The etiology and pathogenesis of SONK and postarthroscopic osteonecrosis remain highly controversial, and many theories have been proposed. Historically, SONK has been thought to occur secondary to ischemia, resulting in necrosis. Recently, however, a theory has been popularized proposing this entity to be a subchondral insufficiency fracture in osteopenic bone with no evidence of necrosis. These insufficiency fractures are thought to lead to fluid accumulation in the bone marrow, resulting in edema with focal ischemia and eventual necrosis. Factors predisposing to insufficiency fractures may include meniscal tears or meniscectomy, which can alter the native biomechanics and increase contact pressures and stress concentration on weightbearing areas. Postarthroscopic osteonecrosis seems to follow a similar pathogenesis. Therefore, the purpose of this study was to perform a detailed systematic review of the literature to evaluate studies that suggest etiological mechanisms for SONK in order to establish an improved understanding. We hypothesized that the etiology of SONK would be multifactorial.
Full Article: The Role of Meniscal Tears in Spontaneous Osteonecrosis of the Knee