Objective:To compare and analyze the epidemiological characteristics of adult tibial plateau fractures in 5 provinces and cities in north China.Methods:Picture archiving and communication system (PACS) and medical record systems were used to search for clinical data of adult tibial plateau fractures which had been treated from 2010 to 2011 in 18 hospitals in 5 provinces and cities in north China (Beijing, Tianjing, Hebei Province, Shanxi Province and Inner Mongolia Autonomous Region). The patients included were divided into 14 age groups (one age group from 16 to 19 years, every 5 years as an age group from 20 to 79 years, and one age group ≥80 years). They were also divided into 2 groups according to the Schatzker classification, a simple fracture group (types Ⅰ-Ⅳ) and a complex fracture group (types Ⅴ-Ⅵ). The gender distribution, age distribution, and complexity of adult tibial plateau fractures were compared between the 5 provinces and cities.Results:A total of 2,845 patients were included, accounting for 1.8% (2,845/155,971) of all the adult fractures, 19.5% (2,845/14,569) of tibiofibular fractures and 29.1% (2,845/9,782) of intra-knee fractures at the same period. Their average age was 45.5 years, with the age group from 40 to 44 years accounting for the largest proportion. There were statistically significant differences between the 5 provinces and cities in north China in the male to female ratio ( P<0.05) but not in the age distribution ( P>0.05). In the age groups >44 years, the proportion of female patients increased gradually, reaching 70.0% (21/30) at the age group of ≥80 years, showing statistically significant differences between them ( P<0.001). There were significant differences between the simple and complex fracture groups in the gender and age distributions ( P<0.05), but not in the mean age at fracture ( P>0.05). The male patients in the simple and complex fracture groups showed a unimodal curve which peaked at the age group from 40 to 44 years. The female patients showed a unimodal curve which peaked at the age group from 55 to 59 years in the simple fracture group but lower bimodal curves which peaked at the age groups from 35 to 39 years and from 55 to 59 years in the complex fracture group. In both fracture groups, the proportion of female patients increased steadily with age beyond the age group from 40 to 44 years, showing significant differences by the linear trend test ( P<0.001). Conclusions:Tibial plateau fractures prevailed in both males and females between 40 and 44 years old. Simple and complex fractures showed different features in terms of gender and age.