The rate of prosthetic joint infection is underestimated in the arthroplasty registers

In the present issue of Acta Orthopaedica, 2 studies have contributed results on different aspects of the rate of prosthetic joint infection (PJI). The studies have in common that they combined different patient registries, i.e. different data sources, to identify patients who had been reoperated due to PJI. In a study from Finland by Kaisa Huotari et al., the authors’ rationale for this approach was that incidence studies solely based on the Finnish Arthroplasty Register (FAR) had a tendency to underestimate the number of PJIs (Jämsen et al. 2009, Huotari et al. 2010). Thus, the authors combined data from FAR with data from the (Finnish) Hospital Discharge Register to study the rate of late PJI.

The other study on PJI presented in this issue of Acta is from Denmark, by Per Hviid Gundtoft et al. The aim of that study was to estimate “the true incidence of surgically treated deep prosthetic joint infection”. By combining several data sources, including data on microbiology and blood tests, the authors have concluded that 40% of surgically treated PJIs were not reported to the Danish Hip Arthroplasty Register (DHR).