The correlation between muscles insertions and topography of break lines in pertrochanteric fractures: a comprehensive anatomical approach of complex proximal femur injuries

The purpose of our work was to verify the hypothesis that muscle insertions and ligament attachments have an impact on the course of typical break lines in the area of the trochanteric massif, i.e., to provide a more detailed description of the origins and insertions of the musculo-ligamentous apparatus on the surface of the proximal femur, and to find a potential morphological correlate between muscle insertions and ligament attachments to the proximal femur and the course of the break line in a typical pertrochanteric fracture. A detailed dissection of areas of trochanter major et minor, linea et crista intertrochanterica was performed in 50 anatomical preparations of the proximal femur, and the insertions of the muscular-ligamentous structures were described. The set of 600 radiographs were used to obtain projections of typical break lines on the proximal femur, and corresponding areas of exposed bone surface were identified in the anatomical preparations based on the projections and on 15 real specimens of patients after the pertrochanteric fracture osteosynthesis. Bone covered only with the periosteum, with no reinforcing elements of the origin or insertions of muscles or attachments of ligaments, represents the locus minoris resistentiae for beginning of fractures. Variability in the sizes and shapes of pertrochanteric fracture fragments also depends on variability of the locations and sizes of soft tissue attachment areas at specified sites on the proximal femur.