A Randomized Controlled Trial Comparing rhBMP-2/Absorbable Collagen Sponge Versus Autograft for the Treatment of Tibia Fractures With Critical Size Defects

OBJECTIVES:To compare radiographic union of tibia fractures with bone defects treated with recombinant bone morphogenetic protein‐2 (rhBMP‐2) with allograft to autogenous iliac crest bone graft (ICBG). DESIGN:FDA-regulated multicenter randomized trial. SETTING:Sixteen US trauma centers. PATIENTS/PARTICIPANTS:Thirty patients (18–65 years of age) with Type II, IIIA, or IIIB open tibia fracture and bone defect treated with an intramedullary nail. INTERVENTION:rhBMP-2 (n = 16) versus ICBG (n = 14). MAIN OUTCOME MEASUREMENTS:Radiographic union within 52 weeks. Secondary outcomes included clinical healing, patient-reported function, major complications, and treatment cost. Equivalence was evaluated by testing whether a 90% two‐sided confidence interval for the difference in the probability of radiographic union between rhBMP‐2 or ICBG is contained with the interval [220% to +20%]. A post hoc Bayesian analysis, using data from a previous trial, was also conducted. RESULTS:Twenty-three patients had union data at 52 weeks7/12 (58.3%) rhBMP-2 were radiographically united compared with 9/11 (81.8%) ICBG, resulting in a treatment difference of −0.23 (90% CI−0.55 to 0.10). Patients treated with rhBMP-2 had lower rates of clinical healing at 52 weeks (27% vs. 54%), higher mean Short Musculoskeletal Function Assessment scores (dysfunction33.3 vs. 23.7; bother score32.8 vs. 21.4) and experienced more complications (5 vs. 3). Mean treatment cost for rhBMP-2 was estimated at $14,155 versus $9086 for ICBG. CONCLUSIONS:These data do not provide sufficient evidence to conclude that ICBG and rhBMP-2 are equivalent regarding radiographic union. LEVEL OF EVIDENCE:Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.