The morphology of synovial grooves (Fossae synoviales) in joints of cattle of different age groups.

The joint cartilage of the head of the radius, the metacarpal bone, the tibial cochlea, the proximal trochlea of the talus and the metatarsal bone of 26 cattle in the age groups fetuses, 0 days, 2-5 weeks, 2-5 months, 7-13 months, 2-3.5 years, and 5-7 years were examined macroscopically and histologically. Synovial grooves developed on all joint surfaces examined, but at different times. At some locations the development of the grooves began prenatally. During the groove development the same features were in principle observed on all joint surfaces: Degeneration and progressive thinning of the joint cartilage, invasion of connective tissue into the cartilage, cessation of the endochondral ossification, and depression of the groove area into the subchondral bone. The findings indicated that the synovial grooves should be considered as being part of the normal morphology of the joints. In 4 animals aged from 3 weeks to 13 months dyschondroplastic (osteochondrotic) lesions were observed in the joint cartilage both inside and outside the groove areas on one or more joint surfaces.