Target tissue models: cartilage changes in experimental osteoarthritis in the dog.

Transection of the anterior cruciate ligament in the dog knee leads to a reproducible defined osteoarthritis (OA) with erosive cartilage loss, subchrondral sclerosis, and osteophyte formation, enabling studies of cartilage biochemistry before morphological changes are apparent. As early as 1 week after operation, menisci showed increased water content , 20% loss of galactosamine, and 40% loss of glucosamine. There was increased synthesis of larger proteoglycans (PG) at 3, 6, and 12 weeks, and the synthesis was greater in the menisci than the articular cartilage. there was no apparent impairment of the PG ability to aggregate with hyaluronate.