What is a periprosthetic joint infection

Infection in a joint is a critical condition that needs rapid attention and intervention to minimize damage and assure the best possible outcome. An infection associated with a joint prosthesis, or periprosthetic joint infection (PJI), is a very serious condition with few diagnostic alternatives available to the orthopaedic surgeon prior to surgery.

The Lyfstone calprotectin test for synovial fluid is a novel rapid test solution allowing assessment of the calprotectin level in the synovial fluid as a diagnostic aid for PJI. Use of the test can enable the surgeon to reach a diagnosis prior to surgery.

A rapidly growing million dollar problem

Total joint arthroplasty is considered one of the most successful surgical interventions in the history of medicine.

However, infection of these implants, called periprosthetic joint infection (PJI), remains one of the biggest challenges facing orthopaedics today. PJI can lead to additional surgeries, revision, fusion, amputation, and possibly even death.

In the USA, PJI accounts for 25% of failed knee replacements and 15% of failed hip replacements. There is growing research evidence supporting aggressive prognoses for PJI and subsequently revision surgery growth. It is estimated that the US healthcare system spends more than $1 billion per year treating PJI.

The MSIS 13 definition of PJI

The Musculoskeletal Infection Society (MSIS) put forward the initial consensus guidelines for PJI in 2011, and these were revised in 2013. The revised MSIS-13 criteria reached a strong international consensus, and was thereafter widely adopted. It consists of two major criteria and five minor criteria (see table), where an infection can be diagnosed by the presence of either one of the major criteria, or three out of five minor criteria.

The US Food and Drug Administration (FDA) acknowledge the MSIS-13 as the accepted gold standard for PJI diagnosis, and this widespread clinical adoption led Lyfestone to use MSIS-13 as the reference methodology for sensitivity and specificity claims for our product.

Other important PJI definition and algorithms comprise:

  • ICM-18
  • MSIS-11
  • IDSA