Meniscal extrusion as booster of osteoarthritis

Meniscal extrusion (ME) has shown to play a critical but still unclear role in osteoarthritis (OA) development. ME has been described as an important risk factor in the progression of knee OA, as it is involved in the thinning of articular cartilage, joint space narrowing, spontaneous osteonecrosis of the knee and subchondral bone marrow lesions. Meniscal damage of any degree of severity could cause ME in both compartments, but it is commonly associated with severe meniscal tears or root tears mainly in the medial meniscus. Magnetic resonance imaging is the most commonly used imaging modality in the assessment of ME, while ultrasonography may represent a valid alternative with high sensitivity and specificity. Conservative treatment for ME includes physical therapy and rehabilitation to maintain range of motion, corticosteroid injections and intra-articular injections of hyaluronic acid to provide short-term relief of knee pain. The goal of this study is to review standards of current diagnosis and treatment of ME and its relationship to knee OA.