According to studies, smoking a pack of cigs a day inhibits bone growth, how many is too many cigarettes?

I broke my tibia 10/12/2006...a week later, I developed DVT that went undiagnosed until January of this year. I was put on coumadin at that time, and the swelling in the leg decreased significantly. From XRays, we know that the healing process has been slow, and union has not yet occurred in the closed, simple break across my tibia. My question is simple. I have read umpteen studies that state that smokers run a greater risk of disunion and slowed healing of bone. Only nonsmokers (those who have NEVER smoked) show a significant change in healing time from this type of injury. Former smokers are also slow to heal, the difference being a matter of 1.6 months longer for the smoker on average. This being the case, how many cigarettes is too many to smoke during the healing process? I am in a recliner, living on workman's comp and stressing in general, quitting smoking is very difficult. After reading the statistics, why should I? Apparently once I've smoked, my body is done.