Current Radiological Aspects of Subchondral Insufficiency Fracture of the Knee

   Subchondral stress insufficiency fracture of the knee is a new type of fracture that occurs in people of the older age group (from 50–55 years old) when exposed to a normal load on weakened bone trabeculae. In Russian sources, there is few information about this type of fracture. This is primarily due to the fact that initially the world and domestic medical communities designated this type of pathology as “spontaneous osteonecrosis of the knee”. In recent years, this term has been revised abroad and replaced by a more suitable one – “subchondral insufficiency fracture”. The etiology of insufficiency fracture is based on many diseases and conditions that lead to bone tissue weakening (osteoporosis, collagenosis, rheumatoid arthritis, post-radiation changes in bones, etc.). The main method for diagnosing this type of fracture is magnetic resonance imaging, since it is able to detect a fracture at any stage (especially at an early one). According to modern concepts, the terms “osteonecrosis” and “subchondral insufficiency fracture” require completely different approaches to the treatment. In the presence of complications, a fracture of insufficiency of the knee joint condyles threatens with subchondral collapse and secondary osteoarthritis, which leads to disability of a patient. Given the relevance of this medical problem, the aim of the review is to show the current state of literature data on the issue.