Javad Parvizi, MD, FRCS

GRAPEVINE, Texas — In this video, Javad Parvizi, MD, president of the American Association of Hip and Knee Surgeons, recaps and discusses the AAHKS Annual Meeting, which took place Nov. 2 to 5.

Published results showed blood microbial cell-free DNA sequencing may accurately identify pathogens and be used to monitor infection clearance during the treatment period among patients with periprosthetic joint infections.

It has been 5 years since the first International Consensus Meeting on Periprosthetic Joint Infection was held. That meeting, held in Philadelphia, was lauded as a success and was attended by 400 delegates from 52 countries. The proceedings of the meeting were published in the peer-reviewed Journal of Arthroplasty and in a book translated into 18 languages that came out after the meeting. More than 30,000 copies of the book were distributed worldwide. The definition of periprosthetic joint infection proposed by the International Consensus Meeting group was adopted by the CDC.

Pathogen identification remains a challenge and culture methods have limitations. Novel molecular methods have become clinically available. Matrix-assisted laser desorption ionization-time of flight mass spectrometry — MALDI-TOF — is a new technology for rapid and cost-effective identification of microorganisms, including those implicated in periprosthetic joint infection. Current methods for identification of pathogens rely upon costly and time-consuming culture techniques. MALDI-TOF exploits the proteome of microorganisms for pathogen recognition. It is efficient for implementation at the large institution-level and can precisely classify microorganisms down to the strain.

Management of periprosthetic joint infection is challenging on many accounts. Fungal periprosthetic joint infections are particularly difficult to treat. The problem is the incidence of fungal infections has increased globally in the last few decades. Fungal periprosthetic infections, although rare, are similarly increasing in prevalence. Most case series of patients with fungal periprosthetic joint infections report a disastrous outcome for surgical management of these patients with treatment failure rates of up to 50% at 2-year follow-up. Part of the problem relates to the complex biofilm that fungi can form. Furthermore, patients with fungal periprosthetic joint infection are often immunocompromised with impaired cellular immunity.

Since Nobel Laureates J. Robin Warren, AC, and Barry J. Marshall, AC, FRACP, FRS, FAA, DSc, implicated Helicobacter pylori as a causative agent in the pathogenesis of peptic ulcer disease, infection has been proposed as the root cause of multiple disease processes. In recent years, the collection of all the microorganisms living in association with the human body, otherwise known as the microbiome, has gained much attention. Attention to this topic peaked when the White House announced the $121-million National Microbiome Initiative.

As Desiderius Erasmus stated in the 15th century, prevention is better than cure. As the orthopedic community braces itself to deal with the increased burden of infection, prevention of surgical site infection and periprosthetic joint infection has moved into center stage.

In 1881, Robert Koch, MD, was credited for being the first person to develop the method for isolating infecting organisms using the culture medium. Since then, microbiologic culture has been the “gold standard” for the identification of infecting organisms. This development marked a revolution in microbiological methods and has been the cornerstone of isolating the infecting organism and implementing the appropriate antimicrobial treatment in many specialties in medicine. Interestingly, the method of culture described by Koch has undergone little change during the last 2 centuries.

H.W. Buchholz, MD, is credited as the first clinician to add antibiotics to polymethylmethacrylate cement. He thought the antibiotic would elute from cement and accumulate in the local environment of the joint.

Infection is a challenging and dreaded complication of any surgical procedure, particularly so in orthopedic surgery. Infection may be caused by a variety of organisms, and convention dictates isolation of a pathogen from a culture should not be considered representative of infection unless the organism is a “true” pathogen.