Oral Bacteremia as a Cause of Prosthesis Failure in Patients With Joint Replacements

Over a million total joint replacements, mostly hip and knee, are performed each year in the United States alone. With many patients living for decades after these procedures, it is fair to state that about 10 times that number of patients have these devices in place and that every oral and maxillofacial surgeon will frequently see patients with joint prostheses. Additionally, tens of millions of dental visits each year in the US will be by patients with joint prostheses.

Joint prostheses also fail with an annual finite risk of several percent that has changed little since devices have improved with total arthroplasty, and with more biocompatible, durable materials. Still, failure of joint prostheses occurs due to mechanical loading, osteoporotic fracture, alloplast particulation, foreign body reaction, and infection.

Loss of a total joint replacement is a serious, potentially devastating outcome and its prevention needs to be paramount. One of the principle means of preventing failure of total joint arthroplasty is to prevent bacterial infection of the prosthesis. While colonization at the time of surgery with Staphylococcus aureus, Staphylococcus epidermidis, gram-negative rods, and Enterococcus remains the primary source of infection (all are gastrointestinal or cutaneous organisms), rarely, oral organisms such as Streptococcus sanguis, transported via hematogenous spread, have been identified in failed joint prosthesis in patients with advanced periodontal disease1 or temporally associated with dental interventions.

Despite their rarity, these oral-sourced infections have produced an outsized interest among orthopedists and dentists. In 2009, the American Academy of Orthopedic Surgeons (AAOS) produced its Information Statement on Antibiotic Prophylaxis for Bacteremia in Patients With Joint Replacement.2 The major change in their recommendation is to make it more rigorous in that instead of 2 years of prophylaxis they now recommend lifetime prophylaxis during bacteremia-causing procedures such as dental care. Following this statement, the American Dental Association (ADA) reviewed its recommendations for antibiotic prophylaxis in patients with total joint replacement on the ADA Web site.3 In that communication they state that “dental extractions, periodontal procedures, including surgery, subgingival placement of antibiotic fibers/strips, scaling and root planning, probing, recall maintenance; dental implant placement and replantation of avulsed teeth; endodontic (root canal) instrumentation or surgery only beyond the apex, intraosseous local anesthetic injections, prophylactic cleaning of teeth or implants where bleeding is anticipated” are criteria to perform antibiotic prophylaxis. These procedures encompass the great majority of all routine dental visits.

These recommendations, if implemented, will cause hundreds of millions of doses of antibiotics to be taken in patients over the coming years to prevent a rare event, the contamination of a joint prosthesis with an oral organism. Additionally, this phenomenon must be rare since it is only identifiable in very sporadic case reports over a 30-year period. A paper by Bartzokas et al1 produces 4 cases among an unknown population of patients, and the AAOS position paper relies on a 1976 article by Rubin in which just 3 patients with gram positive infection of the total hip were temporally associated with patient care.

Based upon this level of anecdotal information, the risk that a dental intervention will infect a joint prosthesis cannot be quantified or compared to the risk of prophylaxis. Several known risks of antibiotic prophylaxis include:

If the goal is prevention of infected joint replacements, then where is the recommendation to optimize oral health prior to total joint replacement? Only a very small portion of bacteremia from an oral source is associated with dental treatment. Nearly all bacteremia is associated with active caries and periodontal disease. Except for femoral neck fracture there are very few emergency indications for joint replacement as most patients have suffered from degenerative joint disease for some time. Yet it is rare to see a surgeon or rheumatologist concerned over the effects of poor oral health on the health of their patients' joints prior to joint replacement or to express concern over poor oral health in their patients with joint replacement. The most important bacteremias from the mouth do not occur in the dental office. They are the daily bacteremias and production of cytokines with resulting systemic tissue injury that result from untreated caries and periodontal disease. While having the conversation on antibiotic prophylaxis, ask your bone and joint colleagues (in a perhaps productive and not teasing way) if they would now advise their other total joint patients of the importance of good oral health measures, promoting prevention and treatment of active dental diseases.

Recommending that millions of patients be medicated at enormous cost should not depend upon a few case reports. Randomized clinical trials (RCTs) of optimized oral health versus no specific intervention should be done for patients with total joints. RCTs regarding routine antibiotic prophylaxis according to these now existing ADA and ASOS recommendations are also needed before assessing the utility of their recommendations. It is entirely possible that such RCTs would demonstrate a negative value of various interventions including antibiotic prophylaxis currently being promulgated. Until clinical scientific evidence is available, the reader should note that the ASOS paper is kindly subtitled: “An educational tool based on the opinion of the authors.” That leaves oral and maxillofacial surgeons free to form their own opinions and to act based upon the levels of evidence available, and in the best interests of their patients.