Prosthetic joint infections

In their recent study, Erik Lenguerrand and colleagues

focused on an im portant complication of hip arthroplasty. Their meticulous work, in combination with a large database and sufficient follow-up period, identified important modifiable risk factors for prosthetic joint infections. However, we would like to comment on two observations.

Firstly, it is remarkable that 42% of prosthetic joint infections in their cohort were diagnosed as late-onset infections 24 months after implantation, which is particularly high compared with other studies. Huotari and colleagues

found in a large study that late-onset infections constitute only 23% of infections. The high frequencies of late-onset infections in the study of Lenguerrand and colleagues might be because the identification and classification of prosthetic joint infection is at the surgeon’s discretion, which is prone to bias. This method of diagnosis can lead to an underestimation of early prosthetic joint infections, as well as delayed prosthetic joint infections, which are even more difficult to diagnose. This finding emphasises the need for standardised, evidence-based algorithms in the diagnosis of prosthetic joint infections.

Secondly, apparently data for antibiotic prophylaxis were not available from the National Joint Registry; however, selection and dosing of the antibiotic agent and timing of antibiotic prophylaxis have been described as essential modifiable risk factors for the prevention of surgical site infections in joint arthroplasty.

Improper (ie, underdosed) antibiotic prophylaxis might also have contributed to the finding that patients with a greater body-mass index have a higher risk for developing prosthetic joint infections.

It should therefore be considered whether data for antibiotic prophylaxis could be included as additional information in the National Joint Registry.