What can make a bone island or bone lesion appear in xray of knee? I'm worried. Dr said they werent. 2 come back in 6 months to check it. I never went

If concern followup. Bone island is circumscribed usually ovoid area of dense normal bone that does not progress and is symptom free. If radiologist not sure of diagnosis but believes probably benign , follow up X-ray used to assess stability or progression.