Background: Many studies have reported injury characteristics of individual traumatic situations. However, a comparative analysis of specific risks is meaningful to better understand injury characteristics and help establish injury-prevention measures. This study was conducted to investigate and compare injury characteristics in children and adolescents by various outdoor traumatic situations. Methods: Outdoor traumatic situations were determined and classified into physical activity-related injury (n = 3,983) and pedestrian (n = 784) and passenger (n = 1,757) injuries in traffic accidents. Home injury (n = 16,121) was used as the control group. Then, the characteristics of each outdoor trauma were compared with 1:1 matched indoor trauma (among home injuries); each outdoor traumatic situation’s predisposing risk for the injured body part, injury type, and injury severity were analyzed; and changes by age of frequency ranking among physical activity-related injuries were investigated. Results: Outdoor trauma showed higher risks for limb injuries (injured body part), fracture and muscle/tendon injuries (injury type), and severe injuries (severity) than indoor trauma. Various outdoor traumatic situations presented different predisposing effects on injury characteristics. Among physical activity-related injuries, bicycle injury was commonest across all ages, and playing activities were common causes for injury for individuals of age < 9 years, whereas sports activities overwhelmed the common causes thereafter. Conclusions The findings would help to better understand the specific injury risk of various outdoor traumatic situations and may potentially facilitate the establishment of more effective injury-prevention measures.

Background: In the Korean medical system, the severity classification for a specific disease depends primarily on its nationwide admission rate in tertiary hospitals. Inversely, one of the important designation criteria for a tertiary hospital is the hospital's treatment ratio of patients classified as having a specific severe disease. Most diseases requiring pediatric orthopaedic surgery (POS) are not currently classified as high severity in terms of disease severity. We investigated the admission rates for the representative POS diseases in tertiary hospitals and compared these rates with those for adult orthopaedic surgery (AOS) diseases. Methods: Seven POS diagnoses and three AOS diagnoses were selected based on frequency of admission. Nationwide sample data were used to investigate the admission rates for these representative diagnoses from 2008 to 2017. Results: Six of the seven frequent POS diagnoses presented high admission rates in tertiary hospitals (62.5–92.3%). In contrast, all frequent AOS diagnoses presented low admission rates in tertiary hospitals. Conclusion The admission rates of frequent POS diagnoses in tertiary hospitals are high.Considering that these rates are the most important factors for the classification of disease severity, POS diseases seem to be underestimated in terms of severity. This may lead to a tendency for tertiary hospitals to intentionally reduce the admission of children with POS diseases. As a result, these children may not receive appropriate professional care. Therefore, for the disease severity, POS diseases should be classified differently from general AOS diseases by using different criteria reflecting the patient's age.

Background: Many studies have reported injury characteristics of individual traumatic situations. However, a comparative analysis of specific risks is meaningful to better understand injury characteristics and help establish injury-prevention measures. This study was conducted to investigate and compare injury characteristics in children and adolescents by various outdoor traumatic situations. Methods: Outdoor traumatic situations were determined and classified into physical activity-related injury (n = 3,983) and pedestrian (n = 784) and passenger (n = 1,757) injuries in traffic accidents. Home injury (n = 16,121) was used as the control group. Then, the characteristics of each outdoor trauma were compared with 1:1 matched indoor trauma (among home injuries); each outdoor traumatic situation’s predisposing risk for the injured body part, injury type, and injury severity were analyzed; and changes by age of frequency ranking among physical activity-related injuries were investigated. Results: Outdoor trauma showed higher risks for limb injuries (injured body part), fracture and muscle/tendon injuries (injury type), and severe injuries (severity) than indoor trauma. Various outdoor traumatic situations presented different predisposing effects on injury characteristics. Among physical activity-related injuries, bicycle injury was commonest across all ages, and playing activities were common causes for injury for individuals of age < 9 years, whereas sports activities overwhelmed the common causes thereafter. Conclusions The findings would help to better understand the specific injury risk of various outdoor traumatic situations and may potentially facilitate the establishment of more effective injury-prevention measures.

Background: Ogden type IV tibial tuberosity fractures, defined as a type of fracture with posterior–inferior metaphyseal extension (Salter-Harris type II variant), are uncommon but challenging pediatric fractures. The purpose of this study was to investigate the clinical and radiological presentation and associated surgical outcomes. Methods: Ten previously healthy patients who had been surgically treated at the authors’ institution between 2015 and 2018 with at least 2 years of postoperative follow-up were included. Demographic, clinical, and radiological characteristics and treatment/ follow-up data were investigated. Results: All included patients were male. All injuries resulted from jump-landings. Unacceptable remaining angular deformity after closed reduction, particularly increased posterior tibial slope angle, was the leading cause of surgery. All preoperative magnetic resonance images (MRIs) showed entrapped periosteum on the anteromedial side of the proximal tibial physis. Surgical removal of the entrapped periosteum achieved successful reduction. Metaphyseal fracture angles between the fracture plane of the metaphyseal beak and the posterior tibial condyle on the axial image of MRI were relatively constant, with an average of 24.3° ± 6.0°. Mean bone age at the time of trauma was older than mean chronological age (16.4 ± 1.0 years vs. 14.6 ± 1.1 years, respectively; p = 0.005).All patients reached skeletal maturity within 2 postoperative years, with little posttraumatic residual height growth (mean, 1.6 ± 0.7 cm from injury to skeletal maturity). At final follow-up, no patients showed significant angular deformity, tibial length discrepancy, or functional deficit. Conclusions In healthy adolescents, Ogden type IV tibial tuberosity fractures typically occur by jump-landing injuries, when they have little residual growth remaining. Therefore, accurate fracture reduction was required because of limited remodeling potential.Patients with unacceptable reduction should be investigated for entrapped periosteum on the anteromedial side of the physis because it was the primary obstacle in achieving adequate reduction.