title: Characteristics and significance of fever during 4 weeks after primary total knee arthroplasty.
abstract: OBJECTIVE
  Most previous studies on postoperative fever (POF; ≥38 °C) after total knee arthroplasty (TKA) have reported findings from only the immediate postoperative days (PODs). The hypothesis of the current study is that 4 weeks of follow-up may reveal differences in the characteristics of POF and fever-related factors between a normal inflammatory response and an early acute infection-related response.
  
  
  METHODS
  A total of 400 consecutive TKAs (314 patients) were retrospectively investigated. Patients were stratified into those who developed an early acute periprosthetic infection that required subsequent surgical treatment (STG; n = 5 TKAs) and those who did not (non-STG; n = 395 TKAs).
  
  
  RESULTS
  Among the 400 knees, 149 (37 %) developed POF, with most reaching a maximum temperature (MT) on POD 0. In 13 TKA patients who had POF with a peak daily temperature ≥38 °C during postoperative weeks 2-4, the causes of POF were respiratory and urinary tract infections (n = 5 for each), superficial infection (n = 2), and periprosthetic infection (n = 1). The STG and non-STG differed significantly with regard to the rate of POF (p = 0.0205) and MT (p = 0.0003), including MTs less than 38 °C, during postoperative weeks 2-4. All five STG patients had elevated C-reactive protein levels and local symptomatic findings before the additional surgery.
  
  
  CONCLUSIONS
  The occurrence of POF and MT along with elevated C-reactive protein and local symptomatic findings at 2-4 weeks postoperatively may indicate the need for a positive fever workup to recognize early acute periprosthetic infection.
authors: Ishii Orthopaedic and Rehabilitation Clinic, 1089 Shimo-Oshi, Gyoda, Saitama, 361-0037, Japan, ishii@sakitama.or.jp.
authors: Yoshinori
authors: Y
authors: Ishii
authors: Hideo
authors: H
authors: Noguchi
authors: Mitsuhiro
authors: M
authors: Takeda
authors: Junko
authors: J
authors: Sato
authors: Satoshi
authors: S
authors: Takayama
authors: Shin-ichi
authors: S
authors: Toyabe
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000601:surgery; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D002097:C-Reactive Protein / Q000032:analysis; D005260:Female; D005334:Fever / Q000097:blood / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D007249:Inflammation; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery; D011184:Postoperative Period; D016459:Prosthesis-Related Infections / Q000097:blood / Q000453:epidemiology / Q000209:etiology; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000209:etiology; D012189:Retrospective Studies; D013997:Time Factors; D014552:Urinary Tract Infections / Q000453:epidemiology / Q000209:etiology
chemical_list: D002097:C-Reactive Protein