The synergistic effect of autograft and BMP-7 in the treatment of atrophic nonunions

Abstract

Combining autologous bone graft and recombinant human bone morphogenetic protein-7 (BMP-7) to treat long-bone fracture aseptic atrophic nonunions theoretically could promote bone healing at higher rates than each of these grafting agents separately. We retrospectively reviewed prospectively collected data on patient general characteristics, clinical outcomes, and complications over 3 years to determine the healing rates and the incidence of complications and adverse events of this "graft expansion rationale." There were 45 patients (32 male) with a median age of 43 years (range, 19-76 years). Minimum followup was 12 months (mean, 24.5 months; range, 12-65 months). There were seven humeral, 19 femoral, and 19 tibial nonunions. The median number of prior operations was two (range, 1-7). All fractures united. Clinical and radiographic union occurred within a median of 5 months (range, 3-14 months) and 6 months (range, 4-16 months), respectively. Thirty-nine (87%) patients returned to their preinjury occupation at a mean of 4.2 months (range, 3-6 months). The median visual analog scale pain score was 0.9 (range, 0-2.8; maximum 10), and the median functional score was 86 (range, 67-95; maximum 100) at the final followup. BMP-7 as a bone-stimulating agent combined with conventional autograft resulted in a nonunion healing rate of 100% in these 45 patients.

Level of evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Fig. 1A–D

Images illustrate the case of Patient 43 (Table 1) before combined treatment with autologous bone graft (ABG) and bone morphogenetic protein-7 (BMP-7). (A) Postinjury anteroposterior and (B) lateral radiographs show an open Grade IIIb tibial fracture. (C) A postsurgery anteroposterior radiograph shows the fracture after initial fixation (intramedullary nailing). (D) An anteroposterior radiograph taken 8 months postsurgery shows the evident atrophic nonunion.

Fig. 2A–D

Intraoperative photographs show the application of the combination of autologous bone graft (ABG) with bone morphogenetic protein-7 (BMP-7) at the site of the tibial nonunion (8 months after the original fracture fixation) in Patient 43 (Table 1). Photographs show (A–B) the nonunion site with the intramedullary nailing (IMN) in situ after the débridement of the nonunion tissues, (C) application of the BMP-7 putty at the nonunion site, and (D) application of the ABG at the nonunion site.

Fig. 3A–B

Images illustrate the case of Patient 43 (Table 1) after combined treatment with autologous bone graft (ABG) and bone morphogenetic protein-7 (BMP-7). (A) An anteroposterior radiograph taken on the first postoperative day after the combined grafting of the tibial nonunion shows the grafting material (ABG and BMP-7) as applied at the nonunion site. (B) An anteroposterior radiograph taken 5 months after the combined ABG and BMP-7 grafting shows the healed tibial nonunion.