Abstract
Aim
The risk of haematogenic periprosthetic joint infection (PJI) after dental procedures is discussed controversially. To our knowledge, no study has evaluated infections according to the origin of infection based on the natural habitat of the bacteria. We investigated the frequency of positive monomicrobial cultures involving bacteria from oral cavity in patients with suspected PJI compared to bone and joint infections without joint prosthesis.
Method
In this retrospective study we included all patients with suspected PJI or bone and joint infection without endoprosthesis, hospitalized at our orthopaedic clinic from January 2009 through March 2014. Excluded were patients with superficial surgical site infections or missing data. Demographic, clinical and microbiological data were collected using a standardized case report form. Groups were compared regarding infections caused by oral bacteria. χ2 test or Fisher's exact test was employed for categorical variables and t-test for continuous variables.
Results
A total of 1673 patients were included, of whom 996 (60%) had a suspected PJI and 677 (40%) an osteoarticular infection without joint endoprosthesis (control group). In patients with suspected PJI the median age (standard deviation) was 67 (14) years; 407 (41%) were males. The anatomic location of the prosthesis was hip in 522 (52%) patients, knee in 437 (44%), megaprostheses in 14 (1%), shoulder in 8 (1%) and other endoprosthesis in 15 (2%) patients. In 437 (44%) of PJI cases pathogen(s) were detected, 271 (62%) were monomicrobial and 166 (38%) polymicrobial. Of 996 patients with suspected PJI, 2.4% (n = 24) had monomicrobial infections caused by bacteria belonging to the normal oral flora, predominantly oral streptococci (n = 21). In contrast, only 0.4% (n =3) of the control group without joint prosthesis had monomicrobial infections caused by oral bacteria. This difference was statistically significant (p = 0.002), whereas the patient age (p = 0.058) and the anatomic location of the joint prosthesis (p = 0.622) did not have any effect on the infections due to oral bacteria.
Conclusions
The incidence of infections caused by oral bacteria was significantly higher in patients with endoprosthesis than in other osteoarticular infections (2.4% versus 0.4%). This finding indicates that joint prostheses are at risk of haematogenous PJI originating from oral cavity. Future prospective studies need to determine the exact risk of haematogenic PJI caused by oral bacteria, as well as the potential of preventing these infections by antibiotic prophylaxis.
