CHICAGO– Among its many evils, smoking is detrimental to bone and connective tissue. Several studies presented at this year’s annual meeting of the American Academy of Orthopedic Surgeons show that smoking raises the odds of poor outcomes in common orthopedic procedures.

In short, smokers are much less likely to benefit from orthopedic surgeries like hip replacements and fracture repairs, and more likely to have complications.

Hip replacement patients who smoked experienced a higher rate of surgical revision, according to one study presented at AAOS. In a second paper, researchers found that smokers undergoing orthopedic treatment for pain experienced no benefit. A third study concluded that smokers had a higher rate of non-union and longer healing times after surgery.

“Nicotine-mediated vasoconstriction is considered to be the primary etiology of these effects, and we can postulate that decreased blood flow to the operative site results in decreased oxygenation of tissue, which can subsequently lead to soft-tissue and wound-healing complications,” said Bhaveen H. Kapadia, MD, orthopedic research fellow in the Center for Joint Preservation and Replacement at Sinai Hospital, Baltimore. Dr. Kapadia presented the hip replacement study.

Do-Overs

Dr. Kapadia and colleagues reviewed record for all hip replacements performed at Sinai between 2007 and 2009, and found that 110 of the patients were former or current tobacco users, with a mean age of 55. These patients were compared to a control group of non-smokers.  

They found that 8% of the smoking patients required a surgical revision within 46 months of the original procedures, compared to 1% of those who did not smoke. In five of the smoking patients, surgical revisions were required because of infection, while four revisions were done to address pain and component loosening. Of those patients who continued to smoke, six out of 65, or 9.2%, had revisions; in former smokers the number was two out of 45, or 4.4%.

Caleb J. Behrend, MD, a resident in training at the University of Rochester, New York presented data from large study of 6,779 patients who received treatment for painful spinal disorders. Nearly 9% of the patients over age 55, and 23.9% of those under 55 were smokers at the time they sought treatment.

The patients were asked to subjectively assess their pain during treatment. Researchers found that non-smokers had less pain than patients who smoked, regardless of age. In addition, non-smokers and patients who quit smoking during treatment experienced clinically meaningful reduction in pain, but those who continued smoking during treatment had no such improvements.

Those patients in the Rochester study who quit experienced an average reduction of pain by 1.5 points on a ten-point scale, which was statistically and clinically significant.  

“There’s kind of a myth that smoking makes smokers feel better,” said Dr. Behrend. “They may think so, but it certainly isn’t helping them if you actually look at the data. The clinical science shows very profound association between smoking and other chronic pain problems, such as leg and central back pain.”

Fracture Complications

Smoking had a negative effect on rates of bone union following fracture repair procedures, as well as recovery time following surgery, according to a metanalysis presented at the AAOS meeting.

The adjusted odds of non-union was 2.3 times higher in smoking patients than in non-smokers, and mean healing time for all fracture types was 30.2 weeks in smokers, compared to 24.1 weeks in non-smokers. However, this metanalysis did not show a significantly higher rate of infection among smokers.

The report was based on data from 18 studies between 1993 and 2011, representing 6,480 patients, 1,457 of whom were smokers at the time of surgery.

“The main direction for future research is to look at the effects of smoking cessation programs which can be instituted at the time of fractures,” said Mara L. Schenker, MD, an orthopedic surgery resident at the University of Pennsylvania in Philadelphia, who presented the metanalysis.

“This context is not like elective surgery where we can say to the patients in advance that they need to quit smoking. In this case, the patients come in and they’re injured, so we want to look at the effects of implementing a smoking cessation program at the time of surgery,” explained Dr. Schenker.

In general, orthopedic surgeons have recognized the detrimental effects of smoking on the musculoskeletal system, and many of them strongly recommend that whenever possible, patients should participate in smoking cessation programs prior to orthopedic surgery.