Epidemiology, patterns, and mechanisms of pediatric trauma: a review of 12,508 patients

Unintentional injuries are a significant health risk for children and adolescents. According to estimates by the World Health Organization, more than 830,000 under18s are killed in accidents worldwide every year [1]. In Germany, accident-related deaths among children and adolescents have been declining for years, but in 2020 traumatic injuries were still the second most common cause of death among children aged 1 to 15 [2]. Injuries in childhood and adolescence are also a frequent cause of hospitalization. According to the German Federal Statistical Office, accidents are the most common cause of hospitalization between the ages of 5 and 19 and the second most common cause between the ages of 1 and 4 [3].

The morbidity and mortality of children involved in accidents not only pose great challenges for those treating them but also long-term consequences, like physiological and economic aspects, must be taken into account [4‐6].

Numerous studies report incidence and mechanism of severely injured children [7‐11]. However, only few reports are found on all children requiring treatment for injury [12‐14].

This study was done to provide important information on the incidence, type, and mechanism of injury in children in order to help in developing prevention strategies.

This study was a retrospective exploratory review at a Level One Trauma Center in Germany. Every patient between 0 and 14 years of age who was treated for a trauma in our emergency department (ED) between January 2015 and December 2019 was identified and included in this study. Exclusion criteria were only patient age over 14 years and admission to the ED due to conditions other than trauma.

Patient demographics, time and month of presentation, type and mechanism of injury, and need for surgical care were examined. Patients were stratified in age groups babies up to 1, toddlers between 1 and 3, preschoolers between 4 and 6, young school children from 7 to 10, and young adolescents between 11 and 14 years of age. All mechanisms of injury were recorded and classified. Injuries were classified as fractures, distortions, lacerations, joint dislocations, bruises, burns, and multiple injuries or others. The exact body regions were recorded for all injuries. All injuries were analyzed in terms of mechanism, necessity of surgical treatment, and time of presentation in the ED.

The mechanisms of injury were classified into 8 categories:

A total of 12,508 patients were included in this study, of which 7302 were male and 5206 female. In all age groups, most patients were male. The age group with the most patients was young teenagers between 11 and 14 with a total of 3489 patients (27.9%). The demographic data are shown in Table 2. The age group distribution shows two peaks at a very young age between 1 and 3 years and again between 11 and 14 years (Fig. 1).

In our study, in all age groups male children were more frequently affected by unintentional injuries than females, which is in line with most epidemiological studies [11, 12, 15‐17]. This might be associated with a higher exposure to risky sport activities and a different pattern of behavior [12, 16, 18]. The age distribution of patients showed two peaks at ages 1–3 and 10–13 years. Age was hypothesized to have a significant effect on the pattern of physical activity, which in turn affects the injuries associated with physical activity. Ruffing et al. as well as Voth et al. described similar results with peaks in early ages as well as teenagers [16, 17]. In our study, leisure activities, including playground, showed a peak within preschoolers and school-aged children up to 10 years of age. A decrease in incidence was subsequently observed. In older adolescents over 11 years of age, the most common cause of accidents was sport-related activities, which was also observed in other studies [19, 20]. Similar results were found for accidents at home. Al Rumhi et al. and Chini et al. reported that children aged 1–6 and 1–5, respectively, were more likely to visit the emergency department because of accidents at home [21, 22]. Many studies suggest falls as main mechanism for unintentional injuries, especially in young children. This includes falls from low heights or while walking or running [12, 19, 23]. In our study, falls while walking or running were included in leisure activities. Falls from objects, like climbing frames, chairs, and stairs, are a common mechanism in among all ages and often describe the most common cause of accidents in children [12, 19, 20]. With regard to adolescents, many studies describe an increasing incidence of RTA as pedestrians or passengers with high mortality [13, 24]. Especially in developing countries, RTA is described as a major cause of injuries and mortality in older children and adolescents [14, 24, 25]. Interestingly, in our study, no significant increase in injuries associated with RTA at older ages can be seen. In fact, even at the age of 11–14 years, a slight decrease in injuries due to RTA is found. Gong et al. showed similar results with the highest incidence of RTA at the ages between 3 and 6 [26]. The reason for this is probably that many studies include children and adolescents up to 18 or 20 years of age. It is believed that it is only at this age that patients start using motorized vehicles and are more likely to be involved in a traffic accident [7, 10, 24]. Although not the most common mechanism of injury, all deaths in this study are associated with road traffic accidents. Most studies suggest RTA as mechanism with the highest mortality rate among children and young adults with a mortality rates between 0.3% and 8.5% [7, 11‐14]. In this study, the rate of severely injured children with an ISS > 16 was low. A comparable study from Germany with 15.300 patients reported an overall rate of children with an ISS > 16 of 0.5% [16]. Furthermore, the mortality rate in the present study was only 0.03% with 4 deaths, which is significantly lower than in comparable studies. Since our hospital, as a level 1 trauma center, is the only one in the nearby area that treats severely injured children, it is difficult to explain the low mortality rate. The hospital is not located in a major city which could lead to lower rate of fatal RTA due to less traffic in general. Additionally, children over the age of 14 are excluded in this study. It is assumed that patients at that age might be less likely involved in accidents in or on motorized vehicles, as already mentioned.

