White blood cell counts and differential in synovial fluid of aseptically failed total knee arthroplasty.
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.
Kersey
R
R
Section of Orthopedic Surgery, University of Arizona Health Sciences Center, Tucson, USA.
Benjamin
J
J
Marson
B
B
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011475:Prosthesis Failure; D012086:Reoperation; D013582:Synovial Fluid / Q000166:cytology*