Pre-revision tissue biopsy (PTB) for culture has been utilized as a diagnostic tool in the evaluation for periprosthetic joint infection (PJI) among patients with painful shoulder arthroplasty.
These authors conducted a systematic review to determine the sensitivity (SN), specificity (SP), negative predictive value (NPV), and positive predictive value (PPV) of PTB culture results compared with culture at the time of subsequent revision surgery and to report the current indications and protocols described for use of PTB.
Studies were included if an arthroscopic or open tissue biopsy was performed in patients who had previously undergone anatomic total shoulder arthroplasty, shoulder hemiarthroplasty, or reverse total shoulder arthroplasty as a separate procedure prior to revision of components, if applicable.
The analysis was performed
defining 1 positive PTB culture as “infection” and again
defining 2 positive cultures as “infection.”
Four total studies encompassing 72 patients met inclusion criteria. All studies were small (N = 13-23), retrospective series, with all but 12 biopsies performed arthroscopically. Sixty-five patients (90.2%) underwent subsequent revision surgery and biopsy.
Twenty-three of these patients (35.4%) had at least one positive culture with PTB and revision surgery biopsy.
For 1 positive PTB, the SN of PTB was 92.0%, SP 70.0%, PPV 65.7%, and NPV 93.3%.
For 2 positive PTB, the SN of PTB was 100%, SP 50.0%, PPV 33.3%, and NPV 100%.
The authors concluded that pre-revision tissue biopsy has high negative predictive value.
Comment: A few questions arise:
(1) What does it mean if the pre-revision tissue biopsy is positive and the revision biopsy culture is negative (as happened in 12 cases)? Where did the bugs go?
(2) Doesn't the chance of having 1 (or 2) positive cultures relate to the number of specimens sent to the lab?
This review of four publications suggests that
a negative pre revision tissue culture is rarely associated with positive intra-operative cultures, whereas a positive pre revision tissue culture may or may not be associated with positive intra-operative cultures.
Thus the surgeon may use a pre-revision tissue culture when she or he is considering leaving some or all of the implants in place.
On the other hand, pre-revision tissue cultures may be of less value when prosthesis exchange is planned.
The questions to be answered are
-to what degree might a pre-revision surgical biopsy procedure change what is done at revision for a failed shoulder arthroplasty?
and
-is the cost and risk of the additional biopsy procedure offset by the value of the information gained?
We find that substantial information regarding the risk of a periprosthetic infection can be gained without an added surgical procedure, using such patient characteristics as
(1) younger age
(2) male sex
(3) supplemental testosterone
(4) a honeymoon period of good comfort and function after the arthroplasty before the otherwise unexplained onset of pain and or stiffness
(5) radiographic humeral component loosening.
Consistent with the results of this review, we find that a normal result of a fluid aspirate, CBC, sed rate, CRP, and intraoperative histology are not useful in ruling out a Cutibacterium periprosthetic infection.
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