In terms of injuries, all deaths associated with RTA were caused by severe brain injury. This goes in line with most studies saying that the head is the most vulnerable body part, especially in young children [11, 12, 17, 26]. In the present study, the head was the most common body part for lacerations and second most for bruises. It has been shown that especially the disproportionately large head is affected more frequently in young children than in advanced age [16, 17]. Fractures were third most common injuries with peak incidences in school-aged children. Rennie et al. and Randsborg et al. show in a large epidemiological study about fractures in children a bimodal distribution with peaks at the ages of 6–8 and 10–14 with a significant drop in girls over the age of 12 [27, 28]. Similar results were found in our study with a decline in the incidence of girls over 11 years. Furthermore, the prevalence of the various fractures was remarkably similar between the study by Ruffing et al. and the present study. Thus, the distal radius/ulna followed by the metacarpal and fingers were found to be the most common locations of fractures in children [17]. Most common mechanisms for fractures were leisure activities as well as falls. This goes in line with epidemiological studies [19, 27, 29], whereas some studies suggest RTA as most common mechanism resulting in fractures in children [11]. Concerning sports-related activities, Randsborg et al. mentions soccer as being the most dangerous sport with high incidences of distal radial fractures [28]. Not surprisingly, the most common fractures requiring surgical treatment were forearm and humerus fractures. Further injuries were joint dislocations with the nursemaids elbow being the most common one with the highest prevalence at the age between 1 and 3 years. Similar to previous studies, female predominance was found with a ratio of 1.76:1 [30, 31]. Second most common dislocation was the patella dislocation. Studies suggest that between 50 and 70% of patellar dislocations occur while exercising or during other sports-related activity [32, 33]. We found similar results in the present study with the highest prevalence in sports-related activities.

Seasonal as well as time differences could be found in the study. In average, more patients were treated on the weekends than on weekdays. Most patients were admitted to the ED during the late afternoon and early evening hours. In fact, a large percentage of patients were treated in the out-of-office hours. Naqvi et al. reported similar findings with considerably more admissions during the evening with the highest levels of attendance between 5 and 8 pm [11, 19]. Randsborg et al. suggested that the time of admission relates with the season. They found that most admissions during the winter season are around noon, while most admissions in summer are in the late afternoon [28]. In the present study, most admissions were during spring and summer months between May and July. A significant drop in admissions was found in August, which could be explained by the school holidays and many families traveling during that time. Similar results were reported by Ruffing et al. [17].

Suspicion of child abuse was raised in 4 cases and shows an overall low incidence compared to similar studies. Naqvi et al. reported an incidence of 3.8% of suspected child abuse in their study [11]. All patients with suspected child abuse showed typical injuries around the head and uncommon fractures for the age. Typical characteristics described in the literature include patient age less than 1 and head injuries and strangulation marks that may indicate possible child abuse [34, 35].

This study has several limitations. This was a retrospective single-center study. Therefore, the epidemiological data are limited to one area. Some merging of variables had to be done to make the amount of data manageable. This could have resulted in loss of important information. Although the total number of patients is large, some subgroups are small and thus can only be insufficiently included for statistical calculations.

Most injuries in children are minor in nature and do not require further surgical treatment. The pattern of injury as well as the mechanism of injury varies between the different age groups. Head injuries remain the most dangerous injuries with a high mortality rate in all ages. The leading cause of fatal trauma was traffic accidents. Although in most cases the mechanism is obvious, suspicion of child abuse should be kept in mind. Peak times in the late afternoon and evening and summer months should be taken into consideration of personnel planning.