Decreased Reoperation Rate with ABMP in Foot and Ankle Fusions

Abstract

Category: Ankle; Hindfoot Introduction/Purpose: A nonunion is a challenging clinic problem following foot and ankle arthrodeses. There is great interest in orthobiologics as surgical adjuvants. The purpose of this study is to compare three orthobiologics (PDGF-B agonist [PDGF-B], allograft bone morphogenetic protein [ABMP], crushed cancellous allograft [CC]) to determine if there is a difference in union rates following foot and ankle arthrodeses. Methods: A retrospective review was conducted of 258 feet (255 patients) with minimum 3-month follow-up, undergoing arthrodesis by a single fellowship-trained foot and ankle orthopaedic surgeon from 2016-2022. Patients underwent ankle, pantalar, triple, subtalar (ST), midfoot, or talonavicular fusion. Data collected included demographics, medical history, orthobiologics used, postoperative complications, readmission and reoperation rates. 83 (34.0%) cases used PDGF-B with CC, 32 (13.1%) used solely ABMP, 66 (27.0%) used ABMP with CC, and 63 (25.8%) used solely 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 computed tomography (CT). Results: Of the 258 cases, the ST joint was most commonly fused (53.7%). Cases using ABMP had statistically significantly shorter mean time to fusion (ABMP=120.81 days, no ABMP=162.04 days). Patients treated with ABMP were also significantly less likely to undergo reoperation or removal of hardware. Between PDGF-B+CC and ABMP+CC groups, only reoperation rates differed significantly (PDGF-B+CC=26.5%, ABMP+CC=7.6%,). Multivariate regression modeling for time to fusion found ABMP usage to be the only statistically significant predictor of time to fusion, predicting patients will achieve fusion nearly 40.7 days quicker with the use of ABMP. Conclusion: Joints treated with PDGF-B and ABMP demonstrated equivalent fusion rates. Treatments using ABMP and CC achieved quicker time to fusion and lower rates of reoperation when compared to treatments using PDGF-B and CC.