EFFECT OF NICOTINE ON THE RATE AND STRENGTH OF LONG-BONE FRACTURE-HEALING

Empirical clinical observation suggests that cigarette smoking has an inhibitory effect on long bone fracture healing, but this has not been proven scientifically. Forty female New Zealand White rabbits had mid shaft tibial osteotomies performed and plated. These were divided rand omly into two groups receiving either systemic nicotine or saline (pla cebo), Lateral radiographs were taken at 4, 6, and 8 weeks that showed a 17.2% average difference in callus formation between the two groups and a significant lag in formation of cortical continuity in the nico tine group. The rabbits were sacrificed 8 weeks after fracture, and he aling was compared biomechanically, Three (13%) fractures showed no cl inical evidence of union in the nicotine group, whereas all fractures in the control group healed. Biomechanical testing showed the nicotine exposed bones to be 26% weaker in three-point bending than were those exposed to placebo.