rhBMP-2 Versus Autograft in Critical Size Tibial Defects

Open tibia fractures have a 15% or higher rate of not healing. Those fractures which do not heal are typically treated with bone from the hip (iliac crest autograft; or ICBG). The use of ICBG bone with the treatment of delayed unions/non-unions with critical defect, although successful, has its drawbacks. The bone graft sources are limited and the procedure is associated with additional operating room time plus a second incision with increased risk of infection, post operative pain and increased hospital stay. The purpose of this study is to determine if Rh-BMP2, a new bone graft substitute, is at least as effective as using bone from the hip (autograft) to help promote healing of open, tibia (shin bone) fractures. Research Questions: Primary: What is the relative effect of rhBMP-2 versus autogenous ICBG on rates of union in patients with critical size defects following tibial shaft fractures? Null hypothesis #1: rhBMP-2 has the same union rate when used in critical-sized defects as does ICBG. Secondary: What is the relative effect of rhBMP-2 versus autogenous ICBG on infection rates in patients with nonunion or critical size defects following tibial shaft fractures? Null hypothesis #2: The infection rate in open tibias with critical-sized defects treated with rhBMP-2 and autogenous ICBG are the same. What is the economic impact of the use of Rh-BMP 2 for tibial fractures with critical sized defects? Null hypothesis #3: There will be no difference in the economic cost of the treatment of critical sized defects using the RhBMP-2 versus iliac crest bone graft.