Early Low-Grade Knee Osteoarthritis in Sheep (Ovis aries) after 6-Weeks of Total Unilateral Meniscectomy: A Radiographic Evaluation

Different new potential biologic agents have recently been studied to control knee joint osteoarthritis (KOA). Hence, animal models are one of the most important foundations studies to assess early safety and efficacy before human clinical trials. This study aimed to evaluate the radiographic progression of stifle joint osteoarthritis (OA) after lateral meniscectomy. A total of 14 skeletally matured sheep (Ovis aries) were subjected to total lateral meniscectomy and evaluated for radiographic cranio-caudal and mediolateral projections at the 6^th and 12^th week after surgery. Low grade OA was seen radiologically by osteophyte formation at the 6^th week, followed by intra-articular mineralization and subchondral sclerosis at the 12^th week after meniscectomy. There was statistically non-significant difference in the radiographic scores between 6^th and 12^th week after meniscectomy. In conclusion, total lateral meniscectomy in the ovine stifle joint could create low grade OA as early as 6 weeks, confirmed radiologically by osteophyte formation. Further studies are needed to evaluate the correlation between radiological and clinical findings.