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 weeks: 7/12 (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 (dysfunction: 33.3 vs. 23.7; bother score: 32.8 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.