BMP-2 is commonly used in open tibia fractures at the time of definitive wound closure, and these wounds are prone to increased swelling and wound complications. The recent observation that IVAC decreases wound edema and increases oxygenation has led to their use in such cases. Used in conjunction, it is entirely possible that the negative pressure exerted by the IVAC can remove BMP-2 from surgical site and therefore decreases the effectiveness of BMP-2. We seek to determine if BMP-2 is present in effluent from the IVAC. If in this study the hypothesis is found to be wrong, and BMP-2 is found within the IVAC effluent, we are prepared to proceed with a follow-up study to quantify the BMP-2 removed by the IVAC.