In vivo protective effects of prophylactic treatment with tiaprofenic acid or intraarticular corticosteroids on osteoarthritic lesions in the experimental dog model.

We examined the in vivo effects of prophylactic intraarticular corticosteroid injections and nonsteroidal antiinflammatory drugs (NSAID) (tiaprofenic acid) oral administration on cartilage lesions of osteoarthritis (OA) and osteophyte formation in 18 dogs in which the anterior cruciate ligament had been sectioned. Six of the dogs received no treatment; 5 had 3 injections of 5 mg triamcinolone hexacetonide at 0, 4 and 8 weeks postsurgery; and 7 were treated orally with 5 mg/kg/day tiaprofenic acid. The untreated dogs developed cartilage lesions on the tibial plateaus and femoral condyles with prominent osteophytes on both lateral and medial condyles. The number and size of the osteophytes were significantly reduced in the triamcinolone treated dogs (p less than 0.0001). Moreover, both triamcinolone and tiaprofenic acid treated groups showed a decrease in the grade and size of tibial plateau lesions, compared to the untreated dogs. There was a similar and statistically significant decrease in lesion size when the treated dogs (about 50 mm2) were compared to the untreated dogs (77 mm2). Histological studies revealed that both drugs also significantly decreased the severity of OA structural changes of the cartilage on both femoral condyles and tibial plateaus, although the response to triamcinolone was more pronounced. Our data confirm the effectiveness of prophylactic treatment with corticosteroids and tiaprofenic acid in preventing the progression of OA lesions in the dog model.