Reoperation Rate with Viable Allogenic Bone Scaffold in Foot and Ankle Fusions

Research Type: Level 3 - Retrospective cohort study, Case-control study, Meta-analysis of Level 3 studies Introduction/Purpose: Nonunion is a challenging problem following foot and ankle arthrodeses. The purpose of this study is to compare Viable Allogenic Bone Scaffold (VABS) to other orthobiologics (PDGF-B agonist [PDGF-B], allograft bone morphogenetic protein [ABMP], crushed cancellous allograft [CC]) to determine any differences in union rates following foot and ankle arthrodeses. Methods: A retrospective review of 390 feet (373 patients) with a minimum 3-month follow-up was conducted. undergoing arthrodesis by one of two fellowship-trained foot and ankle orthopaedic surgeons from 2016-2023. Procedures included ankle, pantalar, triple, subtalar (ST), midfoot, and talonavicular fusion performed by two fellowship-trained foot and ankle orthopaedic surgeons (2016–2023). 42 cases used no biologic, 91 used PDGF-B with CC, 43 used solely ABMP, 95 used ABMP with CC, 66 used solely CC, 42 used V92 only, and 11 used V92 with CC. Union was defined as bridging bone on three joint quadrants on AP and lateral radiographs, or greater than 50% bridging bone of the joint space on CT. The overall cohort was majority female (54.4%) with mean age 56.71 (range 16-82) years, mean BMI 32.24 (range 17.1-62.7) kg/m2 and mean follow-up duration 1.13 (range 0.25-5.96) years. Results: The ST joint was most commonly fused (219 cases, 56.2%). VABS+CC cases had lower BMI and fewer cardiac comorbidities. The only significant difference among outcomes was 90-day readmission, with higher rates in patients receiving no biologic. VABS-treated cases had lower reoperation rates (5.7% vs. 17.5%) and lower rates of hardware removal (3.8% vs. 16.0%). No differences in union rates or time to union were observed. Conclusion: In foot and ankle arthrodeses treated with VABS, there were equivalent rates and time to fusion when compared to other orthobiologics. Arthrodesis performed using V92 demonstrated statistically significantly lower rates of reoperation when compared to treatments using other orthobiologics.