Only 15% Ortho Surgeons ‘OK’ With Wound Classification System

Using the Centers for Disease Control (CDC) classification for the stratification of surgical wounds based on contamination and risk of developing a surgical site infection, researchers from Mayo Clinic in Jacksonville, Florida, investigated the degree of interobserver reliability between orthopedic surgeons.

Their work, “A Comparison of Interobserver Reliability Between Orthopedic Surgeons Using the Centers for Disease Control Surgical Wound Class Definitions,” was published in the December 15, 2021 edition of the Journal of the American Academy of Orthopaedic Surgeons.

Assistant Professor and Senior Associate Consultant in the Department of Orthopedic Surgery at Mayo Clinic in Florida and study co-author, Benjamin Wilke, M.D., explained the hypothesis of the study to OTW, “Accurate reporting of surgical outcomes is paramount to improving quality of care. Currently all surgical procedures are labeled using a classification system that was developed in the 1960s, intended mainly for general surgical procedures. This classification system often does not pertain to surgical wounds for subspecialty procedures. We felt that this would lead to errors in reporting and was the driver for our research.”

To test to what extent the classification system might lead to errors, the team distributed questionnaires with 30 clinical vignettes to 39 orthopedic surgeons at their institution. Participants then determined the appropriate wound class based and the interobserver agreement was analyzed. The investigators also asked respondents how adequate the existing classification system was in describing orthopedic surgical wound class.

The researchers asked their physician colleagues to assign the appropriate CDC surgical wound class as:

• TYPE I (Uninfected surgical wound in which no inflammation is encountered and the respiratory, alimentary, genital, or uninfected urinary tract is not entered. In addition, clean wounds are primarily closed and, if necessary, drained with closed drainage. Surgical incisional wounds that follow nonpenetrating (blunt) trauma should be included in this category whether they meet the criteria.)
• TYPE II (A surgical wound in which the respiratory, alimentary, genital, or urinary tracts are entered under controlled conditions and without unusual contamination. Specifically, operations involving the biliary tract, appendix, vagina, and oropharynx are included in this category, provided no evidence of infection or major break in the technique is encountered.)
• TYPE III (Open, fresh, accidental wounds. In addition, operations with major breaks in the sterile technique (e.g., open cardiac massage) or gross spillage from the GI tract, and incisions in which acute, nonpurulent inflammation is encountered are included in this category.)
• TYPE IV (Old traumatic wounds with retained devitalized tissue and those that involve existing clinical infection or perforated viscera. This definition suggests that the organisms causing postoperative infection were present in the surgical field before the operation.)

“We hypothesized that there would be low agreement amongst orthopedic surgeons when assigning a surgical wound class to clinical vignettes,” stated Dr. Wilke to OTW. “We found that interobserver agreement was poor (66%), and that only 15% of orthopedic surgeons surveyed felt that the current wound classification adequately covered orthopedic procedures.”

“We believe that updates to the wound class definitions should be considered to improve interobserver agreement amongst subspecialty practices.”