The bone is separated at the fracture site, and there is an offset. Displacement can be measured in millimeters or centimeters, or as a percentage. A tibia fracture that is transverse with the distal end displaced by one-third of the cortex diameter has 33% posterior displacement (Fig. 1).

Displacement is always mentioned with reference to the bone end proximal to the fracture site. For example, a fracture of the tibial shaft where the distal fragment is sitting anterior by 50% of the cortical width would have 50% anterior displacement. Lateral, posterior, and medial displacement would also be described in this manner.

Angulation of the fracture site refers to the angle made at the apex of the fracture site. For example, in a tibia fracture, if there is a 30-degree bend at the fracture site, it would be considered 30 degrees angulated (Fig. 2).

The angulation is described where the apex of the angle points. For example, a tibia fracture that is pointing medially would be described as having 30 degrees of medial angulation, or one could say that the apex of the angle points medially to describe the fracture. A fracture may have both angular deformity and displacement. A fracture could be angulated without displacement or be displaced without angulation.

The fracture is enclosed by soft tissue, and the overlying skin is intact. These are the most common fractures.

The bone breaks through the skin. There are three types of open fractures: Type I is characterized by an inside-out puncture from the sharp edge of the bone pushing through the skin, resulting in a laceration of less than 1 cm. Blood may leak through these lacerations. These fractures can be treated as closed injuries. The wound also can be washed in a sterile environment in the operating room.