2 months. If you are referring to the sternotomy incision, that bone should be healed and you should be ok resuming full activity after 2 months. If you are having any discomfort after that time you need to see your doctor to make sure that you are healing, and that there are no complications.
10 weeks. Fracture healing progresses at a rate of 8 to 10% per week for a period of 10 to 12 weeks. Having bypass surgery does not affect the rate of healing. Non steroidal anti-inflammatory drugs (nsaids) and smoking are both associated with delayed fracture healing and heart problems. Although they may not accelearte fracture healing, vitamin d and calcium are important for healthy bones.