BACKGROUND CONTEXT: A previous pilot study by our group demonstrated that nicotine administration via transdermal nicotine patch showed consistent serum nicotine levels whereas administration via the more commonly utilized mini-osmotic pump resulted in large variations in serum levels of nicotine of rabbits. In other work, we have previously demonstrated that nicotine delivered via a transdermal patch enhanced posterior spinal fusion rates in rabbits. This is contrary to studies published by other groups where nicotine administration decreased fusion rates.