New research from the Rothman Orthopaedic Institute in Philadelphia examines whether organisms which cause periprosthetic joint infections (PJI) have changed.
The authors retrospectively reviewed the medical records of 1,214 patients with PJI treated at the Rothman Orthopaedic Institute between 2000 and 2017; the study included 501 total hip arthroplasties (THA) and 713 total hip arthroplasties (THA).
Patient demographics, culture findings, number of positive cultures, index joint, and date of surgery were collected. Organisms were differentiated using culture or confirmed by Matrix Assisted Laser Desorption Ionization-time of flight mass spectrometry. A diagnosis of periprosthetic joint infections was established using the Musculoskeletal Infection Society criteria.
According to the study authors, “There was a higher incidence of Streptococcus species and culture negative species identified in periprosthetic joint infections in knees versus hips. On the other hand, there were more Staphylococcus aureus, resistant species, Gram positive, Enterococcus, Pseudomonas in hips than knees.”
Co-author Javad Parvizi, M.D., vice chairman of research at Thomas Jefferson University Hospital and director of clinical research at the Rothman Orthopaedic Institute, summarized the results of this study to OTW, “We found that any microorganisms can cause infection of the joint and/or prosthesis…and the organisms profile seems to be changing.”
Asked about his thoughts on previous work regarding biofilm production, early hematogenous spread, and high virulence, Dr. Parvizi said, “Organisms with high virulence are able to cause serious infections that can causes systemic issues. The mode of spread of these organisms in the body to the site of a prosthesis is unknown but likely to involve hematogenous spread as well as other modes.”
