People with arthritis — especially those with osteoarthritis and rheumatoid arthritis — are some of the most likely to need hip and knee replacements, making them especially vulnerable to the ill effects of smoking.
Two recent studies presented at the 2012 annual meeting of the American Academy of Orthopaedic Surgeons in San Francisco report smoking — past or present — is harmful for hip and knee replacement patients.
The first study looked at over 600 knee replacements in patients in their early 60s. The surgeries were performed between 2005 and 2009 at the Center for Joint Preservation and Replacement at Sinai Hospital of Baltimore and the Bonutti Clinic of Effingham, Illinois. Approximately 115 of the patients were smokers.
The revision rate for the surgeries — the number of operations that needed to be redone — was 10 times greater for smokers compared to non-smokers. Complications such as blood clots, abnormal heart beats and kidney failure were also more prevalent for smokers — 21% versus 12% for non-smokers.
The researchers did not see a significant difference between current smokers and patients who had smoked heavily in the past but since stopped. “It could be that the damage was already done,” says Dr. Michael Mont, director of the Center for Joint Preservation and Replacement. “If you were an alcoholic and stopped drinking, you could probably get your body back to normal. When you smoke and stop, you improve your health, but you still have build-up in your system. That may be why we didn’t see a difference.”
The second study looked at 535 hip replacements in 500 patients between the years 1999 and 2009. The surgeries were done by Joint Implant Surgeons Inc., a private practice in Ohio. The research team, lead by Dr. Adolph V. Lombardi, president of Joint Implant Surgeons, found that there were 33 failures at an average of 18 months after surgery — a 6.2% failure rate. When factoring in smoking history, the team found smokers had failure rates of 11% compared to 5.3% in previous smokers and 3.8% in non-smokers.
“This is the nuts-and-bolts reasons for failure,” Lombardi said in the presentation. “I think we should encourage our patients to quit smoking. It will reduce the risk, but not totally, and smoking cessation should be considered part of your preoperative education program.”
There are several reasons smoking hinders healing. Nicotine is a very potent constrictor, decreasing blood supply, which results in the surgery wounds receiving less oxygen and white blood cells. In turn, that can lead to an increased risk of infection.
Arthritis or not, Mont says smokers should call it quits. “Obviously quitting smoking is still important if you want to help yourself,” he says. “Too many Americans are smokers.”