Rethinking antibiotic prophylaxis
for patients with prosthetic joints
by Dr. Thomas Paumier
With nearly 1 million prosthetic
knee and hip replacements done
yearly, and more than 4 million
estimated to be done yearly
by 2030,1 it’s likely that every day a patient
with prosthetic joints presents in a practice
requiring an invasive dental procedure. That,
in turn, means dentists must decide whether
antibiotic prophylaxis (AP) is necessary for
these patients before treatment.
There is still confusion among dentists
and orthopedic surgeons about whether to
use AP, even though the current guidelines
have been in place at least five years. That
confusion is understandable, considering
there have been six different information
statements or guidelines from the American
Dental Association (ADA) and the American
Academy of Orthopedic Surgeons (AAOS)
in the past 25 years.
The most recent ADA clinical practice
guideline (CPG), published in JADA in
2015, states: “In general, for patients with
prosthetic joint implants, prophylactic
antibiotics are not recommended before
dental procedures to prevent prosthetic
joint infection.”2
And in 2017, the AAOS released an
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
has all of the following co-morbidities:
immunocompromised, diabetic and having
previous joint infections. The AUC states:
“[I]t 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.”3
So, why have we used AP for patients
with prosthetic joints? Knowing that invasive
dental procedures cause bacteremia, which
can potentially lead to distant site infections,
and that we have used AP for patients
with prosthetic heart valves or a history of
infective endocarditis, it seemed reasonable
that AP would be appropriate for patients
with prosthetic joint replacements. However,
studies show there is no association between
dental procedures and prosthetic joint
infections (PJIs). And there is evidence that
antibiotics provided before oral care do not
prevent prosthetic joint infections.4,5
Additionally, there is the potential for
significant harms from taking antibiotics.
It is estimated that 1%–2% of joint arthroplasties
will develop a PJI, usually within
two years. Those occurring within three
months are considered early infections and
likely occurred at the time of surgery; late
infections occur after three months and are
attributed to hematogenous spread.
However, many infections occurring in
the first year could be smoldering infections
from the time of surgery. The vast majority
of PJI are caused by staphylococcal bacteria,
with viridans (oral) streptococci involved
in less than 5% of cases.5 In a study by
Swan, when a late PJI was associated with
a preceding sentinel event, it was always
related to a dermatologic infection or cellulitis
resulting in hematogenous spread, and caused
by staph bacteria.6
Transient bacteremia occurs with most
dental procedures and with routine daily
activities, including chewing, brushing and
flossing. It lasts, on average, from six to 60
minutes per episode, and it is estimated
that bacteremia from normal daily activities
amounts to 90 hours per month.7 So, if oral bacteria are involved with PJI, it is much
more likely to result from chronic bacteremia
rather than an isolated dental procedure.
If AP is necessary before dental procedures,
why is it not necessary before eating or
brushing and flossing teeth?
Antibiotics’ benefits
and risks
What happens when we take antibiotics
before a dental procedure, and does this
prevent distant site infections? Antibiotics
taken before dental procedures reduce but do
not eliminate bacteria from the bloodstream,
and decreased bacteremia does not necessarily
mean prevention of distant site infections.
Many PJIs occur in patients who have taken
AP before dental procedures.
A study by Dios showed that taking 2g of
amoxicillin before extraction reduced bacteremia
by approximately 50%. Clindamycin
was ineffective at reducing bacteremia before
extraction and is the equivalent of having
not taken an antibiotic.8 Clindamycin should
never be used for antibiotic prophylaxis, even
when AP is indicated (recommended cardiac
conditions). Keflex 2g is recommended for
patients who are allergic to amoxicillin and
have not had an anaphylactic reaction, severe
skin reaction or angiodema. Azithromycin
500mg or clarithromycin 500mg are indicated
for true amoxicillin-allergic patients.
