Osteochondritis dissecans is a condition where the blood supply to a part of the bone is cut off, denying the bone cells the nutrients from the blood. Some people who develop osteochondritis dissecans don’t experience any symptoms. Others, particularly older children, teens, and young adults who are active in sports, do develop symptoms that can include pain, “locking of the joint,” and swelling. Ultimately, movement could become quite restricted especially if the bone that is affected is the femur, the shin bone, where it meets the knee.
Doctors don’t know what causes osteochondritis dissecans of the knee but they do agree that symptomatic cases need to be treated as soon as possible to avoid any long-term damage and disability. Management, however, is controversial with doctors approaching it in different ways. Some doctors prefer more conservative treatments, while others prefer surgery. The authors of this article wanted to determine if the presence of asclerotic ring (hardened tissue in a ring shape) around the area of the lesion, would be able to tell doctors ahead of time how well the condition will heal.
Researchers looked back at the records of 85 patients (62 boys) who had been diagnosed with osteochondriti dissecans. They were divided by age at time of diagnosis: group 1 was under 12 years old (about 29 percent of the children), group 2 was between 12 and 15 years old (57 percent), and group 3 was 16 years and older (14 percent). By reviewing two different angled x-rays that had been taken when the patients were diagnosed, the researchers determined in which group of three the patients belonged:
– Stage 0: no sign of a sclerotic rim on any angle of x-ray
– Stage 1: signs of a sclerotic rim in one angle of x-ray
– Stage 2: signs of a sclerotic rim on both angles of x-rays
The patients were initially treated conservatively (restriction from sports) for about 10 months. Those patients whose x-rays did not show improvement after conservative treatment went on to have surgery. This surgery involved drilling through the sclerotic ring using arthroscopic surgery, surgery done through tiny incisions that the surgeon uses to insert long instruments and a camera.
Healing in the patients with stage 0 was 100 percent, after 12 months, without surgery. Those with stage 1 healed without surgery in 36.4 percent of cases, with surgery in 63.6 percent. Among patients with stage 2, only 13.5 percent of cases were healed conservatively.
The authors concluded that the presence of the rim on x-ray can help predict if a patient will heal spontaneously, with conservative treatment, or will need surgery.