This Issue's Rounds Question - "Define a Chopart Fracture" (responses to be published in next issue)

In the last issue of Body Cast, Rounds asked: “Why is bone and fracture/wound healing affected by smoking?”

The following responses were received:

From Mary Young and Tony Bellon:

The patients studied by Michael McKee’s orthopaedic research had undergone Ilizarov reconstruction, a procedure in which a circular frame is put around the leg allowing the bone to be held rigidly without having to implant hardware. “The new formation of bone depends on a adequate supply of blood and oxygen reaching that area,” he said in reporting at a recent meeting of the American Academy of Orthopaedic Surgeons.

The negative effects of smoking following Ilizarov reconstruction are so significant, he said, that he now insists candidates for the surgery must stop smoking first. “When someone comes to my office and needs a complex reconstruction of the tibia and they smoke, I tell them flat out, ‘You need to stop smoking, and when you do, we will do your operation’.”

Smoking has been shown to affect bone mineral density, lumbar disc health, the risk of hip or wrist fractures, and the dynamics of bone and wound healing. Nicotine gets in the way of healing because it constricts blood vessels that supply oxygen to the skin.

From Mary Young and Tony Bellon:
Smoking has long been known to have detrimental effects on the body contributing to the problems such as heart disease and lung cancer. Research has shown that smoking has significant effects on the bones.

Multiple studies have shown a significant difference in the healing time of bone between groups of smokers and non-smokers. A study from Northwestern University Medical School in Chicago , Illinois was preformed on 54 patients who were surgically treated for a specific wrist injury. Of these patients, 95% of the non-smokers healed completely while only 68% of the smokers healed completely. The average time until complete healing was more then two months longer in the smokers. Numerous other studies on patients with different injuries have shown a similar effect.

Bones are nourished by blood much like organs and tissues in your body. Nutrients, minerals and oxygen are all supplied to the bones via the blood stream. Smoking elevates the levels of nicotine in your blood and this causes the blood vessels to constrict. Nicotine constricts blood vessels approximately 25% of their normal diameter. Because of the constriction of the vessels, decreased levels of nutrients are supplied to the bones. It is thought that this is the reason for the effect on bone healing.

From Lori Macdonald and Blair Matheson:
Healing is affected by smoking since an adequate degree of oxygenation is necessary to form mature collagen, which closes wounds. Smoking reduces the blood flow and the amount of available oxygen in the tissues under the skin. Nicotine is a vasoconstrictor that reduces nutritional blood flow to the skin, resulting in tissue ischemia and impaired healing of injured tissue. Nicotine also increases platelet adhesiveness, raising the risk of thrombotic microvascular occlusion tissue ischemia. In addition, proliferation of red blood cells, fibroblasts and macrophages is reduced by nicotine. Bones are nourished by blood much like the other organs and tissues in your body. Nutrients, minerals and oxygen are all supplied to the bones via the blood stream. Smoking elevates the levels of nicotine in your blood and this causes the blood vessels to constrict. Nicotine constricts blood vessels approximately 25% of their normal diameter. Because of the constriction of the vessels, decreased levels of nutrients are supplied to the bones. It is thought that this is the reason for the effect on bone healing. Smokers’ average time until complete healing is more then two months longer then non-smokers’ healing time.

From Neuville Yao:
Many studies have shown that fractures/wounds tend to take longer to heal if the injured person has been smoking. Cigarettes can also increase the risk of blood clotting, which may further reduce blood flow. Breakdown products of cigarette smoke include carbon monoxide, formaldehyde, nitrosamines and benzenes which can damage the cells that form the bone itself and can interrupt the healing process after a fracture or bone injury.

Bones are nourished by blood much like the other organs and tissues in your body. Nutrients, minerals and oxygen are all supplied to the bones via the blood stream. Smoking elevates the levels of nicotine in your blood and this causes the blood vessels to constrict. Nicotine constricts blood vessels approximately 25% of their normal diameter. Because of the constriction of the vessels, decreased levels of nutrients are supplied to the bone, fracture /wound. It is thought that this is the reason for the effect on bone/wound healing.

If a fracture is sustained, it is of utmost importance that one must not smoke. Doing so will decrease the chances of recovering completely, lengthen the time spent on healing and make it less likely that one will be satisfied with the outcome.

Editor’s note:
Secondhand smoke also impairs the ability of specialized cells to migrate toward the site of the wound, resulting in slower healing or greater scarring ( University of California , Riverside Study). The study found that secondhand smoke altered the arrangement of the cells’ cytoskeleton, causing the fibroblasts to become more adhesive and less mobile. Fibroblasts are cells that play an important role in wound healing.

Responses were also received from L. Arseneau, T. Broughton, A. Crossman, P. Gaudet, C. Longphee, J. Maulucci, I. Mills, J. Movasseli, E. Oborowsky, E. Place, V. Robichaud, B. Sheppard, H. Wong, S. Woodrow and T.Yorke