Femur the medial, gives attachment to the fibular collateral ligament of the knee-joint. The femur develops from the limb buds as a result of interactions between the ectoderm and the underlying mesoderm, formation occurs roughly around the fourth week of development. By the sixth week of development, the first hyaline cartilage model of the femur is formed by chondrocytes. Endochondral ossification begins by the end of the embryonic period and primary ossification centers are present in all long bones of the limbs, including the femur, by the 12th week of development. The hindlimb development lags behind forelimb development by 1–2 days.
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