I have a stress fracture on the sesamoid bone. It has been 4 months and not healed. What are the chances of becoming active again after a bone graft?

Please be careful. With any procedure for a stress fracture of the sesamoid on the foot. Try conservative treatment to reduce the symptoms. The sesamoid may be not healed and you may achieve a symptom free status. Surgery shold be a true last resort. Surgery will alter your foot mechanics so be prepared to still modify shoewear.
In my hands excision. Is the way 2 proceed, but both have 2 b removed. I have never heard of bone grafting. Usually the sesamoid crumbles ; does not heal.