Finegoldia magna: An Infrequent Guest in Orthopedic Infections

Background: Finegoldia magna is a species of anaerobic gram-positive coccus considered part of human microbiota. It has been described as a cause of skin and soft tissue infections, but it is not a common cause of operation-related infections. Objectives: Describe the characteristics, treatment, and results of musculoskeletal infection by F. magna treated in our center. Methods: We performed a descriptive, retrospective observational study. Clinical records of all musculoskeletal surgical infections treated in our department between 2012 and 2022 were reviewed. We selected the patients with a positive culture for F. magna. Risk factors for infection, patient's medical records, previous operation performed, time from surgical procedure to infection, susceptibility tests, antibiotic and surgical treatment for the infection, and recovery rate were registered for the analysis. Results: Twenty patients have positive cultures for F. magna, representing 15.5% of the anaerobic infections. Eleven of them were arthroplasties, three fracture synthesis, two foot operations, two spinal operations, and two soft tissue operations. All patients underwent operation and antibiotic treatment. The most commonly used antibiotic scheme was amoxicillin followed by amoxicillin-rifampicin. Eighty percent of the patients achieved a complete clinical recovery with a mean of 2.1 surgical procedures. Patients with polymicrobial infections required twice the number of operations (p = 0.047) and exhibited a failure rate of 36% compared with 0% for monomicrobial cases (p = 0.043). Conclusions: Orthopedic infections caused by F. magna are infrequent, but they usually have good outcomes. Polymicrobial infection with F. magna exhibits poorer clinical results and requires a greater number of operations compared with monomicrobial ones.