, October to December, January to March). We asked participants to report their organized sports participation. Using the International Physical Activity Questionnaire for Japanese Early Adolescents, we identified their moderate to vigorous physical activity (MVPA). Neighborhood-level socioeconomic factors (areal deprivation, average annual income, education level) were analyzed based on national surveys, such as the population census. We performed multilevel logistic and linear regression analysis for organized sports participation and MVPA, respectively. Moreover, a simple slope analysis was implemented if the interaction between birth month and socioeconomic factor was significant in the multilevel linear regression analysis. RESULTS: Among males, relatively younger adolescents (adolescents who were born later in the same grade) were less likely to participate in organized sports activites (OR=0.90, 95% CI 0.82-0.97, p<0.05), while both males and females engaged in less MVPA (b=-0.54, b=-0.25, p< 0.01, respectively). We observed an interaction between birth month and socioeconomic factors. Among males in low-income neighborhoods, and females in more deprived neighborhoods, relatively younger adolescents engaged in less MVPA. CONCLUSIONS: Socioeconomic factors moderate the relative age effect on adolescents' physical activity. The relative age effect on adolescents' physical activity might be more likely to appear among adolescents from socioeconomically disadvantaged neighborhoods.

Association of Neighborhood Food Environment and Physical Activity Environment With Obesity: A Large-Scale Cross-Sectional Study of Fifth- to Ninth-Grade Children in Japan.

Objective: This study examined the relationship between neighborhood food and physical activity environment, and obesity among elementary and junior high school students in Japan. Methods: The participants were fifth- to ninth-grade children (n=7277), who were attending municipal schools in Japan. Percent overweight (POW) was calculated using their age, gender, height, and weight, which were collected through a questionnaire. A POW of < 20% was considered non-obese, while ≥ 20% was considered obese. Furthermore, using a geographic information system, we investigated the density of convenience stores, fast-food stores, casual restaurants, supermarkets and department stores, parks, sports facilities, stations, and intersections in the school district. Additionally, from the census, we obtained information regarding the population density of the municipality where the participants' schools were located. Multiple logistic regression analysis was used to examine the relationship between obesity and food environment (the food environment model), between obesity and physical activity environment (the physical activity environment model), and among obesity, food, and physical activity environment (the food and physical activity environment model). Results: In the food environment model and the food and physical activity environment model, the density of convenience stores showed a significant positive association. In the physical activity environment model, the density of stations showed a significant negative association. Conclusion: This study's findings can contribute to the development of appropriate community interventions for improving children's health in Japan and similar areas.

The relationship between sleep habits, lifestyle factors, and achieving guideline-recommended physical activity levels in ten-to-fourteen-year-old Japanese children: A cross-sectional study.

The current focus of meeting the physical activity guidelines for children and young people include preventing conditions such as high blood cholesterol, high blood pressure, metabolic syndrome, obesity, low bone density, depression, and injuries. However, the relationship between sleep habits and meeting physical activity guidelines is still unclear. This study aimed to assess this relationship among fifth- to eighth-grade (ages 10-14) Japanese children. This cross-sectional study included 3,123 children (boys: 1,558, girls: 1,565, mean age: 12.5 ± 1.2 years). Questionnaires were used to assess parameters such as moderate-to-vigorous physical activity per day, school and weekend night sleep durations, social jetlag, daytime sleepiness, napping, screen time, and breakfast intake. Participants were divided into an achievement and a non-achievement group depending on their physical activity guideline achievement status (i.e., whether they met the children's physical activity guideline of 60 min or more of moderate-to-vigorous physical activity per day). Then, to determine the sleep habits in relation to the children's achievement of guideline-recommended physical activity levels, multivariate logistic regression analyses were conducted. In fifth- and sixth-grade (ages 10-12) boys, an inverse association was observed between physical activity guideline achievement and daytime sleepiness. In seventh- and eighth-grade (ages 12-14) boys, physical activity guideline achievement was inversely associated with social jetlag and skipping breakfast. Additionally, in seventh- and eighth-grade girls, physical activity guideline achievement was inversely associated with inappropriate sleep duration on weekends and screen time. These results suggest that meeting the physical activity guideline is related to favorable sleep habits in Japanese children. However, their relevance may differ by school type and gender.

Long-term clinical and radiographic follow-up of total resection for discoid lateral meniscus.

