OCD lesions can be tricky. My DD didn't have it in her ankle but in her knees. Neither healed with conservative treatment, and for her that was 3 months of no gymnastics and very limited weight bearing. Six weeks of no weight bearing was just to see if there was some healing. It also depends on the stage of the lesion. If the cartilage is actually broken, it doesn't heal by itself as there is no blood supply to the cartilage. If it is just soft, then there is the potential that it can heal. Age can also factor in, the older you are, the less likely it will heal on its own. But there's no way of knowing which lesions will heal with just conservative treatment.