The knee joint is made up of three bones – the thigh bone (femur), the shin bone (tibia) and the kneecap (patella). Fractures occurring around the knee are usually due to a significant traumatic injury in younger patients, and simple falls in older patients with poor bone quality. The fracture may involve the end of the femur (distal femur) or the upper part of the tibia (proximal tibia) at the knee joint. Fractures may also involve the patella.
Because these injuries often involve a split or disruption of the articular surface of the knee joint, they may lead to early arthritis due to rubbing of uneven joint surfaces. Patella fractures may disrupt the linkage between the thigh muscles and the shin bone and may therefore cause inability to straighten or extend the knee.
Diagnosis is usually made based on the history of the injury and physical examination. X-rays reveal the location and extent of the fracture, though often a CT scan is required in complex fractures involving the joint surface to more fully show the location of all fractures and assist in surgical planning.
Fractures around the knee frequently require surgery to repair the joint surface as anatomically as possible, restore stability to the knee, or repair the extensor mechanism of the knee. Dr. Boes can talk more specifically about the details of your particular injury and recommend appropriate treatment options.
For more information, visit http://orthoinfo.aaos.org/topic.cfm?topic=A00389.