Table 2.
Summary findings on the performance of synovial fluid biomarkers in identifying persistent infection in patients with spacers
| Publication | Population | Studied biomarker (cutoff) | Sensitivity | Specificity | Positive predictive value | Negative predictive value | Accuracy |
|---|---|---|---|---|---|---|---|
| Frangiamore et al. 2016 [49] | 32 spacers | IL-6 (8.7 pg/mL) | 0% | 89% | 0% | 86% | 78% |
| Kheir et al. 2017 [48] | 77 spacers | Leukocyte esterase (+ 2) | 26% | 100% | 100% | 87% | 63% |
| Stone et al. 2019 [44] | 52 spacers (22 hips and 30 knees) | Alpha-defensin | 71% | 98% | 83% | 96% | - |
| Samuel et al. 2019 [47] | 69 spacers (26 hips and 43 knees) | Alpha-defensin | 7% | 89% | 14% | 79% | 83% |
| Bielefeld et al. 2021 [40] | 20 spacers (8 hips and 12 knees) | Alpha-defensin (4.8 ng/mL) | 33% | 53% | - | - | 41% |
| Leukocyte esterase (+ 2) | 0% | 100% | - | - | - | ||
| Owens et al. 2022 [45] | 87 spacers (27 hips and 60 knees) | Alpha-defensin | 6%a | 100% | - | 94% | 83% |
aIf you consider one undeterminate AD test result in an infected case as not negative