Comparing Rates of Fusion and Time to Fusion in A Viable Cellular Allograft vs Autograft in Forefoot, Midfoot, and Hindfoot Fusions

Abstract

Category: Other; Ankle Arthritis; Hindfoot; Midfoot/Forefoot Introduction/Purpose: Allograft is routinely used to enhance bone healing in foot and ankle surgery. One allograft in particular employs viable cells and bone scaffolding in a gel base. There is little evidence that compares how this material effects rate of fusion (ROF) and time to fusion (TTF) when compared to autograft in routine forefoot, midfoot, and hindfoot fusions. Our study investigates the use of a viable cellular allograft and its effect on these two variables in a population of patients undergoing fusions in the foot and ankle. Methods: A retrospective review was conducted over a five-year span of patients undergoing fusions in the foot and ankle where the cellular allograft was used. We compared the ROF and TTF between the following three graft groups: cellular allograft alone, autograft alone, and combined allograft + autograft. Data was retrieved from the patients' electronic medical record and TTF was recorded as the time, in days, it took for a solid radiographic fusion to form. Secondary variables collected included etiology of disease (post-traumatic, inflammatory, or diabetic arthropathy) and also analyzed for effect on ROF and TTF. Results: Two hundred and twenty-five patients underwent a fusion in the foot or ankle over a five-year period. Autograft alone was used in 101 patients, the cellular allograft alone was used in 88 patients, and a combination of autograft and the cellular allograft was used in 36 patients. Each group were similar in their comorbid conditions and demographics. The ROF of the autograft only group was 88% (89/101), compared to the cellular allograft group's ROF of 89% (78/88), and the combination graft group's ROF of 75% (27/36). The average TTF between each group varied slightly, with the cellular allograft group fusing the fastest at 86, followed by the autograft alone group at 97 days, and the combined group at 112 days. Conclusion: Our study investigated the use of a viable cellular allograft and its effect on ROF and TTF compared to autograft alone and autograft combined with said cellular allograft. We found no significant difference in ROF between autograft alone and the cellular allograft alone but did find a significant difference in ROF for the combined group resulting in lower rate of fusion. Additionally, use of the cellular allograft resulted in fastest time to fusion compared to autograft alone or a combination of the graft types.