Your doctor's advice is based on science. A recent study showed that ulnar osteotomy--a procedure to shorten the ulna bone along the inside edge of the wrist--is less successful for patients who smoke. Smokers took almost twice as long to heal as nonsmokers (seven versus four months). The bones in smokers' wrists were more likely to show long delays in healing or fail to improve in a year's time.
Why these disappointing effects? Researchers think that nicotine restricts the blood supply that bones need in order to heal. This does not mean that your surgery will be worthless. However, the benefits of surgery may take longer to kick in than they would if you kicked the habit. If you continue to smoke, you may have more luck with this surgery if your doctor uses a special grafting technique or keeps you in a cast longer afterward, to allow better healing.