title: Cytokine patterns after tourniquet-induced skeletal muscle ischaemia reperfusion in total knee replacement.
abstract: 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.
  
  
  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.
authors.affiliation: Department of Orthopaedics, Rikshospitalet-Radiumhospitalet Medical Centre, University of Oslo, Oslo, Norway. tck@start.no
authors.forename: T
authors.initials: T
authors.lastname: Clementsen
authors.forename: O
authors.initials: O
authors.lastname: Reikerås
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee; D005260:Female; D006801:Humans; D007511:Ischemia / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000098:blood supply*; D015424:Reperfusion; D014111:Tourniquets