Synthetic polymer shows potential for bone hemostasis without increased infection risk

Rabbits treated with the polymer had a significantly lower incidence of osteomyelitis compared to those treated with bone wax.

A new polymer material designed for bone hemostasis during surgery may reduce the risk of surgical infection, according to results of an animal study published in Clinical Orthopaedics and Related Research.

Tadeusz Wellisz, MD, and colleagues at the University of Southern California, Los Angeles, and at the Medical University of South Carolina, Charleston, evaluated the effects of Ostene (Ceremed Inc.) on infection rates and bone healing in a rabbit tibial defect model. They compared the polymer to a group of animals treated with a beeswax-based hemostat (Bone Wax, Ethicon Inc.) and a control group that received no hemostatic agent, according to the study.

Ostene is a commercially available blend of water-soluble alkylene oxide copolymers.

The study involved 24 female New Zealand White rabbits, with eight animals assigned to each group.

After creating a tibial defect in each animal, researchers applied an inoculum of Staphylococcus aureus strain ATCC-29230.

Investigators found that animals treated with the water-soluble polymer and control animals had a significantly lower incidence of osteomyelitis (P < .004) and positive bone cultures (P < .02) compared to animals that received bone wax.

"The polymer had no effect on the infection rate and rate of positive cultures compared with controls (P < .001)," the authors wrote in the study.

At 4 weeks, all bone wax-treated animals showed radiographic evidence of moderate to severe osteomyelitis, including periosteal reaction and bone lysis. In addition, all animals in the bone wax group had the typical signs of bone infection on histologic examination, including the development of abscess lesions, cortical bone destruction and periosteal reaction, according to the study.

The bone marrow structure was also destroyed in all bone wax-treated specimens, the authors noted.

"By comparison, six of the eight animals had normal radiographs in the polymer and the control groups; the other two animals in each group had radiographic evidence of osteomyelitis together with typical histologic signs of bone infection, including abscesses and destruction of bone and marrow structures," they wrote.

Additionally, all cultures from bone segments of the bone wax-treated group tested positive for the S. aureus strain. In contrast, only cultures from animals with radiographic evidence of osteomyelitis were positive in the polymer and control groups, and one animal of the six with normal radiographs in each group had a positive culture, according to the study.

"The use of the water-soluble polymer did not affect bone healing compared with controls (P < .001). All of the cortical defects in the animals without radiographic evidence of infection had histologic evidence of bone healing," the authors wrote.

For more information:
Wellisz T, An YH, Wen X, et al. Infection rates and healing using bone wax and a soluble polymer material. Clin Orthop Relat Res. 2008;466:481-486.