White blood cell/bone marrow imaging yielded poor diagnosis of chronic shoulder PJI
Use of white blood cell/bone marrow single-photon emission CT with standard CT for diagnosis of chronic infection in failed shoulder arthroplasty yielded low negative predictive values, high positive predictive values and poor accuracy, according to published results.
Researchers referred 71 patients with failed shoulder arthroplasty to a diagnostic program that included undergoing white blood cell/bone marrow single-photon emission CT with standard CT. Researchers obtained and cultured biopsy specimens for 14 days if a patient underwent revision. Biopsy specimens were used as a reference to determine the diagnostic performance of white blood cell/bone marrow imaging.
Overall, 49 patients underwent a white blood cell/bone marrow scan. Of these patients, 59% underwent revision. Results showed 11 patients had infection and, of the patients who underwent revision, white blood cell/bone marrow scans were true positive in two patients; were false negative in nine patients; and were true negative in 18 patients. Researchers found a sensitivity and specificity of 0.18 and 1, respectively, in the ability of white blood cell/bone marrow imaging to detect shoulder periprosthetic joint infection. White blood cell/bone marrow imaging also had a positive predictive value of 1 and a negative predictive value of 0.67, according to results. Researchers noted no positive white blood cell/bone marrow scans were found among patients infected with Cutibacterium acnes. These patients also showed no preoperative or perioperative signs of infection, according to researchers.
“Because of the high risk of an inconclusive result, [white blood cell/bone marrow] WBC/BM SPECT CT cannot currently be recommended as a method of screening a failed shoulder arthroplasty for [periprosthetic joint infection] PJI,” the authors wrote. “Thus, future research in functional imaging of shoulder arthroplasties should focus on modalities that can detect chronic low-grade infections or even target specific molecules produced by the most frequent disease-causing bacteria. Furthermore, studies investigating preoperative diagnostic tools should incorporate histologic analysis of biopsy samples.” – by Casey Tingle
Disclosures: Falstie-Jensen reports he received a grant from Aarhus University. Please see the full study for a list of all other authors’ relevant financial disclosures.