OssDsign Catalyst® Performance in a Revision Subtalar Arthrodesis

Subtalar arthrodesis presents a challenge to the surgeon due to the complexity of joint anatomy and a limited blood supply, which can slow healing. In revision procedures these challenges are even more prevalent. A 72-year-old male patient presented with a failed subtalar arthrodesis performed two years prior with constant pain (VAS 7/10) and antalgic gait, with tenderness at the subtalar joint. The revision surgery included the replacement of the original screws with larger fully threaded screws. A silicate enriched (5.8wt% silicon) calcium phosphate bone graft substitute (OssDsign Catalyst®) was developed recently with nanoarchitecture and site-specific silicate substitution to mimic the structure of natural bone and follow the healing pathways more commonly associated with autograft or biologics, including both intramembranous and endochondral ossification. Five ccs of Catalyst bone graft substitute were mixed with a small amount of calcaneal autograft thus completing the revised construct. X-Ray and CT Scans at 3-month follow-up showed intact and well positioned screws and evidence of early and complete consolidation of the bone graft. The patient returned to full weight bearing and was free of pain, walking with regular shoes. There were no intraoperative or post-operative complications. The choice of larger fully threaded screws and selection of a synthetic bone graft highly suited for challenging environments with limited blood supply (endochondral ossification), allowed the surgeon to achieve unexpected early arthrodesis and excellent clinical outcome.