Table 2 Infection characteristics of 75 patient with enterococcal PJI
Variable | All episodes (n = 75) | Monomicrobial (n = 37) | Polymicrobial (n = 38) | P value |
|---|---|---|---|---|
Infection manifestation according to the time after last surgery | ||||
Early | 27 (36) | 10 (27) | 17 (45) | 0.150 |
Delayed | 30 (40) | 17 (46) | 13 (34) | 0.351 |
Late | 18 (24) | 10 (27) | 8 (21) | 0.597 |
Median delay from last revision to PJI (range) - months | 8.7 (0.5–336) | 10.2 (0.3–336) | 5.0 (0.4–133) | 0.588 |
Median delay from primary implantation of prosthesis to PJI (range) - months | 47.7 (0.3–418) | 36.4 (0.3–418) | 56.6 (0.4–373) | 0.810 |
Presumed route of infection | ||||
Perioperativea | 61 (81) | 25 (68) | 36 (95) | 0.003 |
Hematogenous | 13 (17) | 12 (32) | 1 (3) | < 0.001 |
Direct extension by adjacent infectious focus (contiguous) | 1 (1) | – | 1 (3) | |
Signs and symptoms | ||||
Joint pain | 48/70 (69) | 22/32 (69) | 26/38 (68) | 1.000 |
Local signs | 46 (61) | 20 (54) | 26 (68) | 0.241 |
Sinus tract | 16 (21) | 3 (8) | 13 (34) | 0.010 |
Prosthesis loosening in x-ray | 16 (21) | 5 (14) | 11 (29) | 0.158 |
Laboratory results at admission | ||||
Serum C-reactive protein | ||||
Median (range) - mg/l | 36 (1–295) | 45 (12–229) | 36 (1–295) | 0.936 |
Increased (> 10 mg/l) | 63 (84) | 30 (81) | 33 (87) | 0.544 |
White blood cell count | ||||
Median (range) – G/l | 7.9 (3.2–34.23) | 7.4 (4.8–22.4) | 8.3 (3.2–34.3) | 0.992 |
Increased (> 10 G/l) | 18 (24) | 8 (22) | 10 (26) | 0.788 |
Synovial fluid leukocyte count | ||||
Increased valueb | 25/29 (86) | 16/17 (94) | 9/12 (75) | 0.279 |
Median absolute count (range) - 103/μl | 20.3 (0.42–160) | 23 (1.8–160) | 7.1 (0.4–140) | 0.097 |
Histopathology consistent with infection | 53/61 (87) | 26/28 (93) | 27/33 (82) | 0.294 |