RESUMEN
BACKGROUND: Tibiotalocalcaneal arthrodesis is commonly considered a salvage option for a variety of hindfoot disorders involving the ankle and subtalar joint mostly with concomitant deformity. Retrograde interlocking nailing represents one of the biomechanically most stable fixation modes after reduction of hindfoot geometry. The considerable complications, non-union and revision rates at a moderate outcome reported even with modern retrograde nails underscore the idea that the development of an optimized retrograde nail may be warranted. METHODS: A novel circular shaped nail was designed with a perfect fit to the reamed canal and the implant geometry which respects physiologic hindfoot anatomy and alignment. The present clinical series reports the experience and the clinical and radiographic outcomes after application of the implant in the first 30 consecutive patients. Assessments included validated versions of the AOFAS Ankle/Hindfoot Score and the Foot Function Index. RESULTS: Anatomical alignment was achieved and maintained in 29/30 cases with a single case of later loss of reduction due to a technical error which led to surgical reintervention two months after the index procedure. The overall union rate reached 93%. Two non-unions (one ankle, one subtalar joint) were observed without necessitating further surgery. Three superficial surgical site infections were registered which made a local flap coverage necessary in two patients due to local skin break-down. No deep infection occurred. There were 2 implant removals, one was not related to hindfoot nailing. At the time of follow-up, the AOFAS Ankle/Hindfoot Score was 57 (median) from a maximum of 86 points. The self-assessment via the Foot Function Index improved from preoperative 155 points to 62.5 postoperatively (median values, p<0.001, Wilcoxon test). CONCLUSION: On the basis of our results, which saw a high rate of successful fusion and patient satisfaction and where the hindfoot reduction was maintained until definite healing in the vast majority of cases, the novel circular arc nail represents a viable and safe option for tibiotalocalcaneal arthrodesis with a low complication rate.
