Table I.
Demographics and clinical profile of the patients.
| Baseline characteristics | Total |
|---|---|
| Patients, n | 195 |
| Male, n (%) | 82/195 (42.1) |
| Female, n (%) | 113/195 (57.9) |
| Mean age, yrs (SD) | 70.24 (2.5) |
| Mean BMI, kg/m2 (SD) | 30.62 (8.62) |
| THAs, n (%) | 59/195 (30.3) |
| TKAs, n (%) | 136/195 (69.7) |
| ASA grade, n (%)* | |
| I | 9/268 (3.3) |
| II | 172/268 (64.2) |
| III | 87/268 (32.5) |
| Synovial fluid samples, n | 268 |
| Samples collected from patients on antibiotic therapy, n (%)† | 122/268 (45.5) |
| ICM 2018 PJI criteria, n (%) | |
| Infected | 141/268 (52.6) |
| Chronic | 84/141 (59.6) |
| Early acute | 31/141 (22.0) |
| Late acute | 26/141 (18.4) |
| Non-infected | 89/268 (33.2) |
| Inconclusive | 38/268 (14.2) |
| Single-positive cultures, n (%) | |
| Infected | 25/141 (18.4) |
| Non-infected | 32/89 (36) |
| Inconclusive | 10/38 (26.3) |
| Median number of previous revisions (IQR) | 2 (0 to 2) |
The ASA grade was determined per case and not per patient. The population selected for the study included recurrent patients who had more than one synovial fluid sample evaluated in the study. These patients underwent multiple revision surgeries with changes in ASA grade over time.
The high number of samples collected from patients on ongoing antibiotic therapy was specifically chosen for the study to increase the number of cases that may have been particularly problematic for conventional microbiological analysis.
ASA, American Society of Anesthesiologists; ICM, International Consensus Meeting; IQR, interquartile range; PJI, periprosthetic joint infection; SD, standard deviation; THA, total hip arthroplasty; TKA, total knee arthroplasty.