Revision shoulder arthroplasty with positive intraoperative cultures: the value of preoperative studies and intraoperative histology.

Currently, there are no reported results of patients without overt infection who had a positive intraoperative culture during revision shoulder arthroplasty. We therefore reviewed the intraoperative and preoperative investigations as well as the postoperative course of these patients who had positive intraoperative cultures. We reviewed the results of 75 shoulders without overt infection that underwent revision shoulder arthroplasty at our institution between January 1, 1974 and December 31, 2002 who had positive intraoperative cultures. Preoperatively, the results of 67 (93%) of 72 white-blood-cell counts were negative, 64 (91%) of 70 polymorphonuclear percentage distributions were negative, and 36 (86%) of 42 samples of erythrocyte sedimentation rate were negative. C-reactive protein concentration was measured in 16 patients, of which 12 (75%) had negative results. Results of intraoperative histologic evaluations were negative in 67 (92%) of 73 patients. The most common pathogen cultured was Propionibacterium acnes in 45 of 75, followed by Staphylococcus epidermidis in 10 of 75. Another operation was necessary in 10 (13%) of 75 shoulders to decrease pain or improve function. The mean time to re-revision was 2.5 years. The data from this study suggest that there are no good preoperative or intraoperative investigations to detect who will have a positive intraoperative culture at the time of revision shoulder arthroplasty.