PURPOSE: The purpose of this retrospective study was to analyze the effects of age at surgery on the clinical results, arthritic progression, and changes in lower limb alignment during long-term follow-up of total resection for discoid lateral meniscus. METHODS: A total of 37 knees in 32 patients were reviewed as a whole group and also after division into the following 3 groups according to the age at surgery: group A, 11 knees in patients aged less than 20 years; group B, 13 knees in patients aged 20 to 39 years; and group C, 13 knees in patients aged greater than 39 years. The mean age at surgery was 31.2 years (range, 9 to 52 years), and the mean length of follow-up was 14.5 years (range, 10 to 22.4 years). RESULTS: According to the scale of Ikeuchi, clinically excellent or good results at the final follow-up were found in 84% of the knees in the whole group, 91% of those in group A, 85% of those in group B, and 77% of those in group C. Moderate or severe narrowing of the lateral joint space was seen in 11% of the knees in the whole group, 0% of those in group A, 8% of those in group B, and 23% of those in group C. In an analysis of lower limb alignment, statistically significant postoperative lateral shifts of Mikulicz's mechanical axis were observed in groups B and C. CONCLUSIONS: The clinical results were satisfactory and the postoperative arthritic changes were mild in patients aged under 40 years. However, it is necessary to carefully monitor arthritic progression in patients who are aged over 19 years and have valgus deformities, because most of the knees in patients above this age became more valgus postoperatively. LEVEL OF EVIDENCE: Level IV, prognostic case series.

High tibial osteotomy that does not cause recurrence of varus deformity for medial gonarthrosis.

It is widely accepted that high tibial osteotomy (HTO) is an effective surgical treatment for medial gonarthrosis. However, long-term follow-up studies have revealed that the clinical results deteriorate over time and varus deformity often recurs. We performed barrel-vault osteotomy in HTO with a correction angle that did not cause arthritic progression in the medial compartment of the knee or recurrence of varus deformity. Thirty patients (44 knees) were followed clinically and radiographically for a minimum of 10 years (average, 11.4 years). We aimed for an average postoperative femorotibial angle (FTA) of 165.3 degrees (range, 162-169 degrees ) according to our method using a correction angle chosen on the basis of the so-called Mikulicz's mechanical axis. The clinical results were good in 30 (68.2%) knees, fair in 7 (15.9%) and poor in 7 (15.9%). Arthritic progression in the medial compartment was only found in 1 (2.3%) knee, while in the lateral compartment it was found in 17 (38.6%) knees. Of the knees with arthritic progression in the lateral compartment, six (35.3%) were classified as poor. The average postoperative FTAs were 164.3 degrees at 1 year, 164.0 degrees at 5 years and 163.5 degrees at 10 years after the operation, indicating that the knees tended to become slightly valgus over time. The clinical results were not poor after slightly overcorrected osteotomy was performed. Since overcorrection tended to occur, when the preoperative lateral tibial thrust was severe, HTO is not a good indication for such cases.

Osteochondritis dissecans of the knee: long-term results of excision of the osteochondral fragment.

This study aimed to show the results of osteochondritis dissecans fragment excision. We reviewed 85 patients (98 knees) with osteochondritis dissecans in a retrospective study of the results of merely excising the osteochondral lesion. Thirty-one knees were treated by only the removal of the fragment. Of these, it was possible to contact and examine 14 patients (14 knees); the average follow-up periods were 8.3 years (range 4.5-32 years). Knee function was evaluated according to the criteria of the International Knee Documentation Committee (IKDC), 12 knees in the 14 patients had no further symptoms and the 2 others had mild pain when going up- and downstairs. Roentgenograms at follow-up showed slight osteoarthritic changes. The preoperative femoro-tibial angle measured at surgery showed no marked change compared with that at follow-up. The study suggests that clinical and radiological results are good following removal of the osteochondral loose fragments are excised.

Percutaneous drilling of symptomatic accessory navicular in young athletes.

BACKGROUND: Results of percutaneous drilling for symptomatic type II accessory tarsal navicular bone are not determined. HYPOTHESIS: Percutaneous drilling of accessory navicular synchondrosis will induce or accelerate bone union between the accessory and primary navicular bones. Bone union of the synchondrosis leads to symptomatic relief. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Thirty-one feet of 29 patients with type II accessory tarsal navicular treated by percutaneous drilling were reviewed. RESULTS: Twenty-four feet (77.4%) were assessed as excellent, 6 (19.4%) as good, and 1 (3.2%) as fair. No feet were assessed as poor. Bone union was obtained in 16 (80%) of the 20 feet when the proximal phalanx of the great toe was immature and in 2 of the 11 feet when it was mature. CONCLUSION: Percutaneous drilling of the synchondrosis was effective for a symptomatic type II accessory navicular, especially in patients with immature proximal phalanx of the great toe.

Achilles tendon rupture associated with injury of the calcaneofibular ligament.

A 49-year-old man collided against an infielder when he slid into second base during a recreational baseball game. He was unable to continue in the game due to diffuse pain and swelling of his hindfoot. A rupture of the Achilles tendon was diagnosed incidentally on palpation and observation of a positive Thompson's squeeze test. Subcutaneous hemorrhage at the lateral aspect of the heel and a small bone fragment under the lateral malleolus on an anteroposterior plain radiograph indicated a fracture of the calcaneal wall. At surgery, a complete rupture of the Achilles tendon and an avulsion of the calcaneofibular ligament from the calcaneal wall were seen. Both injuries were surgically repaired, and the patient subsequently did well. The mechanism of injury was thought to be impact hyperdorsiflexion of the ankle with rupture of the Achilles tendon accompanied by an inversion injury. Using a literature search, it was found that this combination of injuries has not been previously reported.