CONTAMINATED RABBIT PATELLAR TENDON GRAFTS - IN-VIVO ANALYSIS OF DISINFECTING METHODS

In Part 1 of our study, 40 central-third bone-patellar tendon-bone gra fts were harvested from 20 adult California White rabbits under strict sterile conditions. Ten grafts were placed directly into a thioglycol ate broth, incubated, and subcultured; no growth was noted in any spec imen. The next 6 grafts were contaminated 20 seconds each with 2 diffe rent species of coagulase-negative staphylococci. Organisms were grown with cultures obtained from an operating room floor during anterior c ruciate ligament reconstruction. Marked growth of both species was not ed in all 6 grafts within 24 hours. A subsequent 3 series of 8 grafts each were harvested sterilely, contaminated as described above, and so aked in 1 of 3 solutions 30 minutes before culture. Both 10% povidone- iodine and a triple-antibiotic solution (gentamicin, clindamycin, poly myxin) were 100% ineffective as both organisms grew; 4% chlorhexidine gluconate effectively decontaminated 8 grafts in all cases. Part 2 inv olved contamination of harvested grafts with 5 common, virulent organi sms: Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Enterococcus faecalis. Elimination of all e xcept Klebsiella pneumoniae was successful with 4% chlorhexidine gluco nate alone for 8 grafts. Using a triple-antibiotic solution after chlo rhexidine gluconate in 6 grafts eliminated this organism also.