Table 3.
Diagnostic Accuracy for Grouped Parameters in 498 Patients with Aseptic Loosening and Prosthetic Joint Infection (18 early, 35 delayed and 77 late)
| AL | PJI | Specificity (%) | Sensitivity (%) | PPV (%) | NPV (%) | ROC area | P-value* | |
|---|---|---|---|---|---|---|---|---|
| TN/total | TP/total | (95% CI) | (95% CI) | (95% CI) | (95% CI) | (95% CI) | ||
| CRP + Synovial fluid culture | ||||||||
| All patients | 261/309 | 91/114 | 84.5 (79.9–88.3) | 79.8 (71.3–86.8) | 65.5 (56.9–73.3) | 91.9 (88.1–94.8) | 0.822 (0.779–0.863) | 0.073 |
| Early | 10/13 | 12/14 | 76.9 (46.2–95.0) | 85.7 (57.2–98.2) | 80.0 (51.9–95.7) | 83.3 (51.6–97.9) | 0.813 (0.660–0.966) | |
| Delayed | 14/17 | 30/33 | 82.4 (56.6–96.2) | 90.9 (75.7–98.1) | 90.9 (75.7–98.1) | 82.4 (56.6–96.2) | 0.866 (0.760–0.972) | |
| Late | 237/279 | 49/67 | 84.9 (80.2–88.9) | 73.1 (60.9–83.2) | 53.8 (43.1–64.4) | 92.9 (89.1–95.8) | 0.790 (0.733–0.848) | |
| CRP + Peri-implant tissue culture | ||||||||
| All patients | 310/367 | 110/128 | 84.5 (80.4–88.0) | 85.9 (78.7–91.4) | 65.9 (58.1–73.0) | 94.5 (91.5–96.7) | 0.852 (0.817–0.888) | 0.331 |
| Early | 10/13 | 16/16 | 76.9 (46.2–95.0) | 100 (79.4–100) | 84.2 (60.4–96.6) | 100 (69.2–100) | 0.885 (0.765–1.000) | |
| Delayed | 20/23 | 32/35 | 87.0 (66.4–97.2) | 91.4 (76.9–98.2) | 91.4 (76.9–98.2) | 87.0 (66.4–97.2) | 0.892 (0.807–0.977) | |
| Late | 280/331 | 62/77 | 84.6 (80.2–88.3) | 80.5 (69.9–88.7) | 54.9 (45.2–64.2) | 94.9 (91.8–97.1) | 0.826 (0.777–0.874) | |
| CRP + Sonicate fluid culture | ||||||||
| All patients | 309/367 | 119/128 | 84.2 (80.1–87.8) | 93.0 (87.1–96.7) | 67.2 (59.8–74.1) | 97.2 (94.7–98.7) | 0.886 (0.857–0.915) | 0.532 |
| Early | 10/13 | 15/16 | 76.9 (46.2–95.0) | 93.8 (69.8–99.8) | 83.3 (58.6–96.4) | 90.9 (58.7–99.8) | 0.853 (0.719–0.987) | |
| Delayed | 20/23 | 34/35 | 87.0 (66.4–97.2) | 97.1 (85.1–99.9) | 91.9 (78.1–98.3) | 95.2 (76.2–99.9) | 0.921 (0.845–0.996) | |
| Late | 279/331 | 70/77 | 84.3 (79.9–88.0) | 90.9 (82.2–96.3) | 57.4 (48.1–66.3) | 97.6 (95.0–99.0) | 0.876 (0.838–0.914) | |
| Histology + Peri-implant tissue culture | ||||||||
| All patients | 367/368 | 123/128 | 99.7 (98.5–100) | 96.1 (91.1–98.7) | 99.2 (95.6–100) | 98.7 (96.9–99.6) | 0.979 (0.962–0.996) | 0.061 |
| Early | 13/13 | 18/18 | 100 (75.3–100) | 100 (81.5–100) | 100 (81.5–100) | 100 (75.3–100) | 1.000 (1.000–1.000) | |
| Delayed | 24/24 | 32/33 | 100 (85.8–100) | 97.0 (84.2–99.9) | 100 (89.1–100) | 96.0 (79.6–99.9) | 0.985 (0.955–1.000) | |
| Late | 330/331 | 73/77 | 99.7 (98.3–100) | 94.8 (87.2–98.6) | 98.6 (92.7–100) | 98.8 (97.0–99.7) | 0.973 (0.947–0.998) | |
| Histology + Sonicate fluid culture | ||||||||
| All patients | 366/368 | 128/128 | 99.5 (98.1–99.9) | 100 (97.2–100) | 98.5 (94.3–99.8) | 100 (99.0–100) | 0.997 (0.993–1.000) | 0.37 |
| Early | 13/13 | 18/18 | 100 (75.3–100) | 100 (81.5–100) | 100 (81.5–100) | 100 (75.3–100) | 1.000 (1.000–1.000) | |
| Delayed | 23/24 | 33/34 | 95.8 (78.9–99.9) | 100 (89.4–100) | 97.1 (84.7–99.9) | 100 (85.2–100) | 0.978 (0.938–1.000) | |
| Late | 330/331 | 77/77 | 99.7 (98.3–100) | 100 (95.3–100) | 98.7 (93.1–100) | 100 (98.9–100) | 0.999 (0.996–1.000) | |
| Peri-implant tissue culture + Sonicate fluid culture | ||||||||
| All patients | 365/368 | 111/130 | 99.2 (97.6–99.8) | 85.4 (78.1–91.0) | 97.4 (92.5–99.5) | 95.1 (92.4–97.0) | 0.923 (0.892–0.954) | 0.32 |
| Early | 13/13 | 16/18 | 100 (75.3–100) | 88.9 (65.3–98.6) | 100 (79.4–100) | 86.7 (59.5–98.4) | 0.945 (0.870–1.000) | |
| Delayed | 23/24 | 33/34 | 95.8 (78.9–99.9) | 94.3 (80.8–99.3) | 97.1 (84.7–99.9) | 92.0 (74.0–99.0) | 0.951 (0.894–1.000) | |
| Late | 329/331 | 62/77 | 99.4 (97.8–99.9) | 80.5 (69.9–88.7) | 96.9 (96.2–99.6) | 95.6 (92.9–97.5) | 0.900 (0.855–0.944) | |
AL aseptic loosening, PJI prosthetic joint infection, TN true negative, TP true positive, CI confidence interval, PPV positive predictive value, NPV negative predictive value, CRP C-reactive protein
*Two sided P-value Test of equality of independent ROC areas in the three groups of patients with PJI: early, delayed and late