Long-held practice patterns are hard to change, but the latest evidence regarding antibiotic prophylaxis for patients with prosthetic joints suggests that AP is not only unnecessary but potentially harmful. Bryan D. Springer, MD, Larry M. Baddour, MD, Thomas M. Paumier, DDS
More than 1 million hip and knee replacements are performed annually in the US, and an estimated 7 million people are living with a total joint replacement. By 2030, it is estimated that more than 4 million arthroplasty procedures will be performed yearly. A recent national poll reported that over 40% of dentists see patients with prosthetic joints multiple times per week.
The perception of conflicting guidelines from the American Academy of Orthopedic Surgeons (AAOS) and the American Dental Association (ADA) over the last 15 years has led many orthopedic surgeons and dentists to practice defensive medicine, defaulting to using antibiotic prophylaxis (AP) on a regular basis. More than 90% of orthopedic surgeons currently recommend AP for patients with total joint arthroplasty undergoing dental procedures. The confusion among dentists and orthopedic surgeons stems from six different information statements or guidelines from the ADA and AAOS in the last 25 years, often based only on a few well-done studies, but sometimes with conflicting information.
Recent guidelines on antibiotic prophylaxis The most recent ADA Clinical Practice Guideline (CPG) published in the Journal of the American Dental Association (JADA) in 2015 states, “In general, for patients with prosthetic joint implants, prophylactic antibiotics are not recommended prior to dental procedures to prevent prosthetic joint infection.” In 2017, the AAOS released appropriate use criteria (AUC) that identified a very narrow group of patients for whom it would be appropriate to consider using antibiotic prophylaxis. This cohort includes patients with comorbidities such as being immunocompromised or diabetic and having had a previous joint infection. The AAOS AUC states “… it would be reasonable to assume that most patients will fall outside of these criteria and therefore lay outside the confines of our strict definitions … and therefore do not need antibiotic prophylaxis.”
An awkward position for patients
Despite the general agreement of recommendations from the ADA CPG and AAOS AUC, patients are often told to use AP by their orthopedic surgeon but may be advised by their dentist that it is not necessary. This puts patients in the awkward situation of having to decide for themselves who they should believe and what they should do.
Concerns about periprosthetic joint infection
Since the publication of those guidelines, more recent and robust clinical evidence has emerged regarding the possible association between invasive dental procedures (IDPs) and development of periprosthetic joint infection (PJI). These studies call into question the routine use of AP for IDPs for anyone with a prosthetic joint and should result in a fresh look at this practice by a new guidelines committee. In the meantime, we should be practicing evidence-based medicine, with orthopedic surgeons and dentists delivering a consistent message to patients.
PJI studies
A 2017 case-control propensity-matched study in Taiwan looked at more than 250,000 patients who had a knee or hip arthroplasty and identified 57,000 who had undergone a dental procedure matched against nondental procedure controls. A subgroup analysis consisted of 6,500 dental patients who had used AP matched against dental patients who had not. PJI occurred in 328 patients in the dental group
and 348 in the nondental group. PJI occurred in 13 patients in the antibiotic group and in 12 in the nonantibiotic group. The authors concluded that the risk of PJI is not increased following dental procedures in patients with hip or knee replacement and is unaffected by AP.
A 2022 case-crossover study in the Journal of the American Medical Association (JAMA) looked at nearly 10,000 patients in the UK with late prosthetic joint infection (LPJI) and compared the number of IDPs performed per month in the three months immediately before hospital admission for LPJI with the number of IDPs per month in the preceding 12 months. Patients did not receive AP. There was no correlation between having an IDP and the subsequent development of LPJI.
In January 2023, a case-crossover study published in JADA looked at nearly 2,500 US patients with LPJI and the incidence of IDPs in the three months immediately prior to LPJI development versus the incidence of IDPs in the preceding 12 months, and whether AP had been used.9 The results again showed no correlation between IDPs and development of LPJI, as well as no protective benefit of AP. The last two studies were designed and powered to detect any association between IDPs and LPJI and have nearly 30 times and seven times more LPJI cases than the study by Berbari et al. that informed the ADA CPG and AAOS AUC.
