Margaretten ME, Kohlwes J, Moore D, Bent S. JAMA. 2007Apr.4;297(13):1478–88.
This systematic overview from the excellent JAMA series reviewed the relatively weak evidence regarding assessment of patients with suspected septic arthritis. JC attendees found the odds ratios for clinical findings to be useful (high risk - age 80, recent joint surgery, joint prosthesis, joint pain; insensitive – fever) and the findings for synovial fluid to be informative (helpful - WBC, PMNs; not helpful – glucose, protein, LDH, gram stain). A low synovial WBC count cannot r/o septic arthritis if PMNs > 90%.