Objective: Extremity surgery performed under tourniquet control causes one of the most common forms of skeletal muscle ischaemia-reperfusion injury in clinical practice. The aim of this study was to investigate the systemic and local inflammatory response after tourniquet-induced skeletal muscle ischaemia-reperfusion injury in patients undergoing total knee replacement. It was our hypothesis that local inflammatory responses in a surgical wound under tourniquet-induced ischaemia cause an excessive overflow of cytokines to the systemic circulation in the reperfusion phase.
Material and methods: Blood was sampled before and after surgery in nine patients given total knee replacement. Samples from ischaemic and non-ischaemic limbs and from drained blood were analysed for pro-inflammatory and anti-inflammatory cytokines.
Results: Surgery induced significant increases of IL-6 (p = 0.007) in the non-ischaemic (systemic) limb and in drained blood (p = 0.032), with highest levels 4 h after operation. The increased IL-6 in the ischaemic limb was non-significant. IL-1 beta was not detectable under surgery, from either the traumatized limb or from the non-traumatized limb, nor were TNFalpha and IL-10 significantly influenced by surgery.
Conclusions: Knee replacement trauma performed under ischaemia, is associated with modest systemic inflammatory reactions with no spillover of increased IL-6 from the traumatized area in the reperfusion phase.