EFFECTS OF TRIAMCINOLONE ACETONIDE ON AN IN-VIVO EQUINE OSTEOCHONDRALFRAGMENT EXERCISE MODEL

The objective of this study was to determine the effects of intra-arti cularly administered triamcinolone acetonide (TA) in exercised equine athletes with carpal osteochondral fragmentation, Eighteen horses were randomly assigned to each of 3 groups, An osteochondral chip fragment was created in one randomly chosen intercarpal joint of each horse, B oth intercarpal joints in the placebo control group (CNT) horses were injected with intra-articular administration (IA) of polyionic fluid, Both joints in the TA control group (CTA CNT) horses were treated with 12 mg of TA in the intercarpal joint without an osteochondral fragmen t, and the opposite intercarpal joint was injected with a similar volu me of polyionic fluid. The TA treated group (TA TX) horses were treate d with 12 mg of TA in the joint that contained the osteochondral fragm ent and the opposite intercarpal joint was injected with a similar vol ume of polyionic fluid. All horses were treated IA on days 13 and 27 a fter surgery and exercised on a high speed treadmill for 6 weeks start ing on Day 14. Horses in the TA TX group were significantly less lame than horses in the CNT and TA CNT groups, Horses in either TA CNT or T A TX groups had lower total protein, and higher hyaluronan, and glycos aminoglycan concentrations in synovial fluid than did those in the CNT group. Synovial membrane collected from subjects in TA CNT and TA TX groups had significantly less inflammatory cell infiltration, subintim al hyperplasia and subintimal fibrosis compared to the CNT group, Arti cular cartilage histomorphological parameters were significantly bette r from the TA CNT and TA TX groups compared to the CNT group, In concl usions, results from this study support favourable effects of TA on de gree of clinically detectable lameness, and on synovial fluid, synovia l membrane, and articular cartilage morphological parameters, both wit h direct intra-articular administration and remote site administration as compared to placebo treatment. The clinical use of IA administered TA in horses may be therapeutically beneficial in selected cases of o steochondral fragmentation and osteoarthritis.