A fracture occurs when a bone breaks and the fragment of the bone pushes against the adjacent bone (which could be another bone, tendon, ligament, etc.) This pushes the bone out of its socket, where it then becomes dislodged from the bone carrier (the spinal column). If the bone carrier is an extensor muscle, the force that causes the bone to break is biomechanical forces due to movement of the upper body and the downward acceleration of the lower body at the time of impact. However if it is a functional muscle, than mechanical forces may cause it to break.
The types of fractures that we see in osteoarthritis can be classified according to their location and the type of tissue damaged. These can be broken bones that are open or closed (these tend to be painless fractures), fractures that are medullary (cracked bone), fractures that are referred (crushed bone), and fractures that are subluxation-determined. An open fracture of the foot has an outer and inner crack depending on which way they are coming in. Medullary fractures have a depression of the bone right below the bone, while subluxation-determined fractures have a crack that comes out of the bone. Broken bones treated with open surgery need to be supported with a bone graft, while those fractured in the medulla need to be surgically replaced with a cricoarytenoid bone graft.
In most of the cases of fractures that occur in the upper leg, the fracture will heal without any intervention for weeks or months at a stretch. However, if the fracture is a medullary fracture and it causes a severe deformity of the bone it can be treated aggressively by making an incision into the leg above the ankle and taking out the bone. This may mean that there is a need to put a screw or some other type of fixation to hold the bone in place as the broken piece falls out. In fracture of the upper leg that is referred, the doctor may remove a small part of the bone to check for problems and make sure that the fracture does not cause further damage. It is important to note that fractures of the upper leg that are referred do not need to be immobilized for long periods of time, as this will only aggravate the wound and make the healing process much more complicated.