Capnocytophaga canimorsus Periprosthetic Joint Infection in an Immunocompetent Patient: A Case Report

INTRODUCTION: A periprosthetic joint infection (PJI) is a potentially devastating complication following an arthroplasty procedure. There are many organisms that commonly cause this complication; in this case report, we will discuss a PJI caused by an unusual bacteria found in the mouths of domestic pets. OBJECTIVE: To present a case report of a patient with a periprosthetic hip infection from Capnocytophaga canimorsus and review the literature. METHODS: We present a case of C canimorsus PJI in an immunocompetent woman who had undergone a total hip arthroplasty. The patient was doing well postoperatively for many years until she was bitten on the foot by a domestic canine. Patient diagnosed using Musculoskeletal Infection Society criteria, then treated with explant of the hip prosthesis, irrigation and debridement, placement of an antibiotic cement spacer, and a 6-week course of intravenous antibiotics. RESULTS: Unfortunately, while awaiting replant, this patient had a massive myocardial infarction and died. DISCUSSION: Current literature suggests treating canine bites with amoxicillinas well as a discussion with patients pre-/postoperatively from a lower extremity arthroplasty specialist. CONCLUSION: Capnocytophaga canimorsus is a rare cause of infection, even more unusual in an immunocompetent patient. This study highlights the importance of considering C canimorsus as a cause of PJI, regardless of the immunologic status of the patient.