A Comparison of Interobserver Reliability Between Orthopedic Surgeons Using the Centers for Disease Control Surgical Wound Class Definitions

J Am Acad Orthop Surg. 2021 Dec 15;29(24):1068-1071. doi: 10.5435/JAAOS-D-20-01128.


Background: The Centers for Disease Control (CDC) created a classification to help stratify surgical wounds based on contamination and risk of developing a surgical site infection. The classification includes four options (I to IV) depending on the level of contamination present. Although universally applied to a variety of surgical specialties, it is unknown whether the current system is reliable when considering orthopaedic surgeries. The purpose of this study was to compare the degree of interobserver reliability between orthopaedic surgeons using the current CDC wound class definitions.

Methods: A questionnaire containing 30 clinical vignettes was completed by 39 orthopaedic surgeons at our institution. After each vignette, respondents were asked to determine the appropriate wound class based on information provided in the vignette. The overall interobserver agreement among all participants was analyzed. In addition, respondents were queried about the adequacy of the current classification system in describing orthopaedic surgical wound class.

Results: Interobserver agreement was poor at 66%, with a coefficient of concordance of 0.48. Only six physicians (15.4%) thought that the current wound classification system adequately covered orthopaedic surgery.

Conclusions: There is poor interobserver reliability using the CDC surgical wound class definitions for orthopaedic surgeries. Alternate definitions are needed to improve the validity of the system for subspecialty procedures.

MeSH terms

  • Centers for Disease Control and Prevention, U.S.
  • Humans
  • Orthopedic Surgeons*
  • Reproducibility of Results
  • Surgical Wound Infection
  • Surgical Wound*
  • United States