- infected prosthesis can be difficult to evaluate and diagnose;
- however if preoperative aspiration, white cell scan, & sed rate rate are negative, then the chance of doing a successful revision
arthroplasty w/o subsequent infection is good;
- Criteria for Infection:
- at the time of surgery, biopsied material that contains more than 5-10 WBC per HPF (40x) may indicate sepsis;
- sensitivity: about 84% (w/ either 5 or 10 WBC per HPF)
- specificity: 99% using 10 WBC per HPF;
- results are improved by using multiple samples and presence of more than 5 WBC per HPF in more than 5 samples is good evidence for infection;
- for WBC to be counted, they must have defined cytoplasmic borders;
- true positive:
- peri-implant membrane: high concentration of neutrophils is essentially diagnostic of ongoing infection;
- more than 15 neutrophils and, in the absence of an underlying inflammatory arthropathy, strongly supports the diagnosis of infection;
- between 5-15 PMNs supports the diagnosis of infection;
- false negative results:
- in cases where a chronic low grade infection is present (low virulent organism) signs of acute inflammation may be absent;
- in the study by Segawa, et al (1999), only 8 out of 30 patients with chronic joint infection demonstrated signs of acute inflammation;
- Technical Pearls:
- avoid using scar tissue as a sample;
- tissue should for sample should have pink-tan color (as opposed to white scar tissue)
Intraoperative frozen section analysis in revision total joint arthroplasty.
The role of intraoperative frozen sections in revision total joint arthroplasty.
Infection After Total Knee Arthroplasty. A Retrospective Study of the Treatment of Eighty-One Infections.
Analysis of Frozen Sections of Intraoperative Specimens Obtained at the Time of Reoperation After Hip or Knee Resection Arthroplasty for the Treatment of Infection
The Reliability of Analysis of Intraoperative Frozen Sections for Identifying Active Infection during Revision Hip or Knee Arthroplasty
Diagnosis of infection by frozen section during revision arthroplasty.
Histological and microbiological findings in non-infected and infected revision arthroplasty tissues. The OSIRIS Collaborative Study Group. Oxford Skeletal Infection Research and Intervention Service.
Frozen section biopsy assessment for the presence of polymorphonuclear leukocytes in patients undergoing revision of arthroplasties.