Ankle, Hindfoot Study: Graft=Better Fusion

“How much graft is enough for a solid union?” asked researchers from The University of Rochester in New York, in their investigation of ankle and hindfoot arthritis. The research team, which included Judith Baumhauer, M.D., M.P.H., former president of The American Orthopaedic Foot & Ankle Society, used data from a prior clinical trial of grafting material (recombinant human platelet-derived growth factor-BB with beta-tricalcium phosphate [rhPDGF-BB/β-TCP] or autograft).

Dr. Baumhauer told OTW, “We were involved in a large multi-centered study looking at platelet derived growth factor as a bone graft substitute. The questions arose, ‘Who needs graft and does bone graft help fuse joints?’ This study examined the value of bone graft in fusion.

“We defined graft fill as ‘adequate’ if the material occupied ≥50% of the cross-sectional area of the fusion space on a computed tomography (CT) scan at the nine week mark. The joint was considered fused if there was an osseous bridging of ≥50% of each articulation on a CT scan at 24 weeks. We found that 472 (82%) of 573 joints had adequate graft fill; of those, 383 (81%) were successfully fused at 24 weeks compared with 21 (21%) of 101 joints without adequate graft fill.

“If the surfaces are not touching, they do not bridge bone and fusion does not occur. The graft helps fill these areas and promotes fusion. With the importance of graft highlighted, surgeons will hopefully consider using graft to have contact between the surfaces to promote healing.

“Based on this study, I use bone graft in the majority of my fusions. as there are always incongruities that occur when preparing the surfaces for the fusion.”