The Influence of Patient Age and Mechanism of Injury on the Type of Pelvic Fracture: Epidemiological Study

Abstract

PURPOSE OF THE STUDY The patients with pelvic ring injury involve two groups: 1) young and middle-age persons, mostly men, with serious injury to the pelvic ring due to high-energy trauma; and 2) older patients, mostly women, with osteoporotic fractures due to a simple fall. The aim of this study was to show significant differences in the selected epidemiological characteristics between these two groups. MATERIAL AND METHODS The group comprised 225 patients older than 15 years with pelvic fractures who were treated between January 1, 2007, and December 31, 2009. In this retrospective descriptive study, the patients' data on age, gender, mechanism of injury and a type of fracture according to the AO classification were retrieved and analysed. Categorical data at a level of significance of 5% were compared using the Chi-square test. RESULTS In the group reviewed there were 113 women and 112 men, with an average age of 51 years (women, 53 years; men, 49 years) in the range of 15 to 95 years. More men than women were in the age range of 15 to 60 years (with the difference being significant only in the sixth decade of life; p=0.043). In the age category of over sixty, women outnumbered men, and this was significant in the eight and ninth decades (p=0.023 and p=0.04, respectively). Significantly more men were involved in motorbike accidents (p=0.047) or had falls from heights (p=0.004) and particularly those at a worksite (p<0.001). Fractures due to a simple fall were significantly more frequent in women than men (p<0.001) and, generally, were most often found in the old-age category, in which women were eight years senior to men. Type A fractures were found in 58, type B fractures in 140 and type C fractures in 27 patients. The most frequent fractures (A2.2, p=0.054; B2.1, p=0.038) occurred more often in women and at a much higher age than in men (the age difference was 15 years in type A2.2 fractures and "only" 7 years in type B2.1 fractures). The patients who sustained either of these fractures in a simple fall were about 35 years older than those in whom these fractures were caused by high-energy trauma. DISCUSSION The fact that pelvic injuries most often occur in men at young or middle age has been confirmed by several epidemiological studies with a conclusion that age-related risky male behaviours play a significant role. The findings of this study showed that pelvic fractures due to simple falls were mostly found in old-age patients, with women eight years older than men. This provides evidence for the existence of two distinct groups of patients with pelvic fractures. The existence of two epidemiologically different groups of patients with pelvic fractures, in the authors' opinion, is demonstrated by a correlation of AO fracture type, patient gender and age in each group. A mere comparison of the age of patients indicates that older patients had mostly type A and B fractures. Unilateral fractures of the pubic ramus after a simple fall, which are regarded as related to osteoporosis, were recorded in a significantly higher number of women of the oldest age. The authors suggest that epidemiological studies of pelvic injuries should use the age of 70+ as an exclusion criterion in the patients with type A2.2 and B2.1 fractures. This will remove the bias of epidemiological data on patients with severe pelvic injuries, resulting from involvement of patients with osteoporotic fractures. CONCLUSION The evaluation of epidemiological data in this study allows us to conclude that younger men are those most frequently sustaining pelvic injuries due to high-energy trauma and that old age (80+) is characteristic for patients of both sexes, with female sex predominance, who have fractures due to simple falls. These findings give support to the concept that, in a group of patients with pelvic injuries, a subgroup with fractures different in terms of epidemiology and aetiology (osteoporotic fracture) can be identified.