It sounds like you have a condition called osteochondritis or osteochondral lesion of the talus. A corner of the talus breaks off and becomes a loose fragment of bone in the ankle joint. Trauma is the main reason why a corner of the talus breaks off and enters the joint space.
Other causes may include heredity, hormones, and loss of blood supply to the area. A small number of people seem to develop this problem for no apparent reason. Scientists are still scratching their heads over that and trying to figure out what’s really going on.
To answer your question, we don’t have a lot of studies to go on. And those studies that have been done comparing various treatments before and after 12 months have a limited number of patients in them.
But early identification of the problem is helpful in avoiding long-term complications. If the patient with a mild, stable lesion can be placed in a cast or walking boot with protected weight-bearing, the lesion may be able to heal itself.
If the problem goes undetected and untreated, it can become a chronic issue and then a delay in treatment can occur. The results may not be as good as if it were caught early and treated conservatively.
In cases of chronic lesions, or large, unstable defects, surgery can no longer be put off. Here’s where the timing of the more advanced surgeries (bone grafting or chondrocyte implantation) doesn’t seem to make a difference in the final results.
Outcomes in terms of pain, stiffness, tenderness, and gait (walking) pattern are the same whether implantation occurs within the first year of injury or sometime after 12 months have gone by. That information gives the patient and surgeon time to try more conservative approaches. When all else fails, it’s not too late to try one of these more advanced procedures such as you are having.