Antibiotics after total joint replacement

Do joint replacement patients need antibiotics before dental work?

Traditionally, orthopedic surgeons universally recommended patients with joint replacements take a dose of antibiotics prior to dental work. This practice was generally supported by the American Academy of Orthopedic Surgeons. Recently, this recommendation has come into question with the American Dental Association stating that routine use of antibiotic prophylaxis following total joint replacement is not necessary.

Why the controversy?

Simple. We do not have sufficient data to make a strong recommendation backed up by science. The incidence (regardless of cause) of total joint infection is quite low at around 1-2%. When a problem occurs very infrequently, testing an intervention requires an enormous study to show an effect. Such a study simply has not been done. 

Let's look as some more data. While the bacteria implicated in the majority of total joint infections are staphylococcus species, which are mainly found on the skin, infections can also occur due to streptococcus species. The predominant bacteria in the mouth are streptococcus species. We know that bacteremia (bacteria present in the bloodstream) occurs during and after dental work. Whenever bacteria are present in the bloodstream, there is concern that they can be deposited on "at risk" material such as artificial heart valves and total joint replacement prostheses.  The tendency for bacteria to be deposited is likely higher in areas of increased and/or turbulent blood flow. Dental bacteria have been isolated from tissues deep within the body. And documented total joint infections due to dental bacteria have indeed been reported. Even native (non-replaced) joints can become infected as a result of oral bacteria following dental work.

Although based mainly on a few case reports, my conclusion is that oral bacteria routinely enter the blood stream during dental work, and it is possible that a deep prosthetic joint infection can result. 

So why the controversy? There are different perspectives.

First, orthopedic surgeons know that an infected total joint replacement is a big deal. It usually requires more surgery, sometimes multiple operations and long-term IV antibiotics to cure. A cure is not guaranteed, and even when cured, return to pain-free function is not guaranteed. 

Second, dentists. Since there is not overwhelming evidence linking dental work to total joint infections I believe the issue has been minimized a bit by the dental community. I feel the American Dental Association has overstepped the science when stating antibiotic prophylaxis is not indicated prior to dental work.  This conclusion was essentially based on a single case-control study. To make such a conclusion, a properly conducted, prospective randomized study on a huge population is required. Dentists do not directly see or have to take care of a total joint infection and therefore may under-estimate the magnitude of such a problem. Perhaps also distancing the dental field from orthopedic infections could be felt to minimize liability in such cases. Interestingly, most local dentists actually encourage prophylactic antibiotics in spite of the ADA recommendations. 

Third, population health. Antibiotic overuse is not without consequence. There are multi-drug resistant bacteria that have evolved in part due to the tremendous volume of antibiotic medication used worldwide. (Of course the vast majority of antibiotic use is in veterinary medicine and food production, which is clearly a topic for another blog posting.)

Fourth, the total joint replacement patient. Antibiotics can be associated with negative side effects, allergic reactions, and secondary infections. So we need to carefully balance the risks and benefits. As I have outlined above, this is challenging because the risks and benefits have not been clearly defined scientifically.

Here is my approach. I recommend all of my total joint patients take a single dose of prophylactic antibiotics prior to dental work for a minimum of 2 years following surgery. 2 years is significant because we know there is increased bone metabolic activity (increased and turbulent blood-flow) around the total joint prosthesis during this time.  If a standard-risk patient wants to use antibiotic prophylaxis in this way indefinitely, I would not deny them the antibiotics after carefully discussing with them the risks and benefits. I recommend any high-risk patient (immunocompromised, diabetic, cancer, rheumatoid arthritis, etc) take a single dose of prophylactic antibiotics prior to dental work forever.  

With this approach, I am clearly biased in favor of my patients over the general population. In other words I feel that the single antibiotic dose I prescribe to my patients every six months is unlikely to have a major negative effect and also very unlikely to make a major contribution to worldwide bacterial resistance. Antibiotics are used in far greater quantities in the veterinary medicine and food industries, and are also inappropriately used in viral illnesses where they will have no benefit. Although prosthetic joint infection is rare at the population level, sparing an individual patient such a negative experience is a tremendous benefit. 

When I eventually undergo a joint replacement, based on my current understanding of the issues, I plan on using prophylactic antibiotics forever. 

---