Your doctor will examine the lesion to determine the appropriate course of rehabilitation. The diagnosis is made from X-rays showing the lesion of the surface of the knee. Sometimes, an MRI is needed to see the damage in the underlying bone. Treatment is different for adolescents and adults. Younger patients may be treated with immobilization, which is not as effective in adults. If a large fragment is present and not detached in the joint, attempts at surgical repair may be necessary.