2002 Volume 48 Issue 3 Pages 154-160
To determine whether there are paths for fracture lines, along which the cortical bone of long bones tends to split, a rabbit femur was split with a chisel and the course of the fracture line was investigated. Macroscopic observation of the rabbit femur confirmed that the course of the fracture line of the split bone has a constant direction. Microscopic cross-sectional observation showed that the fracture line ran along the curve of the cementing line, haversian lamella, or both. Microscopic examination of longitudinal sections showed that the course of the haversian canal was nearly parallel to the long axis of the bone. Furthermore, small cavities in the bone were also arranged parallel to this direction.
We thus confirmed that the fracture line tends to occur along lamellar structures or areas with weak physical and bond strength.
