Evaluation of the changes of P1NP and CTX in synovial fluid and blood serum of dogs with experimental osteoarthritis

Osteoarthritis is a degenerative and reparative process occurring in synovial joints. In the present study, collagen type I C-telopeptide (CTX) and procollagen type I N-terminal propeptide (P1NP) were measured in blood serum and synovial fluid of four cross-breed dogs with experimental CCL rupture. These biomarkers were selected as bone turnover biomarkers. The markers were measured on days 0, 14, 28, 90, and 180 post surgery. Statistical analysis showed significant increase in P1NP in both serum and synovial fluid. The CTX showed a significant increase in serum and a non significant increase in synovial fluid at the end of study. The changes in bone turnover biomarkers can be diagnostic in osteoarthritis. As time passes, the changes become more evident. Since the changes were the same in both serum and synovial fluid, measurement of the markers in serum is preferred as it is easier.