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? The answer is
no: There is minimal if any benefit from
using AP, and there are many risks to using
antibiotics, including anaphylaxis, gastrointestinal
distress, antibiotic resistance and
Clostridioides difficile (C. diff) infection.9
An estimated 35,000 deaths occur yearly
because of antibiotic-resistant infections,
and another 29,000 deaths occur yearly
from C. diff infections.10
Community-acquired C. diff infections
are outpacing infections acquired in
hospitals and physician offices, and most
are associated with antibiotic use. The top
three risk factors for C. diff infection are
recent hospitalization, recent antibiotic use
and being over age 65—something almost
all patients undergoing joint replacements
have in common. The surgery is done in a
hospital or outpatient surgery center, they
receive intraoperative IV antibiotics and
often are over age 65.
A C. diff infection can occur up to six
weeks after having taken an antibiotic, so
we may be unaware of patients who develop
C. diff infections after our recommendation
for AP. A study by Thornhill et al. showed
13 deaths per 1 million single doses of 600mg
clindamycin used for AP, all from C. diff- or
antibiotic-associated colitis. Amoxicillin
had the least adverse drug reactions and
resulted in no deaths.11
But that is today; clindamycin was
not associated with as many adverse drug
reactions decades ago. Will amoxicillin be
associated with more adverse drug reactions
and death in the future? A study by Costelloe
showed patients developed antibiotic
resistance from a therapeutic course of
antibiotics for UTI 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 that patient.12
So while we think of antibiotic resistance
as a global problem only, it’s a problem at
an individual level as well.
Conflicting opinions
confuse patients
Unfortunately, many orthopedic surgeons
still recommend AP for life, using
outdated prescribing regimens and not
following the current guidelines. Additionally
many surgeons advise patients that they should not have dental treatment for three
months after their arthroplasty … to which
I ask patients if their surgeon also told them
they shouldn’t brush or floss their teeth for
three months, because those activities induce
a bacteremia similar to that of a dental
procedure. I also ask if their surgeon inquired
about their oral health and the last time
they saw a dentist before they had surgery.
The highest risk of infection is at the time
of surgery, yet in my experience orthopedic
surgeons seldom ask patients if they have
existing dental problems before surgery.
There’s no need to delay any dental
treatment after joint replacement, but conflicting
recommendations from the surgeon
and dentist put patients in an awkward
situation: They essentially have to decide
for themselves whether to use AP or delay
dental care.
Orthopedic surgeons and dentists in
many other countries don’t recommend
AP for patients undergoing invasive dental
procedures, and there is no evidence that
late PJI incidence is any higher in those
countries, which include Australia, Brazil,
Canada, Denmark, France, Netherlands,
Norway, Portugal and the United Kingdom.
I hope this article has given you the
knowledge and confidence to make an
informed decision about (not) using AP for
patients with prosthetic joints. It would be
the rare situation where I would consider
using AP for a patient with a prosthetic
joint; I haven’t recommended or written
a prescription for AP for a patient with a
prosthetic joint in more than 10 years.
If an orthopedic surgeon recommends
AP and the patient prefers to use it, I ask
the patient to have the surgeon prescribe it,
because if you write the prescription at the
recommendation of the surgeon, you are the
one liable for any adverse events related to
the antibiotic use.
As a practical matter, if a patient prefers
to use AP and forgot to take it, I will give
them amoxicillin or azithromycin at the
time of the appointment, advising them of
the risks of antibiotic use and that there is
no evidence of benefit. Medico-legally, there
is no defense if you have given AP without
proper informed consent and the patient ends
up in the hospital from a C. diff infection.
If you treat a patient without using AP and
they develop a PJI caused by viridans strep,
there is no way to determine if it occurred
as a result of bacteremia from normal daily
activities or the dental procedure. You may
still be sued, but the science would be in
your favor.
It is our responsibility as dentists to
determine the best care for the patients we
treat, including whether AP is appropriate.
Long-held practices are hard to change,
but taking the time to educate patients
who have a prosthetic joint about why AP
is not necessary is worthwhile. It may just
save their life. And it will ensure you are
practicing to the standard of care.
