Objectives: The purpose of this study was to evaluate the relationship between exercise time and musculoskeletal problems and to determine the appropriate amount of exercise for children in both lower- and higher-grade levels of elementary and junior high schools.Materials and Methods: Mark-sheet-type questionnaires were distributed to and collected from all elementary and junior high schools in two cities. We collected 22,494 questionnaires in total. The relationship between exercise time and musculoskeletal problems was analyzed. The χ2 test and multivariate logistic regression analysis were used for statistical analyses.Results: The mean exercise time in school, in addition to physical education time, was 3.1 hours per week. In 56% of the children, the exercise time was less than 2 hours per week, and in 13% of the children, the exercise time was more than 10 hours per week. Although the rate of sports injury increased with an increase in exercise time, the duration of one-leg stand (a test of balance and muscle strength) also increased with an increase in exercise time. The cut-off values for sports injuries in boys/girls were 2.9/2.9 hours, 4.0/2.9 hours, and 7.5/4.2 hours in lower grade elementary school, higher grade elementary school, and junior high school, respectively.Conclusions: Although an appropriate amount of exercise improves one’s physical health and ability, excessive exercise leads to musculoskeletal problems. Approximately 7 hours/week of exercise is recommended for junior high school students. In elementary school, the exercise time should be carefully decided as the musculoskeletal system of the students is still immature.

Background: The use of prophylactic contralateral pinning for slipped capital femoral epiphysis (SCFE) remains controversial. This study evaluated the outcome of SCFE treatment and examined the use of prophylactic pinning.Methods: The study included 44 patients (33 men, 11 women; 54 hips [right, 31; left, 23]), with mean age of 12.9 (7.3–29) years, who underwent treatment between 1986 and 2017, with follow-up for more than 6 months. Patients were divided into 3 groups: group 1 had bilateral SCFE at first presentation, group 2 developed contralateral side SCFE during follow-up, and group 3 had unilateral SCFE until final follow-up. Three patients who received prophylactic pinning were excluded. Univariate and multivariate logistic analyses were performed.Results: Overall, 93% (50/54) of hips underwent positional reduction and in situ fixation and 7.4% (4/54) underwent open reduction. Mean follow-up period was 4.8 (0.5–25) years. Groups 1, 2, and 3 had 7, 3, and 31 cases, respectively. Sex, age, and follow-up period showed no significant differences among the groups. The Rohrer index was significantly higher in group 1, the affected side posterior sloping angle (PSA) was significantly higher in group 3, and the contralateral side PSA and percentage with endocrinopathy were significantly higher in group 2. In multivariate logistic analysis, age, sex, Rohrer index, affected side PSA, and endocrinopathy were significantly correlated with bilateral SCFE.Conclusion: We recommend prophylactic contralateral side pinning in patients with risk factors of obesity, high PSA before slipping, and endocrinopathy. Careful observation until growth plate closure is required in patients without risk factors.

Objective: To compare the outcomes of steroid-associated osteonecrosis of the femoral head in patients with systemic lupus erythematosus who underwent conservative treatment and concentrated autologous bone marrow aspirate transplantationMethods: Osteonecrosis of the femoral head was classified according to the Japanese Investigation Committee system. Concentrated autologous bone marrow aspirate transplantation was performed by aspirating the bone marrow from both iliac crests and then transplanting it to the necrotic area after the core decompression. Patients with >2-year follow-up after the concentrated autologous bone marrow aspirate transplantation in our institution (Group I) and those with >2-year follow-up after the first hospital visit in a cooperative institution (Group II) were included in this study. After a randomized matching based on age, sex, type, stage, and etiology, the collapse rate in pre-collapsed stages and total hip arthroplasty conversion rate in all stages were compared between the two groups.Results: After the matching adjustment, 33 pairs of hips were included. Preoperatively, 1, 2, 16, and 14 hips were classified as types A, B, C1, and C2, respectively, and 15, 13, 2, and 3 hips were classified as stages 1, 2, 3A, and 3B, respectively. The collapse rates in the pre-collapsed stages were 68% and 39% in Groups I and II, respectively. Total hip arthroplasty conversion rates were 33% and 45% in Groups I and II, respectively. However, Group I had significantly higher and lower conversion rates in stages 1 and 3, respectively (both P<0.05).Conclusion: Conservative treatment may be preferable in stage 1 hips. In addition, concentrated autologous bone marrow aspirate transplantation may prevent further collapse in stage 3.

