3D Printed Titanium Wedges for Distraction Arthrodesis of the Subtalar Joint

Abstract

Category: Hindfoot Introduction/Purpose: Distraction arthrodesis of the subtalar joint is performed to restore height and correct deformity in the case of subtalar joint arthrosis, malalignment of the rear foot, calcaneal fracture, or other pathologies. Historically, autograft or allograft bone blocks were used to restore natural alignment and improve hindfoot function. Although successful use has been reported, complications associated with donor site morbidity and size limitation for autograft, as well as additional complications including nonunion, graft collapse, and loss of alignment are common. Recently, innovative advancements have enabled the use of 3D printed porous titanium implants for use, improving the union rates and reduced risk of subsidence and graft collapse. Methods: 6 patients with subtalar collapse and anterior ankle impingement were indicated for distraction subtalar arthrodesis. Surgery was performed with a lateral approach for the distraction arthrodesis using an off the shelf 3D printed subtalar wedge and a nitinol pseudoelastic fusion rod for stabilization and fixation. Patients were followed 6 months post op for fusion and alignment. Fusion was confirmed at 3 months with CT scans and alignment was monitored with weightbearing ankle X-rays. Results: 3D wedge incorporation and sustained correction of height and alignment was maintained over time at the subtalar joint. There were no nonunions, 2 patients reports skin healing issues due to tension on the skin with wound closure. These healed with local wound care. Improvement in preoperative to postoperative tibiotalar sagittal plane alignment was observed in all patients. Conclusion: The use of a 3D printed titanium wedge for distraction Arthrodesis of the subtalar joint is a safe procedure and useful procedure in short-term follow-up. This procedure does provide improvement in the patients alignment and fusion occurs with in 3 months of surgery.