A prospective pilot study of B2A-coated ceramic granules (Amplex) compared to autograft for ankle and hindfoot arthrodesis.

BACKGROUND To reduce fusion nonunion, autogenous bone graft is often incorporated into foot and ankle fusion procedures. B2A peptide-coated ceramic granules, with encouraging results in pilot studies of transforaminal lumbar interbody fusion, were here reformulated into Amplex with a coating concentration of 225 μg B2A/cm(3) ceramic granules (B2A-granule) with the goal of eliminating autogenous bone graft in foot and ankle arthrodesis. The purpose of this study was to perform a multicenter prospective randomized pilot clinical trial designed to compare the safety and effectiveness of B2A-granule to autogenous bone graft in patients undergoing foot and ankle arthrodesis surgery. METHODS This study was a multicenter, prospective, randomized, pilot clinical trial designed to compare safety and effectiveness of B2A-granule to autogenous bone graft in patients undergoing foot and ankle arthrodesis surgery. Twenty-four patients were enrolled and randomized (1:1) into 2 groups: autogenous bone graft control and B2A-granule. Primary outcome measures at 6 months (with follow-up at 9 and 12 months) included radiographic fusion assessed by computerized tomography and Ankle Osteoarthritis Scale scores for pain and disability. RESULTS Radiographic fusion success rates were similar in both groups (100% in the B2A-granule group, 92% autograft). Both the B2A-granule group and the autograft group had improvements in the pain and disability scores over the course of the study. Graft harvest-site pain affected only autograft-treated patients. There were no adverse events attributed to the graft material in either the B2A-granule or autograft group. CONCLUSION The results of this pilot study are supportive of a larger clinical trial to assess the safety and efficacy of B2A-granule as a bone graft substitute in foot and ankle fusions. LEVEL OF EVIDENCE Level II, prospective comparative study.