Substantial decrease in paediatric lower extremity fracture rates in German hospitals in 2017 compared with 2002: an epidemiological study

BACKGROUND: There are no recent studies on the frequency of paediatric lower extremity fractures in Germany. The aims of this study were to report fracture rates of paediatric lower extremity fractures treated in German hospitals in 2002 and 2017 and to detect changes over time as well as to evaluate the gender and age distribution for each fracture location. METHODS: Data from the German National Hospital Discharge Registry, which covers over 99% of all German hospitals, were used for this study. The absolute frequencies and incidence of lower extremity fractures as well as age at the time of fracture and gender were included in the data. The population was subdivided into four age groups: 0–4, 5–9, 10–14, and 15–19 years. The boy: girl ratio (BGR) for all fracture locations was calculated by dividing the absolute frequency of boys by that of girls. The fracture incidence in 2017 was compared with 2002 by calculating the incidence rate ratio (IRR). RESULTS: The total number of fractures decreased by 39.9% from 2002 to 2017. The most common fracture locations in 2002 were femoral shaft, tibial shaft, distal tibia, and lateral and medial malleolus; the absolute number of all these fractures was lower in 2017 than in 2002 in all age groups. The incidence of hip and thigh fractures, knee and lower leg fractures, and foot fractures decreased by 39.0, 41.1, and 33.3%. Proximal tibial fractures increased both in absolute numbers and in incidence in the age groups 0–4, 10–14, and 15–19 years (IRR ≥ 1.1). The overall BGR was 2.3 in 2002 and 2.0 in 2017, indicating that the number of girls relative to that of boys who suffered a lower extremity fracture was higher in 2017 than in 2002. Furthermore, the BGR of all fracture locations increased with age in both years. CONCLUSIONS: The number of paediatric lower extremity fractures treated in German hospitals in 2017 was significantly lower than that in 2002. However, the fracture frequency in girls decreased to a lesser extent than that in boys. The incidence of proximal tibial fractures increased.