White blood cell counts and differential in synovial fluid of aseptically failed total knee arthroplasty

J Arthroplasty. 2000 Apr;15(3):301-4. doi: 10.1016/s0883-5403(00)90578-3.


A cell count and differential was obtained on synovial fluid samples from 79 total knee arthroplasties undergoing revision for aseptic failure over a 5-year period. The mean white blood cell count (WBC) was 782/mL (range, 11-7,200/mL). The mean percentage of monocyte cells was 87%, and the mean polymorphonuclear leukocyte (PML) cell count was 13%. Eight patients (10.4%) had leukocyte cell counts >2,000. Five knees in 4 patients with rheumatoid arthritis had PML counts >50%. There was a single postoperative infection. In patients with osteoarthritis as a primary diagnosis, a synovial WBC of <2,000 and a differential with <50% PMLs had a 98% negative predictive value for the absence of infection. Key words: synovial fluid, cell count and differential, failed total knee arthroplasty, revision total knee arthroplasty.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Arthroplasty, Replacement, Knee*
  • Female
  • Humans
  • Leukocyte Count*
  • Male
  • Middle Aged
  • Prospective Studies
  • Prosthesis Failure
  • Reoperation
  • Synovial Fluid / cytology*