Fractures are breaks in the continuity of the hard outer layer (cortex) of bone. They are caused when the energy applied to a bone by an injury exceeds the strength of the cortex of the bone.
The most common fractures around the knee are fractures associated with the pulling off of ligaments such as the cruciate ligaments, fractures of the kneecap (patella) and fractures of the upper end of the shin bone (tibia). Fractures of small pieces of bone attached to large pieces of cartilage can also occur within the joint.
Many fractures will require fixation with screws, plates or wires or a combination of these. Fractures of the joint surface must be fixed very accurately or the joint is likely to develop arthritis later