Protective effects of corticosteroids on cartilage lesions and osteophyte formation in the pond‐nuki dog model of osteoarthritis

Abstract

The in vivo effects of corticosteroids on osteoarthritic (OA) lesions were examined in 12 dogs in which the anterior cruciate ligament had been sectioned. Six were treated with oral prednisone and 6 were treated with intraarticular (IA) injections of triamciaolone hexacetonide (TH), at surgery and 4 weeks later. Twelve other operated dogs received no treatment. All dogs were killed 8 weeks postsurgery. Four of 15 normal control dogs received IA TH injections. Operated untreated dogs developed significant cartilage lesions on the femoral condyles and tibial plateaus with prominent osteophytes. Operated dogs treated orally or with IA injections had a significant reduction in osteophyte size.Cartilage erosions on femoral condyles were observed in 25% of the untreated dogs, 8% of the dogs receiving oral prednisone, and none of the dogs receiving IA TH. In both groups of treated dogs, the size of the tibial plateau lesions was significantly reduced compared with the operated untreated dogs. Histologically, corticosteroids significantly reduced the severity of OA structural changes of the cartilage on both medial and lateral femoral condyles and tibial plateaus in operated animals, with the exception of the lateral plateaus of those

Effects of tenidap on canine experimental osteoarthritis i. morphologic and metalloprotease analysis

“…The reduction in the degree of synovial inflammation noted with tenidap is intriguing and was somewhat unexpected since intraarticular corticosteroid injections have not been shown to produce this effect (12,13). This contrast between the efficacy of tenidap in reducing synovial inflammation and the lack of such action with low-dose oral corticosteroids is of particular interest.…”

“…Studies have demonstrated that small doses of intraarticular corticosteroids, when administered under prophylactic conditions, can reduce the progression of cartilage erosions and osteophyte formation in this model (12,13). A recent report from our laboratory suggests that the action of corticosteroids is associated with a reduction in the synthesis of stromelysin by chondrocytes (12).…”

“…The animals were anesthetized with intravenous pentobarbital sodium (25 mg/kg) and intubated. The anterior cruciate ligament of the right knee was sectioned through a stab wound (13). The dogs were kept in animal care facilities within our hospital for 1 week after surgery and then sent to a housing farm, where they were left free to exercise in a large field for 4-6 hours every day.…”

“…The degree of osteophyte formation was graded by measuring the maximal width (mm) of the spur on each femoral condyle (13). The cartilage changes were graded separately in the medial and lateral femoral condyles and the tibial plateaus, using a dissecting microscope (Stereozoom; Bausch & Lomb, Rochester, NY), as previously described (13). Briefly, the depth of the erosion was graded on a scale of 0-4, as follows: grade 0 = surface normal in appearance; grade 1 = minimal fibrillation or a slight yellowish discoloration of the surface; grade 2 = erosion extending into the superficial or middle layers only; grade 3 = erosion extending into the deep layers; grade 4 = erosion extending to the subchondral bone.…”

“…The experimental canine OA model has proven to be informative in testing the effects of drugs on disease progression and on the main pathophysiologic mechanisms involved in cartilage degradation (12,13). Studies have demonstrated that small doses of intraarticular corticosteroids, when administered under prophylactic conditions, can reduce the progression of cartilage erosions and osteophyte formation in this model (12,13).…”