title: Neutrophil-to-lymphocyte ratio (NLR) distribution shows a better kinetic pattern than C-reactive protein distribution for the follow-up of early inflammation after total knee arthroplasty.
abstract: OBJECTIVE
  This study aimed to assess whether the neutrophil-to-lymphocyte ratio (NLR) distribution could have a better kinetic pattern than C-reactive protein (CRP) distribution to evaluate early post-operative inflammation after total knee arthroplasty (TKA).
  
  
  METHODS
  A prospective study was performed on 587 patients. CRP and NLR were collected pre-operatively and at post-operative days 2, 4, 21 and 42. Mean peak values and distribution were compared between CRP and NLR.
  
  
  RESULTS
  Mean CRP levels were 163, 161, 9 and 7 mg/L, respectively, at days 2, 4, 21 and 42. Mean NLR levels were 5, 3.5, 2.6 and 2.5, respectively, at days 2, 4, 21 and 42. At days 21 and 42, 20 % (102/503) and 21 % (93/433) of patients had not reached normal CRP levels. At day 21, there were 4.5 % (23/503) of patients with a NLR > 5 and 1 % (5/503) with an NLR > 10. At day 42, there were 5.5 % (24/433) of patients with an NLR > 5 and 0.7 % (3/433) with an NLR > 10.
  
  
  CONCLUSIONS
  NLR has a faster normalization than CRP. It is potentially a better biomarker to follow post-operative inflammation or early infection after TKA.
  
  
  METHODS
  II.
authors.affiliation: Department of Internal Medicine Infectious Diseases and Perioperative Medicine, Université Catholique de Louvain, Cliniques Universitaires St-Luc, 10 Avenue Hippocrate, 1200, Brussels, Belgium. jean.yombi@uclouvain.be.
authors.forename: J C
authors.initials: JC
authors.lastname: Yombi
authors.affiliation: Department of Orthopedic Surgery, Université Catholique de Louvain, Cliniques Universitaires St-Luc, 10 Avenue Hippocrate, 1200, Brussels, Belgium.
authors.forename: P E
authors.initials: PE
authors.lastname: Schwab
authors.affiliation: Department of Orthopedic Surgery, Université Catholique de Louvain, Cliniques Universitaires St-Luc, 10 Avenue Hippocrate, 1200, Brussels, Belgium.
authors.forename: E
authors.initials: E
authors.lastname: Thienpont
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007249:Inflammation / Q000175:diagnosis*; D007958:Leukocyte Count; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000378:metabolism*; D011183:Postoperative Complications / Q000175:diagnosis*; D011446:Prospective Studies
chemical_list: D015415:Biomarkers; D002097:C-Reactive Protein
keywords: C-reactive protein; Inflammation; Neutrophil-to-lymphocyte ratio; Total knee arthroplasty