Use of bone morphogenetic protein-2 for adult spinal deformity.

STUDY

DESIGN

Prospective, single-center, nonblinded clinical and radiographic analysis of consecutive adult deformity patients treated with recombinant human bone morphogenetic protein-2 (rhBMP-2) without iliac or rib bone graft supplementation.

OBJECTIVES

To determine the ability of rhBMP-2 to achieve both anterior and posterior spinal fusion in patients undergoing multilevel fusions for adult spinal deformity.

SUMMARY OF BACKGROUND DATA: The literature concerning one-level anterior fusions, and potentially one-level posterior fusions, using rhBMP-2 has demonstrated clinical efficacy. No published data exist on the use of rhBMP-2 in multilevel spine fusions.

METHODS

Prospective analysis of patients treated with rhBMP-2 in multilevel anterior and posterior fusions with a minimum 1-year follow-up. There were a total of 95 patient samples (70 total patients; 25 patients had rhBMP-2 used circumferentially): 46 anterior fusions (Group 1), 41 posterior fusions (Group 2), and 8 patients were "compassionate use" fusions (Group 3). In the anterior fusion group (n = 46), mean rhBMP-2/level was 10.8 mg in titanium mesh cages without any bone graft or other substance. The posterior fusion group had only local bone graft, no harvested rib or iliac bone graft (n = 41). The mean rhBMP-2/level was 13.7 mg. The "compassionate use" group (n = 8 patients) consisted of patients who had prior surgeries, prior iliac harvesting, and substantial comorbidities and therefore a higher concentration and different carrier was used. No local bone graft, no harvested bone was used. The mean rhBMP-2/level was 28.6 mg. The median dose was 40 mg for Group 3.

RESULTS

For the anterior fusion group (n = 46), operative levels were deemed fused in 89 of the 93 (96%) levels. For the posterior fusion group (n = 41), a solid fusion was assessed in 110 of the 118 (93%) operative levels. For the "compassionate-use" patients, the overall fusion rate was 100% (52 of 52 operative levels).

CONCLUSIONS

With the use of rhBMP-2, a high rate of apparent fusion was observed for anterior (96%) and posterior (93%) fusions in adult spinal deformity patients. Use of rhBMP-2 results in a promising early fusion rate without the graft harvest site morbidity.