Last reviewed: September 29, 2026

For smoking, quitting is one of the few things shown to lower the risk. For marijuana, the evidence is less clear.

People who smoke have more wound problems and infections after a knee replacement, as well as more pneumonia and more returns to the hospital. The risk rises the more someone has smoked. People who quit in the past are still at somewhat higher risk than people who never smoked, but at lower risk than people who still smoke.

Quitting before surgery helps. In a trial of hip and knee replacement, people given counseling and nicotine replacement starting 6 to 8 weeks before surgery had far fewer complications, especially wound problems. Across all kinds of surgery, quitting at least four weeks beforehand lowered complications, and the benefit grew the longer people had quit. Programs with regular counseling worked better than brief advice. A guideline from the American College of Rheumatology and the American Association of Hip and Knee Surgeons suggests delaying a joint replacement to cut down on or stop nicotine, on low-quality evidence.

Nicotine patches and gum were part of the programs that worked, because they help people stop smoking. Whether nicotine on its own affects healing is less clear. In record studies, people who used chewing tobacco had more complications after knee replacement than people who used no tobacco, though fewer than smokers. People who used nicotine without tobacco, such as vaping, had more complications and infections after hip replacement. No study has looked at nicotine patches or gum on their own in joint replacement.

Some surgeons check with a blood test for cotinine, a breakdown product of nicotine. In one large joint replacement practice, about 1 in 7 people who said they had quit still tested positive. The test picks up nicotine from any source, including vaping, so it cannot tell smoking apart from nicotine patches or gum.

For marijuana, studies based mostly on insurance and hospital records disagree. Some found more blood clots, loosening of the implant, redo operations and medical complications in people who used it. Others found no difference. These studies often cannot separate marijuana from tobacco and other drug use. In a large study covering many kinds of surgery, people who had used marijuana in the month before needed more opioid pain medicine and reported more pain, while two knee replacement studies found no difference in opioid use. In trials, a THC pill and a CBD cream did not reduce pain or opioid use after knee replacement.

In general:

  • Tell your surgeon and the anesthesia team whether you smoke, vape, chew tobacco or use marijuana, and how much.
  • If you can, stop all nicotine before surgery. If you cannot, stopping smoking matters most. Ask your surgeon about a quitting program with counseling and nicotine replacement, starting at least four weeks before surgery.
  • If you use nicotine patches or gum, tell your surgeon before any nicotine test.

Drafted with AI assistance from published sources, reviewed and edited by Babak Sheikh, MD.

Sources:

This is general information about what published research shows. It is not medical advice and it is not about your situation. Reading it does not create a doctor-patient relationship with me. I am a retired orthopedic surgeon and I do not see patients. Talk with your own doctor before changing anything about your care. If something feels suddenly or seriously wrong, get medical care promptly rather than waiting.

This page is provided as is. I make no guarantee that it is accurate, complete or current, and medical evidence changes. Use of it is at your own risk.

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