Reference
1. Kremers, H.M., Larson, D., et al. “Prevalence of Total Hip
and Knee Replacement in the United States.” J Bone Joint
Surg Am. 2015 Sep 2; 97(17):1386–1397.
2. Sollecito, T.P., Abt, E.,, Lockhart, P.B., Truelove, E.,
Paumier, T.M., et al. “The Use of Prophylactic Antibiotics
Prior to Dental Procedures in Patients with Prosthetic Joints:
Evidence-Based Clinical Practice Guideline for Dental
Practitioners—A Report of the ADA Council of Scientific
Affairs.” JADA 2015; (1):11–16.
3. http://www.orthoguidelines.org/go/auc.
4. Berbari, E.F., Osman, D.R., Carr, A., et al. “Dental Procedures
As Risk Factors for Prosthetic Hip or Knee Infection: A
Hospital-Based Prospective Case-Control Study.” Clin Infect
Dis. 2010; 50(1):8–16.
5. Thornhill, M.H., Crum, A., Rex, S., Stone, T., Campbell,
R., Bradburn, M., Fibisan, V., Lockhart, P., Springer, B.,
Baddour, L., and Nicholl, J. “Analysis of Prosthetic Joint
Infections Following Invasive Dental Procedures in England.”
JAMA Network Open. 2022; 5(1):e2142987.
6. Swan, J., Dowsey, M., Babazadeh, S., Mandaleson, A., and
Choong, P.F. “Significance of Sentinel Infective Events in
Haematogenous Prosthetic Knee Infections.” ANZ J Surg.
2011; 81(1- 2):40–45.
7. Guntheroth, W.G. “How Important Are Dental Procedures
As a Cause of Infective Endocarditis?” Am J Cardiol 1984;
54:797–801.
8. Dios, P.D., Carmens, I.T., et al. “Comparative Efficacies of
Amoxicillin, Clindamycin and Moxifloxacin in Prevention
of Bacteremia Following Dental Extractions.” Antimicrob
Agents Chemother. 2006 Sep; 50(9): 2996–3002.
9. Thornhill, M.H., Dayer, M.J., Durkin, M.J., Lockhart,
P.B., and Baddour, L.M. “Risk of Adverse Reactions to
Oral Antibiotics Prescribed by Dentists.” J Dent Res. 2019;
98(10):1081–7.
10. CDC’s 2019 Antibiotic Resistance Threats Report.
11. Thornhill, M.H., Dayer, M.J., Prendergast, B., Baddour,
L.M., Jones, S., and Lockhart, P.B. “Incidence and Nature
of Adverse Reactions to Antibiotics Used As Endocarditis
Prophylaxis.” J Antimicrob Chemotherapy, April 2015.
12. Costelloe, C., Metcalfe, C., Lovering, A., Mant, D., and
Hay, A.D. “Effect of Antibiotic Prescribing in Primary Care
on Antimicrobial Resistance in Individual Patients: Systematic
Review and Meta-Analysis.” BMJ 2010; 340:c2096.
Dr. Thomas Paumier, a cum laude graduate of The Ohio State University College
of Dentistry, completed a general practice residency at St. Elizabeth Medical
Center in Youngstown, Ohio. He has been in private practice since 1988 in Canton,
Ohio, where he also is on the faculty of the Cleveland Clinic Mercy Hospital GPR.
Paumier was a member of the American Dental Association and American
Academy of Orthopedic Surgeons expert panels that wrote the clinical practice
guidelines and appropriate use criteria for antibiotic prophylaxis for prosthetic
joint patients. He also co-authored the ADA Clinical Practice Guideline for Appropriate Antibiotic Use
for Odontogenic Infections and was the 2019 recipient of the ADA Evidence-Based Dentistry Clinical
Practice Award. He is a fellow in the International and American College of Dentists and a past president
of the Ohio Dental Association.