Objective: In 2020, coronavirus disease-2019 (COVID-19) became the cause of a pandemic. In response, the Japan Sports Agency issued warnings about secondary damage to health, such as the threat to physical and mental well-being due to the lack of exercise in this situation. In this study, we report on cross-sectional and longitudinal examinations of standing trunk flexion to evaluate how temporary long-term school closures affected musculoskeletal function in elementary school students.Patients and Methods: All children in one public elementary school in T-city during the school years 2019 and 2020 were included in this study. A digital forward flexion meter was used to measure standing trunk flexion.Results: In this study, 284 (284/289: 98.3%) and 266 (266/274: 97.1%) children in school years 2020 and 2019, respectively, were found to have valid data for cross-sectional analysis. The standing trunk flexion did not show significant differences between grades or sexes. In the longitudinal analysis, the results of the comparison of standing trunk flexion in children for two consecutive years revealed significant differences only between grades 3 and 4 (P<0.05) and between girls in grades 3 and 4 (P<0.01), but no significant differences in other grades or among boys or girls were observed.Conclusion: Initially, we expected that there would be a difference in the results of functional assessment using standing trunk flexion depending on the period of absence from school. However, the results of this study showed no significant changes in standing trunk flexion. Moreover, since children’s musculoskeletal functions may be affected by various factors during the COVID-19 pandemic, they should be carefully monitored in the future.

Background: In Japan, in 2016, the School Health and Safety Act was revised and examination of extremities in addition to scoliosis became mandatory. Musculoskeletal examinations were subsequently started using a mark sheet-type questionnaire. In the present study, we aimed to analyze the relationship between physical findings and musculoskeletal problems and propose a preventive strategy for musculoskeletal injuries.Methods: In 2017, a total of 4,073 elementary and middle school students underwent direct musculoskeletal examination. In a direct examination, the following elements were included: torticollis; scoliosis; stiffness of the shoulder, elbow, hip, knee, and ankle; flexion and extension in standing position; flat foot; hallux valgus; and alignment of the upper and lower extremities. Of the 4,073 students who underwent direct examination in early 2017, only 3,754 were able to complete the mark sheet-type questionnaires in early 2018. A prospective longitudinal analysis of the data gathered was performed.Results: A total of 396 (11%) students had injuries. The ankle sprain/non-ankle sprain group comprised 119 (3%)/3,635 (97%) students, while the fracture/non-fracture group comprised 105 (2.8%)/3,650 (97.2%) students, respectively. Comparing the sprain group with the non-sprain group, ankle stiffness significantly correlated with ankle sprain in the univariable and multivariable analyses. Injuries occurred more frequently among boys, older students, students with stiff bodies, and students who were involved in sports activities of longer duration.Conclusion: Ankle stiffness was assumed to be a risk factor for ankle sprain. Stretching of the ankle might be effective for preventing ankle sprain. However, further interventional studies are needed to confirm this finding.

Objective: In 2016, Japan started conducting musculoskeletal examinations that included “limb status” of students as an essential item. Our institution implemented a unified musculoskeletal examination for all public elementary and junior high schools in T-city. In this study, we aimed to report the progress in the past 4 years.Patients and Methods: The Tsukuba Childhood Locomotive-Organ Screening Sheet (T-CLOSS), which is a questionnaire that includes some nationwide-recommended questions, was prepared and distributed to students. Results of the questionnaires were analyzed, and the orthopedic surgeon conducted examinations for the extracted items. From these questionnaires, the ratio of each item, rate of advisory for screening, and content of the advisory were investigated.Results: During 2016–2019, musculoskeletal examinations were conducted in every public schools, with nearly 20,000 students in T-city. The consultation advisory rate was 6.7% in 2019. Of the 524 students who received the third screening recommendation, the actual consultation rate was 248 (40.8%). After the third screening, the proportion of students requiring treatment and outpatient visits was 46.7% (n=248), which accounted for 1.2% of all elementary and junior high school students in the city.Conclusion: We reported the results of 4-year musculoskeletal examinations in a city. In our screening, we distributed a uniform questionnaire throughout the city, and orthopedic surgeons performed secondary examinations of identified students in all schools. This appears to be an advanced effort to prevent musculoskeletal impairment in students. We hope to conduct more sophisticated musculoskeletal examinations using our results, aiming at early detection, early treatment, and improvement of musculoskeletal function in elementary and junior high school students.