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, th e tibial cochlea, the proximal trochlea of the talus and the metatarsa l 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 macrosco pically and histologically. Synovial grooves developed on all joint su rfaces examined, but at different times. At some locations the develop ment of the grooves began prenatally. During the groove development th e same features were in principle observed on all joint surfaces: Dege neration and progressive thinning of the joint cartilage, invasion of connective tissue into the cartilage, cessation of the endochondral os sification, and depression of the groove area into the subchondral bon e. The findings indicated that the synovial grooves should be consider ed as being part of the normal morphology of the joints. In 4 animals aged from 3 weeks to 13 months dyschondroplastic (osteochondrotic) les ions were observed in the joint cartilage both inside and outside the groove areas on one or more joint surfaces.