Recombinant human bone morphogenetic protein-2: a randomized trial in open tibial fractures treated with reamed nail fixation.

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.

Recombinant human BMP-2 and allograft compared with autogenous bone graft for reconstruction of diaphyseal tibial fractures with cortical defects. A randomized, controlled trial.

BACKGROUND: Currently, the treatment of diaphyseal tibial fractures associated with substantial bone loss often involves autogenous bone-grafting as part of a staged reconstruction. Although this technique results in high healing rates, the donor-site morbidity and potentially limited supply of suitable autogenous bone in some patients are commonly recognized drawbacks. The purpose of the present study was to investigate the benefit and safety of the osteoinductive protein recombinant human bone morphogenetic protein-2 (rhBMP-2) when implanted on an absorbable collagen sponge in combination with freeze-dried cancellous allograft. METHODS: Adult patients with a tibial diaphyseal fracture and a residual cortical defect were randomly assigned to receive either autogenous bone graft or allograft (cancellous bone chips) for staged reconstruction of the tibial defect. Patients in the allograft group also received an onlay application of rhBMP-2 on an absorbable collagen sponge. The clinical evaluation of fracture-healing included an assessment of pain with full weight-bearing and fracture-site tenderness. The Short Musculoskeletal Function Assessment (SMFA) was administered before and after treatment. Radiographs were used to document union, the presence of extracortical bridging callus, and incorporation of the bone-graft material. RESULTS: Fifteen patients were enrolled in each group. The mean length of the defect was 4 cm (range, 1 to 7 cm). Ten patients in the autograft group and thirteen patients in the rhBMP-2/allograft group had healing without further intervention. The mean estimated blood loss was significantly less in the rhBMP-2/allograft group. Improvement in the SMFA scores was comparable between the groups. No patient in the rhBMP-2/allograft group had development of antibodies to BMP-2; one patient had development of transient antibodies to bovine type-I collagen. CONCLUSIONS: The present study suggests that rhBMP-2/allograft is safe and as effective as traditional autogenous bone-grafting for the treatment of tibial fractures associated with extensive traumatic diaphyseal bone loss. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions to Authors for a complete description of levels of evidence.