Purpose: To determine the rate of antibiotic elution from tobramycin-impregnated ProOsteon (Interpore) and Collagraft (Zimmer). Methods: Five samples of Collagraft and ProOsteon were impregnated with a solution containing 1.2 g of tobramycin and 10 ml of sterile water. The samples were then allowed to dry overnight. These samples were stored at 37°C in separate test tubes containing phosphate buffered saline (PBS). The solution in each test tube was removed with a pipette at hours 3, 6, 9 and 12 and days 1, 2, 3, 5, 7, 9, 11 and 13. The PBS was then replaced. The pipetted solution was sent for laboratory quantification and also used in a bioassay to determine antibiotic level. To serve as a control, two additional samples of each bone graft that were not impregnated with antibiotic were placed in separate test tubes and subjected to the same protocol. Results: The antibiotic elution rate for both ProOsteon and Collagraft was high at 3 hours [5362 and 4875 μg/ml on day 3 (3.1 μg/ml) for the Collagraft and day 7 (3.7 μg/ml) for the ProOsteon]. Effective intravenous tobramycin level is considered to be 4–6 μg/ml. Conclusion: Bone graft substitute can be used as a delivery vehicle for tobramycin. In addition, antibiotic-impregnated synthetic bone graft may potentially fill a dead space or cavitary defect without the need for large autologous grafts and does not require later removal.
Radiological Analysis of Gentamicin Eluting Synthetic Bone Graft Substitute Used in the Management of Patients With Traumatic Bone Voids
