The effects of a soluble polymer and bone wax on sternal healing in an animal model

Purpose. This study compares the effects of a soluble polymer hemostatic material and bone wax on sternal bone healing. Description. Median sternotomies were performed on 20 New Zealand White rabbits, and sufficient polymer (Ostene; Ceremed Inc, Los Angeles CA) or bone wax (Bone Wax; Ethicon Inc, Somerville, NJ) was applied to achieve bone hemostasis. After 6 weeks, sternal healing was assessed using roentgenograms, histology, and mechanical strength testing. Evaluation. Roentgenograms revealed normal bone healing in the polymer-treated group and nonunion in the bone wax group. Histology showed normal bone healing in the polymer group, with fibrotic scar tissue and the absence of new bone formation in the bone wax group. Mechanical strength testing showed that polymer-treated sternal segments were twice as strong as those treated with bone wax. They had a significantly higher flexural strength (2.53 +/- 0.43 vs. 1.29 +/- 0.37 megapascal [MPa]; p < 0.001) and Young's modulus ( 0.315 +/- 0.056 vs 0.146 +/- 0.031 MPa; p < 0.001). Conclusions. The application of the polymer hemostatic material to the sternum resulted in significantly stronger union compared with the use of bone wax. (c) 2008 by The Society of Thoracic Surgeons.