This data is perhaps not surprising since the vast majority of PJIs are caused by Staphylococci. In contrast, oral viridans group streptococci (VGS) are involved in less than 5% of PJI cases. Given that the frequency of VGS bacteremia is higher from routine oral hygiene activities such as toothbrushing than from IDPs (particularly in those with poor oral hygiene), it is more likely that these account for the very small number of LPJI cases caused by VGS. Hence, the best way to reduce the small number of LPJI due to oral bacteria is to focus on improving oral hygiene in those with prosthetic joints (particularly those with poor oral hygiene), rather than using AP. There is mounting evidence that poor oral hygiene, resulting in increased dental plaque, calculus, and caries, may be an associated risk factor for distant site infections caused by oral bacteria.
Considerations regarding infective endocarditis
Although recent data suggests that IDPs are unlikely to be associated with a significant risk of developing LPJI (and hence AP is unlikely to be effective in preventing LPJI), the situation is different with infective endocarditis (IE). Although less than 5% of LPJI are caused by oral bacteria, 35%–45% of IE cases are associated with oral bacteria. Moreover, recent data from the same research group that showed no significant effect of AP in preventing LPJI also showed a significant association between IDP and IE for those at highest risk of IE, and that AP use prior to IDPs for those at highest risk of IE significantly reduced the subsequent risk of IE. However, poor oral hygiene has been shown to be a risk factor for the development of IE and likely accounts for the small number of LPJI caused by oral bacteria.
Antibiotic resistance
You might be thinking that you’ve used AP for prosthetic joint patients for years without problems, so isn’t it reasonable to simply continue to do so? With recent evidence demonstrating no protective benefit of AP prior to IDPs and no association between IDPs and LPJI, we must focus on antibiotic stewardship and the many risks of using antibiotics, including allergy, anaphylaxis, gastrointestinal distress, antimicrobial resistance (AMR), and Clostridioides difficile (C.diff) infection (CDI). An estimated 35,000 deaths occur annually due to antibiotic-resistant infections, and another 29,000 deaths occur annually due to CDI. That equates to a death associated with antibiotic use every 8–10 minutes, and these numbers likely represent a significant underestimate.
Most community-acquired CDIs are associated with antibiotic use, which accounts for over 50% of all CDIs and are outpacing infections acquired in hospitals and physicians’ offices. The top three risk factors associated with CDI are recent hospitalization, recent antibiotic use, and being over age 65—all common factors for most people undergoing joint replacements. The surgery is done in a hospital or outpatient surgery center, the patient receives intraoperative IV antibiotics, and is often age 65 or older. A CDI can occur up to three months after having taken even a single dose of antibiotic, so we may be unaware of patients who develop CDI after our recommendation for AP.
A study by Thornhill et al. showed 13 deaths per million single doses of 600 mg clindamycin used for AP, all due to C. diff or antibiotic-associated colitis. Amoxicillin had the least adverse drug reactions and resulted in no deaths.
Mounting rates of antibiotic resistance among many different bacteria is considered one of the most important global issues in health-care today. A study by Costelloe et al. showed patients developed antibiotic resistance from a therapeutic course of antibiotics for urinary tract infections or skin infections for up to 12 months. The greater the number or duration of antibiotic courses in the previous 12 months, the greater the likelihood of resistant bacteria isolated from antibiotic-exposed patients. In addition, a recent study by Hays et al. has shown a significant increase in MRSA PJIs compared to a decade ago, potentially implicating overutilization of antibiotics as a plausible culprit.
Weighing risks against benefits
Current evidence suggests that the risks associated with giving AP to patients with prosthetic joints outweigh any benefit in reducing the risk of developing LPJI. This contrasts with the situation for IE, where recent evidence suggests that for patients at high IE risk only, the benefits of providing AP for IDPs are likely to outweigh the disadvantages. Although guideline committees in almost every country recommend AP for patients at high risk for IE, this is not the case for patients with prosthetic joints. Orthopedic surgeons and dentists in many countries don’t recommend AP for prosthetic joint patients undergoing IDPs. There is no evidence that the incidence of LPJI is any higher in these countries, which include Australia, Brazil, Canada, Denmark, France, Netherlands, Norway, Portugal, and the United Kingdom.
We hope this article has given you the knowledge and confidence to make an informed decision in favor of eliminating routine AP use for patients with prosthetic joints, and that it leads to practicing evidence-based medicine as we play our part in antibiotic stewardship to reduce the incidence of antimicrobial resistance. As clinicians, it is our responsibility to determine the best care for patients, including the appropriate use of antibiotics. Long-held practice patterns are hard to change, but the most recent evidence should convince us to educate patients who have prosthetic joints about why AP is not only unnecessary but also potentially harmful. This is what practicing evidence-based medicine looks like, not only for individual patients but for all of society.