TABLE 2.
Characteristics of patients with definite prosthetic shoulder infection with sonicate fluid cultures positive for Propionibacterium acnes versus those of patients with definite prosthetic shoulder infection with sonicate fluid cultures positive for other microorganisms
| Characteristic | Sonicate fluid positive for P. acnesa (n = 9) | Sonicate fluid positive for organism(s) other than P. acnes (n = 13) | P |
|---|---|---|---|
| Demographics | |||
| Median (range) age (yr) | 56 (44-80) | 60 (54-81) | 0.22 |
| No. (%) of subjects of female gender | 0 (0) | 8 (61.5) | 0.006 |
| Clinical data (no. [%] of subjects) | |||
| Radiographic loosening | 3 (33.3) | 3 (23.1) | 0.66 |
| Revision arthroplasty | 2 (22.2) | 1 (7.7) | 0.54 |
| Timing | |||
| Median (range) time to clinical failure (mo)b | 12 (0-213) | 12 (0-38) | 0.42 |
| Median (range) age of prosthesis (mo)c | 22 (5-250) | 14 (2-51) | 0.12 |
| No. (%) of patients with the following case definition: | |||
| Presence of sinus tractd | 2 (22.2) | 3 (23.1) | 1.00 |
| Visible purulence at implant sited | 5 (55.6) | 11 (84.6) | 0.18 |
| Acute inflammation in periprosthetic tissued | 7 (77.8) | 13 (100.0) | 0.16 |
| No. (%) of patients with the following laboratory findings: | |||
| Blood leukocyte count of >10 × 109/liter (n = 17) | 1/6e (16.7) | 3/11 (27.3) | 1.00 |
| ESR of >30 mm/h (n = 19)f | 1/7 (14.3) | 6/12 (50.0) | 0.17 |
| CRP concn of >1.0 mg/dl (n = 19)f | 2/7 (28.6) | 7/12 (58.3) | 0.35 |
| No. (%) of subjects with the following underlying joint disorder: | |||
| Osteoarthritis | 2/8 (25) | 7 (53.9) | 0.37 |
| Trauma | 4/8 (50) | 2 (15.4) | 0.15 |
| Rheumatoid arthritis | 0 (0) | 3 (23.1) | 0.26 |
| Avascular necrosis | 0 (0) | 0 (0) |
Includes a patient with both P. acnes and a Corynebacterium sp. growing from sonicate fluid and a patient with both P. acnes and a coagulase-negative Staphylococcus sp. growing from sonicate fluid.
Time between the last surgery at the implant site and the onset of symptoms.
Time between the last surgery at the implant site and removal of the implant.
Considered a diagnostic criterion for prosthetic shoulder infection.
Where the denominator is shown, data were not available for all study patients.
Cutoffs are from a previous report (21).