OBJECTIVE  To survey the causes of a suspected hospital-associated infection outbreak following high tibial osteotomy （HTO） in orthopedic department, implement timely infection control measures, and evaluate the effectiveness of these measures.

METHODS  From Nov. 14, 2024 to Dec. 2, 2024, totally 5 of multiple patients who underwent HTO in the same treatment group at the orthopedic department of a large tertiary general teaching hospital exhibited poor incision healing. The hospital immediately conducted a suspected outbreak survey, determined case definitions, searched for cases, investigated causes and took control measures.

RESULTS  According to the case definition and case search, from Jan. 1, 2024 to Dec. 12, 2024, 139 patients underwent HTO in this treatment group, with 8 cases （5.76%） occurring. During the same period in 2023, a total of 115 patients underwent HTO, with no case occurring （0.00%）, and the difference was statistically significant （P=0.024）. Case survey revealed that since Apr. 18, 2024 onset of infection, absorbable hemostatic materials have been used in this treatment group for HTO to control bleeding on the bone setting surface. From Apr. 18 to Nov. 6, 77 surgical patients all used hemostatic material I, with 3 cases occurring. From Nov. 7 to Dec. 12, due to centralized procurement of disposable low-value consumables, 15 surgical patients all used hemostatic material II with a production batch number of "24090801", with 5 cases occurring. The difference in case risk before and after the change in hemostatic materials was statistically significant （P＜0.001）. The results of the retrospective cohort study showed that patients who used hemostatic materials during surgery had a higher risk probability of postoperative tissue space hematoma and pitting edema at the incision site than those who did not use them （log-rank test, P=0.013）, while there was no difference in the cumulative risk of tissue space hematoma and pitting edema between patients who used hemostatic material I and hemostatic material II （log-rank test, P=0.110）. After adjusting for preoperative coagulation markers, the cumulative probability of risk before and after the use of hemostatic materials showed no abnormalities （log-rank test, P=0.082. P=0.090）. Six months after the treatment group stopped the use of absorbable hemostatic materials, no such phenomena occurred in patients after HTO, indicating effective control of the event.

CONCLUSIONS  The suspected hospital-associated infection outbreak following HTO in orthopedic department is confirmed to be a false outbreak, potentially resulting from an adverse event caused by the use of hemostatic materials. Attention should be paid to adverse events induced by biological materials and to symptoms of poor incision healing caused by postoperative bleeding in patients with abnormal preoperative coagulation markers.