Incidence of postoperative infections requiring reoperation after arthroscopic knee surgery.

Purpose: The purposes of this study were to determine the incidence of infection requiring reoperation after arthroscopic knee surgery during a 6-year period and to compare infection rates across different age groups, genders, geographic regions of the United States, and Current Procedural Terminology (CPT) codes through a retrospective review of a large insurance company database.

Methods: A retrospective review of an insurance company database was performed for all knee arthroscopies performed in the United States from 2004 to 2009. The database was first queried for all knee arthroscopies, and the number of those cases requiring additional surgery for infection within 30 days was determined to calculate the incidence of infection. The incidence was stratified by gender, age group, region within the United States, and CPT code. A separate analysis for procedures using allografts was also performed.

Results: A total of 432,038 arthroscopic surgeries were performed, and the number of infections requiring drainage was 638, for an overall incidence of infection from 2004 to 2009 of 0.15%. Among adults, men were affected almost twice as often as women (P < .001), and among children, boys were affected almost 3 times as often as girls (P < .001). A decreasing incidence was noted in patients 60 years or older between 2004 and 2009 (P = .01). Overall, the incidence did not significantly vary by age, region, or CPT codes that specified the implantation of allograft tissue. Compared with diagnostic arthroscopy, the relative risk of infection was higher for CPT-29889 (posterior cruciate ligament reconstruction).

Conclusions: The incidence of infection requiring reoperation after knee arthroscopy from 2004 to 2009 was 0.15%. The incidence was higher among male patients in both the adult and pediatric populations. The incidence of infection decreased from 2004 to 2009 in patients 60 years or older. Among adult patients, the incidence did not vary by age, by region, or by CPT codes that involved implantation of allografts.

Level Of Evidence: Level IV, cross-sectional study.