Tourniquet induced ischemia-reperfusion syndrome (IRS) may trigger systemic inflammatory response following a total knee arthroplasty. The IRS will be studied in a prospective randomized controlled study in humans undergoing total knee arthroplasty, by measuring blood inflammatory mediators and blood gases.

Materials and Methods: Forty four (n=44) patients (female/male: 35/9 male) with a mean age of 72 years, undergoing primary total knee arthroplasty for osteoarthritis, were prospectively randomized in two groups. 22 patients operated with tourniquet [tourniquet group (TG)] and 22 patients operated without a tourniquet [non-tourniquet group (NTG)]. The mean overall ischemia time was 90 minutes. Arterial and venous blood samples were collected preoperatively, and at 1, 2, 3, 6, 24, 48 hours postoperatively. The pro-inflammatory (IL-1b, IL-6) and anti-inflammatory cytokines (IL-10) as well as the adhesion molecules (ICAM, VCAM), the CRP and blood counts were measured and correlated with the blood gases.

Results: Patients in TG had higher cytokine and inflammatory mediators values, compared to the NTG group especially during the sixth postoperative hour and the first postoperative day. The most abrupt changes were evident in the patients with the highest preoperative levels of cytokines and inflammatory mediators especially when the ischemia time was more than 90 minutes. Male patients demonstrated the most significant changes.

Discussion: The use of the tourniquet triggers the systemic inflammatory response. The most remarkable changes in inflammatory mediators are evident during the sixth postoperative hour and the first posoperative day. Tourniquet may be used for Total knee Replacement but care should be taken to decrease the ischemia time to the absolutely necessary specifically in males.