Stable fracture & Displaced fracture: In a displaced fracture, the broken ends of the bone are separated and do not line up correctly. The normally smooth joint surface may also be disrupted. This type of fracture often requires knee replacement surgery to put the pieces of bone back together.
Comminuted fracture: In this type of fracture, the bone shatters into three or more pieces. Depending on the specific pattern of the fracture, a comminuted fracture may be either stable or unstable.
Open fracture: In an open fracture, the bone breaks in such a way that bone fragments stick out through the skin or a wound penetrates down to the bone. An open fracture often involves damage to the surrounding soft tissues and may take a longer time to heal.
Open fractures are particularly serious because, once the skin is broken, there is a higher risk for infection in both the wound and the bone. Immediate treatment is required to prevent infection.