Prosthetic Joint Infections and the Impact of Syndromic Testing

Prosthetic joint infections (PJI) are a significant clinical burden facing patients, orthopedic surgeons, and the entire global healthcare industry. While a small percentage of joint arthroplasty patients end up actually experiencing infection, these occurrences can be dangerous and may involve replacing the prosthesis.¹ Obtaining accurate diagnoses and making informed treatment decisions, all within an actionable timeframe, can improve patient management and even save lives.

The number of patients projected to undergo hip and knee replacements, as well as other joint replacement procedures, is growing.^1–4 Along with that growth is an increasing demand for new and improved clinical tools. The new BIOFIRE ^® Joint Infection (JI) Panel is a fast, accurate, and comprehensive diagnostic solution for joint infections, including PJIs.

What is a Prosthetic Joint Infection?

Of the hundreds of thousands of joint replacement surgeries that are performed each year in the United States, up to 2% of them could result in infection.² PJIs are associated with high morbidity and mortality rates, and they can take a heavy financial toll on individual patients and healthcare systems.²

A PJI occurs when an infection involves an artificial joint that has been surgically implanted. Symptoms of infection typically include fever and chills; pain, redness, and drainage at the surgical incision site; swelling of the joint; and unexpected pain or stiffness in the joint area after recovery from the initial procedure. Any joint that has been surgically replaced—most commonly hips and knees, but also shoulders, elbows, wrists, and ankles—can be affected by a prosthetic joint infection.

How Does a Prosthetic Joint Infection Occur?

A prosthetic joint infection is a serious complication following joint arthroplasty and can present itself years after the procedure. Many PJIs are bacterial and occur when a microorganism is introduced to the infection site during surgery or subsequent procedures. However, the microorganism that causes the PJI may be already present in the body, awaiting an opportunity to cause infection. The internal and external trauma caused by major surgery, as well as the addition of a new prosthesis to the body, create ideal conditions for an opportunistic microorganism.

A PJI can damage or destroy a prosthetic joint, sometimes requiring a second replacement surgery and increasing the risk of further infection and other complications. People with certain pre-existing conditions are more likely to develop a prosthetic joint infection. Common risk factors include diabetes, rheumatoid arthritis, obesity, smoking, the presence of tumors, active infection in the body at the time of surgery, and an otherwise weakened immune system. Prolonged recovery in a communal setting can also increase the risk of infection.

Diagnosing Prosthetic Joint Infections

A joint infection diagnosis relies on several criteria and involves clinical evaluation and several diagnostic tests such as blood culture, synovial fluid testing, radiology, histology, and others. Healthcare providers typically begin with a physical exam of the surgical site and a review of symptoms. Synovial fluid will be collected from the joint for Gram stain and possible culture testing or other procedures.

Available standard-of-care culture options may lack sensitivity, and often fail to provide a result in an actionable timeframe. In fact, traditional culture fails to identify an infecting organism in up to 35% of PJI cases.²

Syndromic Testing for Prosthetic Joint Infections

bioMérieux is the leader in the syndromic approach to infectious disease diagnostics. Unlike many standard-of-care options, syndromic testing uses multiplex PCR technology, which helps make the process faster, more accurate, and more comprehensive than many existing joint infection culture tests.

Our latest syndromic testing solution is the BIOFIRE JI Panel. This new joint infection test takes just one small sample of synovial fluid and about an hour to deliver accurate results on 39 clinically relevant targets. The BIOFIRE JI Panel can detect 31 organisms commonly associated with PJIs—including Gram-positive bacteria, Gram-negative bacteria, and yeast. Additionally, this syndromic test detects eight antimicrobial resistance genes, which aids in the optimization of targeted therapy.

Rapid and actionable answers from the BIOFIRE JI Panel may help guide treatment decisions, including potential antimicrobial therapy and surgical decisions.

Learn More About Prosthetic Joint Infections and Syndromic Testing

In addition to prosthetic infection diagnostics, the BIOFIRE JI Panel can aid in the diagnosis of septic arthritis in native joints.
The rapid PCR BIOFIRE ^® FILMARRAY ^® System targets joint infections and five other common syndromes: respiratory, gastrointestinal, and bloodstream infections, as well as meningitis/encephalitis and pneumonia.

References:

Roerdink RL, et al. The difference between native septic arthritis and prosthetic joint infections: A review of literature. J. Orthop. Surg. 2019,27(2):230949901986046.
Tande JT, Patel R, Clin Microbiol Rev. 2014 Apr; 27(2): 302–345.
Lenguerrand E, et al. Description of the rates, trends and surgical burden associated with revision for prosthetic joint infection following primary and revision knee replacements in England and Wales: an analysis of the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man. BMJ Open. 2017;7(7):e014056.
Premkumar A, et al. Projected Economic Burden of Periprosthetic Joint Infection of the Hip and Knee in the United States. J Arthroplasty. 2021;36(5):1484-1489.e3.