Bird feet and legs only a small extension of the cnemial crest. In grebes both a normal patella and an extension of the cnemial crest are found. The fibula is reduced and adheres extensively to the tibia, usually reaching two-thirds of its length. Only penguins have full-length fibulae. The bird knee joint between the femur and tibia (or rather tibiotarsus) points forwards, but is hidden within the feathers. The backward-pointing "heel" (ankle) that is easily visible is a joint between the tibiotarsus and tarsometatarsus. The joint inside the tarsus occurs also in some reptiles. It is worth noting here that the name "thick knee"
Triple tibial osteotomy tibia with respect to the femur, hyperextension of the stifle joint and internal rotation of the tibia. The cranial cruciate ligament is thought to be able to resist a force equivalent to four times the weight of the dog before it ruptures, but often the ligament is weakened by arthritis that is present in the joint. Arthritis infers inflammation of the joint; in this condition there is the production of a joint fluid that is less viscous and therefore less able to absorb shock than normal fluid. Joint fluid's other role is to provide nutrition to the cartilage and the