title: The Effect of Air Tourniquet on Interleukin-6 Levels in Total Knee Arthroplasty.
abstract: BACKGROUND
  Air tourniquet-induced skeletal muscle injury increases the concentrations of some cytokines such as interleukin-6 (IL-6) in plasma. However, the effect of an air tourniquet on the IL-6 concentrations after total knee arthroplasty (TKA) is unclear. We therefore investigated the impact of tourniquet-induced ischemia and reperfusion injury in TKA using the IL-6 level as an index.
  
  
  METHODS
  Ten patients with primary knee osteoarthrosis who underwent unilateral TKA without an air tourniquet were recruited (Non-tourniquet group). We also selected 10 age- and sex-matched control patients who underwent unilateral TKA with an air tourniquet (Tourniquet group). Venous blood samples were obtained at 3 points; before surgery, 24 h after surgery, and 7 days after surgery. The following factors were compared between the two groups; IL-6, C-reactive protein (CRP), creatine phosphokinase (CPK), the mean white blood cell (WBC) counts, and the maximum daily body temperatures.
  
  
  RESULTS
  The IL-6 level at 24 h after surgery was significantly higher than that at any other point (p<0.01). No significant differences were observed in the WBC count, the body temperature, or the CRP, CPK, or IL-6 levels of the two groups at any of the time points.
  
  
  CONCLUSIONS
  The effect of ischemia and reperfusion due to the use of an air tourniquet on increasing the IL-6 level was much smaller than that induced by surgical stress in TKA.
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, Saga University, Nabeshima 5-1-1, Saga 849-8501, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Tsunoda
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, Saga University, Nabeshima 5-1-1, Saga 849-8501, Japan.
authors.forename: Motoki
authors.initials: M
authors.lastname: Sonohata
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, Saga University, Nabeshima 5-1-1, Saga 849-8501, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Kugisaki
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, Saga University, Nabeshima 5-1-1, Saga 849-8501, Japan.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Someya
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, Saga University, Nabeshima 5-1-1, Saga 849-8501, Japan.
authors.forename: Hidefumi
authors.initials: H
authors.lastname: Honke
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, Saga University, Nabeshima 5-1-1, Saga 849-8501, Japan.
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Komine
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, Saga University, Nabeshima 5-1-1, Saga 849-8501, Japan.
authors.forename: Masataka
authors.initials: M
authors.lastname: Izumi
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, Saga University, Nabeshima 5-1-1, Saga 849-8501, Japan.
authors.forename: Shuya
authors.initials: S
authors.lastname: Ide
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, Saga University, Nabeshima 5-1-1, Saga 849-8501, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Mawatari
keywords: Interleukin 6; Ischemia; Pneumatic tourniquet; Reperfusion injury; Surgical stress; Total knee arthroplasty