Structure of the ligamentum synoviale infrapatellare in the dog

The knee joint of the dog is frequently the subject of surgery if the cruci ate ligaments or the menisci are injured. In the knee joint of the dog we f ind a ligament, which is spread out between the anterior part of the fossa intercondylaris ossis femoris and the corpus adiposus infrapatellaris. This ligamentum synoviale infrapatellare has not previously been described and represents a homologous structure to the plica synovialis infrapatellaris o f human knee joint. Just like the latter and just like the cruciate ligamen ts it is a rudiment of a septum articulare genu, which is spread out betwee n an articulatio femorotibialis and an articulatio femorofibularis in the e arly phylogenesis of tetrapods. The ligamentum synoviale infrapatellare of the dog consists of a stratum synoviale and a stratum spinosum, which inclu des blood vessels, nerves, many collagenous fibres and some elastic fibres. We do not find evidence for sensory nerve endings or corpuscular receptors . Therefore a severing of the ligament during knee joint surgery does not a ffect the proprioceptive potential of the knee joint.