Septic arthritis. Specificity and sensitivity of culture and Gram stain. Figures quoted are from the Shmerling review,14 which relies on data from his previous study15
| SF culture | SF Gram stain | ||||
|---|---|---|---|---|---|
| Groups of infective agents | Prior antibiotics? | Sensitivity (%) | Specificity (%) | Sensitivity (%) | Specificity (%) |
| Non-gonococcal infections (mostly Staphylococcus aureus and streptococci) | No | 75–95 | 90 plus | 50–75 | Quite high |
| Yes | Much lower | Much lower | |||
| Gonococcal infections | No | 10–50 | <10 | ||