An update on osteochondritis dissecans of the knee.

Osteochondritis dissecans of the knee (OCD) is a multifactorial pathology in where repetitive microtrauma plays a central role in the etiopathogenesis. Knee MRI is indicated in young, active patients who have knee pain and/or effusion, to make an early diagnosis and decide about treatment, according essentially to the MRI stability signs. The choice of treatment should be also tailored, based on the patient's skeletal maturity, as well as the size and location of the lesion. Conservative treatment with restricting sports activities is the first line treatment and often sufficient to ensure healing in patients with open physes. Surgical treatment depends on the persistence of symptoms after 6 months of conservative treatment and/or based on the development of signs of instability of the lesion. Stable lesions with intact articular cartilage may be treated by drilling of the subchondral bone aiming to stimulate vascular ingrowth and subchondral bone healing. Every attempt should be made to retain the osteochondral fragment when possible. Instable lesions should be fixed or "replaced" with salvage procedures to prevent the onset of early osteoarthritis in this young population. Furthers studies are needed to improve the knowledge and optimizing non-operative and surgical treatment and to develop noninvasive diagnostic tools to predict with more accuracy the fragment's stability.