Contaminated patellar tendon grafts: incidence of positive cultures and efficacy of an antibiotic solution soak--an in vitro study.

The incidence of positive cultures after contamination of sterile patellar tendon grafts in an operating room environment was studied in 10 specimens. The grafts were dropped on the floor for 3 min and then cultured. Six of the 10 grafts (60%) had a positive culture at 10 days. To test the efficacy of an antibiotic solution on cleansing contaminated grafts, 10 additional grafts were dropped on the floor for 3 min. Before the grafts were cultured they were soaked in a sterile saline solution containing bacitracin (33.33 U/ml) and polymyxin B (333.33 U/ml) for 15 min. Thirty percent of these grafts (3 of 10) cultured positive at 10 days. In each case the bacterial contaminant was found to be sensitive to one of the antibiotic agents used in the cleansing solution. The results of this study suggest that although soaking contaminated grafts in this antibiotic solution for 15 min may reduce the incidence of positive cultures, it still results in a 30% incidence of nonsterile grafts.