Local antibiotic delivery with demineralized bone matrix.

A method of care for these infected nonunions is prolonged intravenous systemic antibiotic treatment and implantation of methyl methacrylate antibiotic carrier beads to delivery high local doses of antibiotics. This method requires a second surgery to remove the beads once the infection has cleared. Recent studies have investigated the use of biodegradable materials that have been impregnated with antibiotics as tools to treat bone infections. In the present study, human demineralized bone matrix (DBM) was investigated for its ability to be loaded with an antibiotic. The data presented herein demonstrates that this osteoinductive and biodegradable material can be loaded with gentamicin and release clinically relevant levels of the drug for at least 13 days in vitro. This study also demonstrates that the antibiotic loaded onto the graft has no adverse effects on the osteoinductive nature of the DBM as measured in vitro and in vivo. This bone void filler may represent a promising option for local antibiotic delivery in orthopedic applications.

Osteoconductivity and osteoinductivity of Puros(R) DBM putty.

Bone graft substitutes have been developed due to the limited supply and morbidity associated with using autogenous graft material. Allogeneic demineralized bone matrix (DBM) has been used extensively as a clinical graft material because of its inherent osteoinductive and osteoconductive properties. Differential enhancement of these properties may optimize the performance of these products for various orthopedic and craniofacial applications. Commercially available bone paste products consist of formulations that combine DBM with a carrier to facilitate handling and containment. In the present study, we present results of a comprehensive in vitro and in vivo characterization of a 100% human DBM putty product, Puros DBM Putty. Results indicate the DBM particles are completely dispersed in the putty. Data are presented showing the porosity of and cell attachment to Puros DBM Putty, thereby demonstrating the osteoconductive properties of this DBM. Puros DBM Putty was also shown to be osteoinductive in the rat ectopic pouch model. We demonstrate here for the first time that Puros DBM Putty maintains its activity to markedly stimulate or induce bone formation over the entire period of its shelf life. Taken together, these data demonstrate that the 100% human allograft derived Puros DBM Putty could be an effective bone graft substitute.

Local antibiotic delivery with bovine cancellous chips.

Infected bone defects and osteomyelitis are encountered frequently in trauma cases. Currently, the standard of care for osteomyelitis cases is prolonged systemic antibiotic therapy and implantation of antibiotic carrier beads. However, this method requires a secondary surgery to remove the beads after the infection has cleared. In the present study a common bone void filler was investigated for its ability to be infused with an antibiotic. This study demonstrates that the xenograft material tested can be loaded with gentamicin and release clinically relevant levels of the drug for at least 14 days in vitro allowing for the inhibition of bacterial growth on the graft. This study also demonstrates that the levels of gentamicin released did not have an adverse effect on primary osteoblast cell proliferation or ability to generate alkaline phosphatase. This bone void filler may represent a viable alternative to current methods of local antibiotic delivery in orthopedic applications.