Septic Failure After One-Stage Exchange for Prosthetic Joint Infection of the Hip: Microbiological Implications.

BACKGROUND

The microbiological implications of septic failure after 1-stage exchange for prosthetic joint infection (PJI) of the hip remain unclear.

METHODS

Information was gathered on comorbidities, previous procedures, preoperative and postoperative microbiology results, methods of detection, and antibiotic resistance patterns, for all patients, who developed septic failure after 1-stage exchange for PJI of the hip performed at our institution during 2001-2017.

RESULTS

Seventy-seven patients were identified. Septic failure was diagnosed a mean of 1.7 (standard deviation 2.3, range 0-11.8) years later. Although the spectrum of microorganisms was similar to preoperative, in the majority of patients (55%), the initial microorganism(s) was (were) replaced by (a) totally different microorganism(s). Overall, there was a decrease in the number of polymicrobial PJIs. The number of patients with high virulent microorganisms decreased significantly from 52 to 36 (P = .034). The number of PJIs due to gram-negative pathogens remained similar (11 vs 14, P = .491). The number of rifampicin-resistant staphylococci, fluoroquinolone-resistant streptococci, enterococci, and fungi changed from 8 to 15, 0 to 2, 7 to 3, and 1 to 2, respectively, but these changes did not reach statistical significance.

CONCLUSION

The majority of reinfections is caused by different infecting bacteria, hence it is essential to perform a new diagnostic workup and not base treatment decisions (solely) on historical cultures. We were furthermore unable to irrefutably prove that, from a microbiological point of view, septic failure after 1-stage exchange comes with increased challenges. Given the time interval to failure, we propose that a longer follow-up of these patients is needed, than previously suggested.