EFFECT OF INTERMITTENT CIGARETTE-SMOKE INHALATION ON TIBIAL LENGTHENING - EXPERIMENTAL-STUDY ON RABBITS

We investigated the effect of intermittent cigarette smoke inhalation on the bone healing of tibial lengthening in rabbits, Thirty-eight mal e rabbits were divided into two groups of 19 animals each, The first g roup went through intermittent cigarette smoke inhalation, and the sec ond group did not go through intermittent cigarette smoke inhalation. Each animal's right tibia was lengthened 5 mm using an uniplanar lengt hening device, Five animals of each group were killed at 4, 6, and 8 w eeks postoperatively for biomechanical testing, and one animal of each group was killed at 2, 4, 6, and 8 weeks postoperatively for histolog ic study, Using the contralateral nonoperated tibia as an internal con trol, we found that torsional strength of the lengthened tibia of the smoke inhalation group was decreased significantly compared with the n on-smoke inhalation group, The mean percent of maximal torque at 4, 6, and 8 weeks were 22.0, 66.3, and 78.6%, respectively, in the smoke in halation group, whereas the mean percent of maximal torque were 48.0, 84.1, and 90.8% %, respectively, in non-smoke inhalation group (one-ta iled t test, p < 0.01, p < 0.01, and p < 0.05 at 4, 6, and 8 weeks, re spectively), Our histologic observations revealed that the granulation tissue resorption, bone formation, and remodeling were delayed in smo ke inhalation group, The results of this study suggest that intermitte nt inhalation of cigarette smoke delays, but does not prevent, the bon e healing in tibial lengthening.