Background: Recombinant human bone morphogenetic protein-2 (rhBMP-2) improves healing of open tibial fractures treated with unreamed intramedullary nail fixation. We evaluated the use of rhBMP-2 in the treatment of acute open tibial fractures treated with reamed intramedullary nail fixation.
Methods: Patients were randomly assigned (1:1) to receive the standard of care consisting of intramedullary nail fixation and routine soft-tissue management (the SOC group) or the standard of care plus an absorbable collagen sponge implant containing 1.5 mg/mL of rhBMP-2 (total, 12.0 mg) (the rhBMP-2/ACS group). Randomization was stratified by fracture severity. The absorbable collagen sponge was placed over the fracture at wound closure. The primary efficacy end point was the proportion of subjects with a healed fracture as demonstrated by radiographic and clinical assessment thirteen and twenty weeks after definitive wound closure.
Results: Two hundred and seventy-seven patients were randomized and were the subjects of the intent-to-treat analysis. Thirteen percent of the fractures were Gustilo-Anderson Type IIIB. The proportions of patients with fracture-healing were 60% and 48% at week 13 (p = 0.0541) and 68% and 67% at week 20 in the rhBMP-2/ACS and SOC groups, respectively. Twelve percent of the subjects underwent secondary procedures in each group; more invasive procedures (e.g., exchange nailing) accounted for 30% of the procedures in the rhBMP-2/ACS group and 57% in the SOC group (p = 0.1271). Infection was seen in twenty-seven (19%) of the patients in the rhBMP-2/ACS group and fifteen (11%) in the SOC group (p = 0.0645; difference in infection risk = 0.09 [95% confidence interval, 0.0 to 0.17]). The adverse event incidence was otherwise similar between the treatment groups.
Conclusions: The healing of open tibial fractures treated with reamed intramedullary nail fixation was not significantly accelerated by the addition of an absorbable collagen sponge containing rhBMP-2.