Diagnostic accuracy of preoperative percutaneous synovial biopsy and aspirate compared with open biopsy for prosthetic shoulder infections

Peter Lapner; Diane Nam; Amar Cheema; Adnan Sheikh; Taryn Hodgdon; J Whitcomb Pollock; Tim Ramsay; Elham Sabri; Darren Drosdowech; Katie McIlquham; Baldwin Toye; Dominique Rouleau

doi:10.1016/j.jse.2024.08.016

Diagnostic accuracy of preoperative percutaneous synovial biopsy and aspirate compared with open biopsy for prosthetic shoulder infections

J Shoulder Elbow Surg. 2024 Oct 9:S1058-2746(24)00714-6. doi: 10.1016/j.jse.2024.08.016. Online ahead of print.

Authors

Affiliations

¹ Division of Orthopedic surgery, The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada. Electronic address: plapner@toh.ca.
² Division of Orthopaedic Surgery, Sunnybrook Health Sciences Centre, Toronto, ON, Canada; Department of Surgery, University of Toronto, Toronto, ON, Canada.
³ Division of Orthopedic surgery, The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada.
⁴ Department of Radiology, University of British Columbia, Vancouver, BC, Canada.
⁵ Department of Medical Imaging, The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada.
⁶ Clinical Epidemiology Program, The Ottawa Hospital Research Institute, Ottawa, ON, Canada.
⁷ Roth|McFarlane Hand and Upper Limb Centre, St. Joseph's Health Care, Western University, London, ON, Canada.
⁸ Division of Infectious Diseases, The Ottawa Hospital, University of Ottawa, Ottawa, ON, Canada.
⁹ Hôpital du Sacré-Coeur de Montreal, Universite de Montreal, Montreal, QC, Canada.

PMID: 39389453
DOI: 10.1016/j.jse.2024.08.016

Abstract

Background: Shoulder arthroplasty revision is associated with a high prevalence of prosthetic infection, and diagnosis remains difficult. The primary aim of the study was to determine the diagnostic accuracy of percutaneous synovial biopsy (PSB) and joint aspiration compared with open culture results in detecting infection in revision shoulder arthroplasty. The second aim was to determine whether biopsy location within the shoulder was associated with culture status.

Methods: This was a multicenter prospective cohort study involving 4 sites and 69 patients undergoing revision shoulder arthroplasty. The cohort was 57% female with a mean age of 64 years. Preoperative fluoroscopic-guided PSBs and aspirations were carried out by a musculoskeletal radiologist before revision shoulder arthroplasty. The original prostheses consisted of hemiarthroplasties, total shoulder arthroplasties (TSAs), resurfacing TSA, reverse shoulder arthroplasties (RSAs), and antibiotic spacers. Six synovial tissue biopsies from separate regions in the shoulder were obtained both preoperatively and intraoperatively. The shoulder joint was aspirated, and synovial fluid collected, if available. Infection was considered positive in the setting of 2 or more matching positive cultures. The PSB cultures were considered "true positive" if the PSB cultures matched the open biopsy cultures.

Results: Nineteen percent had positive infection based on PSB, and 23% had confirmed culture-positive infections based on intraoperative biopsy. The diagnostic accuracy of PSB compared with open biopsy was as follows: sensitivity 0.37 (95% confidence interval [CI] 0.13-0.61), specificity 0.81 (95% CI 0.7-0.91), positive predictive value 0.37 (95% CI 0.13-0.61), negative predictive value 0.81 (95% CI 0.70-0.91), positive likelihood ratio 1.98, and negative likelihood ratio 0.77. Of the 71 patients from whom aspirates were collected, aspiration yielded synovial fluid in 33 patients. Preoperative aspiration detected no infections confirmed positive by open biopsy and correctly identified 81% of absent infections. The diagnostic accuracy of aspiration compared with open biopsy was as follows: sensitivity 0%, specificity 0.81 (95% CI 0.66-0.96), positive predictive value 0%, and negative predictive value 0.78 (95% CI 0.63-0.93). Biopsy location within the shoulder was not associated with infection status.

Discussion: Preoperative aspiration detected none of the infections proven positive via open biopsy. Although PSB was superior to synovial fluid aspirate, poor likelihood ratios suggest that PSB is not useful as an isolated test in the preoperative workup of the potentially infected patient. Biopsy location was not associated with culture status suggesting that the capsule is uniformly infected, and the location of tissue biopsies does not appear to matter.

Keywords: Shoulder infection; joint aspiration; open culture; prosthetic joint infection; shoulder arthroplasty; synovial biopsy.