Multi-institutional observational study on the relationship between oral infection focus and surgical site infection in artificial arthroplasty and the clinical significance of tooth extraction: An analysis using propensity score matching

Background/purpose: Surgical site infection (SSI) is a serious complication of artificial arthroplasty. Its relationship with dental infections and the necessity of preoperative dental screening remains debated. This study examined the relationship between oral condition and risk of SSI, along with preoperative tooth extraction effect, in patients undergoing artificial arthroplasty. Materials and methods: Patients undergoing artificial hip or knee arthroplasty between April 2018 and September 2021 were retrospectively examined for age, sex, surgical site, surgical procedure, surgical time, preoperative hemoglobin level, white blood cell count, albumin level, creatinine level, remaining teeth, apical lesions ≥3 mm, periodontal pockets ≥4 mm, root fractures, residual roots, local infection symptoms in the oral cavity, preoperative or postoperative tooth extraction, and SSI occurrence. Tooth extraction effects on SSI incidence were analyzed using propensity score matching. Results: The study included 3950 patients from 30 facilities. SSI occurred in 79 patients (2.0 %). Multivariate analysis identified surgery time and oral infection symptoms as significant risk factors. SSI occurred in 75 of 3793 patients without preoperative tooth extraction (2.0 %) and in 4 of 157 patients with tooth extraction (2.6 %), with no significant difference. However, in 292 propensity-matched patients, SSI incidences were 2.7 % and 6.2 % with and without preoperative extraction, respectively, indicating that preoperative infectious tooth removal may reduce SSI risk. Conversely, SSI occurred in three of seven patients (42.9 %) with tooth extraction within 60 days post-surgery, highlighting its risks. Conclusion: Oral infections increase SSI risk after artificial arthroplasty. Preoperative tooth extraction is recommended to reduce this risk.