There isn’t an exact answer to this question. The American Cancer Society reports that within 20 minutes of smoking cessation, blood pressure and pulse improve. By eight hours, the oxygen levels in your body will increase and carbon monoxide will decrease.
Within 24 hours, your risk of a heart attack is reduced. From two weeks to three months, there is improved blood flow and lung function. By the end of nine months, damaged cells in the body and lungs have regrown new ones. At the end of a year, your risk of heart disease is reduced to half of a smoker.
Most doctors suggest waiting three to six months. This depends on your ability to handle the pain and the condition of your spine. If a fusion is needed right away to protect your spinal cord, stop smoking now. Even the short-term change will improve your bone healing.