Protracted Outbreak of Postarthroscopy Infections Associated with Flash Sterilization of Instruments

Background:   Infections following arthroscopic knee surgeries are rare.  In June 2007 an increased number of postarthroscopy surgical site infections (SSIs) was reported at a community hospital (Facility A). 

Objective: To identify and correct factors involved in the outbreak of postarthroscopy SSIs.

Methods:   The case definition was septic arthritis requiring surgical washout and intravenous antibiotic within 30 days after arthroscopic procedure.  Cases were identified by review of the SSI database.  Infection control personnel interviewed operating room (OR) staff and observed OR practices related to arthroscopic procedure.

Results:   16 infections following arthroscopy were identified between Jan 1, 2006 and October 10, 2007, with 14 cases meeting the case definition.  Seven different organisms were isolated with methicillin-susceptible Staphylococcus aureus being the most frequent organism.  All but one infection was attributed to a single surgeon (Surgeon A).  Surgeon A performed 552 arthroscopic procedures with 13 (2.4%) SSIs.  In contrast, 1662 arthroscopic procedures were performed at Facility A by 8 other surgeons with one SSI (0.06%).  The relative risk (RR) of developing SSI following arthroscopy performed by Surgeon A compared to other surgeons was 40.0, p<0.0001.  Surgeon A performed 848 arthroscopic surgeries at an academic institution (Facility B) from 2001 – 2005, with SSIs occurring in 3 patients (0.3%).  The RR of post-arthroscopy SSI occurring when Surgeon A performed arthroscopy at Facility A compared to Facility B was 6.7, p=0.001.   At Facility A arthroscopes were cleaned in the OR suite and sterilized using flash steam sterilization between procedures.  The arthroscope, surgical instruments and other supplies were placed in a single tray for sterilization, which was performed by surgical technicians who had not been trained in disinfection and sterilization procedures.  No other surgeon at Facility A used flash sterilization to sterilize arthroscopes.  Flash sterilization was not used at Facility B, where arthroscopes were decontaminated, cleaned and sterilized in the central processing area and transported to the OR in a sterile package.  Following the investigation, several corrective actions were taken.  Additional arthroscopes were purchased, flash sterilization was discontinued and all arthroscopes were processed in central processing by trained personnel.  SSIs returned to baseline at Facility A. 

Conclusions:   We report a protracted outbreak of postarthroscopy SSIs associated with routine use of flash sterilization.  Epidemiologic investigation implicated Surgeon A when operating at Facility A.  Review of operating room procedures pointed to flash sterilization as the cause whereas review of performance-based measures led to the premature conclusion that Surgeon A was the source of the outbreak.  Flash sterilization is not an appropriate method for routine sterilization.