Mechanical agitation and serial dilution: an option for anterior cruciate ligament graft sterilization

Contamination of tissue grafts can occur during anterior cruciate ligament reconstruction, necessitating decontamination. This study examined whether mechanical agitation and serial dilution provides greater bacterial eradication of experimentally contaminated bone-patellar tendon-bone grafts compared with antibiotic soak or pulsatile lavage. Forty bone-patellar tendon-bone grafts were contaminated with a bacterial suspension derived from operating room floor cultures. Four groups of specimens underwent immediate culture (control), antibiotic soak, pulsatile lavage, or mechanical agitation and serial dilution. The number of colony-forming units (CFU) for each group was statistically compared using t and chi-square tests. Each method of decontamination yielded a statistically significant reduction in CFU compared with the control. Analysis of positive versus negative cultures demonstrated a statistically significant difference between mechanical agitation and serial dilution compared with the other 2 methods. Mechanical agitation and serial dilution was the only method with 0 CFU and provided superior and consistent sterilization of experimentally contaminated grafts compared with antibiotic soak and pulsatile lavage.