Surgical induced models of joint degeneration in the ovine stifle: Magnetic resonance imaging and histological assessment.

Background: The purposes of this study were to (1) validate and assess the reliability of a modified magnetic resonance semi-quantitative score (sheep Magnetic Resonance osteoarthritis Knee Score (sMOAKS)) to evaluate joint degeneration in the ovine knee and to (2) investigate whether the transection of the anterior cruciate ligament (ACL), isolated or in combination with meniscal injuries, reproduce the degenerative changes described in the meniscectomized sheep.

Methods: Twenty sheep were randomly subjected to one of the following injuries to induce osteoarthritis (OA): ACL transection (ACLt), mid-body transection of the medial meniscus, ACLt combined with complete medial meniscectomy and complete medial meniscectomy. OA assessment was performed eight weeks postoperatively with sMOAKS, Mankin and Osteoarthritis Research Society International (OARSI) histological scores.