RAPID AND SUSTAINED RISE IN THE SERUM LEVEL OF HYALURONAN AFTER ANTERIOR CRUCIATE LIGAMENT TRANSECTION IN THE DOG KNEE-JOINT

Objective. To monitor changes in serum levels of hyaluronan (HA) in ex perimental canine osteoarthritis (OA), and to relate these changes to the level of HA in synovial fluid (SF) and/or to the rate of HA synthe sis by synovium. Methods. OA was induced in 16 dogs by anterior crucia te ligament transection; 7 dogs were sham operated, An immunoassay was used to measure HA levels in serum at various times postsurgery and i n SF from OA knees at sacrifice (Week 13 postsurgery). The rate of HA synthesis by synovium from both knees of 9 OA dogs and 5 sham operated dogs was measured at 13 weeks. Results. The serum level of HA showed a minor transient rise postsurgery in sham operated dogs. In all OA do gs, this rise was marked and sustained and correlated with the SF leve l of HA. Further, in OA dogs, the rate of HA synthesis by synovium was elevated in both the operated OA knee and the nonoperated knee.Conclu sion. The sustained rise in the serum level of HA in OA dogs appears t o be the result of increases in the rate of HA synthesis by synovium i n both the operated and nonoperated knees, and possibly in other synov ial joints.