Serum interleukin-6 response to elective total hip replacement surgery

The focus of this work was to study the serum interleukin-6 (IL-6) response to total hip replacement. Twenty-one patients received an uncemented total hip prosthesis. Venous samples for IL-6 determination were drawn before and after surgery. The IL-6 response was significant, and a peculiar heterogeneity of response was apparent: the medians of peak levels (82.3 pg/ml) and of areas under the response curve (51.8 pg/ml) distinguished between IL-6 high responders (HR) and IL-6 low responders (LR; p<0.0001). No difference was found in the gender composition of these groups, whereas the HR patients were older than the LR patients (p<0.05). The amount of IL-6 increase was found to correlate with patient age, whereas its slope was found to correlate with the duration of the surgical procedure. Moreover, the HR group presented a higher degree of hyperthermia in the days after surgery compared with the LR patients, without evidence of differences in postoperative complications, time to mobilisation, or length of stay in hospital. The main finding of our study was the evidence of a remarkable variability between individuals in the IL-6 response to surgery. Future studies are needed to identify the factors involved in the regulation of the cytokine response to surgery

Circulating Cytokines after Hip and Knee Arthroplasty: A Preliminary Study

Several studies show cytokine concentrations in the peripheral blood are associated with inflammatory activity and surgical trauma. Cytokine concentrations have more rapid increase and quicker return to normal values than either C-reactive protein or erythrocyte sedimentation rate – a matter of hours rather than weeks; some studies suggest they are better predictors of postoperative infection than C-reactive protein and erythrocyte sedimentation rate. Threshold levels of interleukin-6 after joint arthroplasty have been determined, but levels of other potentially useful cytokines (tumor necrosis factor-α, interleukin-8, interleukin-10, etc) are not known. We measured the serum levels of 25 different cytokines before and after hip and knee arthroplasties and identified those associated with surgical trauma. Peripheral venous blood samples (one preoperative and three postoperative) from 49 patients undergoing hip or knee arthroplasty were analyzed by laser chromatography. Three of the 25 cytokines had a relationship with postsurgical trauma, which included one deep infection. Serum levels of these three cytokines might be useful to identify periprosthetic infections during the early postoperative period when C-reactive protein and erythrocyte sedimentation rate remain elevated