Clinical outcomes of fractures affecting both the femoral neck and femoral trochanter

Some types of proximal femoral fractures have poor clinical results. Area classification is a comprehensive classification that can identify such "dangerous" fractures, because it can classify fractures that extend beyond the areas of conventional classifications. In this study, the outcomes of fractures affecting both the femoral neck and trochanter were investigated using Area classification. A total of 1042 proximal femoral fractures were investigated by Area classification and clinical outcomes. The proximal femur was divided into 4 areas by 3 boundary planes. A fracture only in the first area was classified as a Type 1 fracture; one in the first and second areas was classified as a Type 1-2 fracture. Cases with cut-out or greater than 10-mm telescoping of the internal fixator were defined as the Failure-group. The group other than the Failuregroup was regarded as the Success-group. The ratio of the Failure-group to the whole was defined as the failure rate. The distribution of Area classification between the Failure-group and Success-group differed (P<0.0001). Even in the 682 cases treated with osteosynthesis, the distribution of Area classification between the Failure-group and Success-group differed (P=0.0123), and the Failure-group had more Type 1-2, Type 3-4, Type 1-2-3, and Type 2-3-4 than the Success-group. Furthermore, when the number of areas that the fracture line involved increased, the failure rate rose (P=0.0413). Area classification was related to clinical outcomes of proximal femoral fractures. Fractures affecting both the femoral neck and trochanter had a high failure rate.