Charcot-Marie-Tooth Disease as a Risk Factor for Periprosthetic Fractures in Tibiotalocalcaneal Fusion With Intramedullary Nailing.

Introduction The treatment for severe fixed hindfoot osteoarthritis secondary to Charcot-Marie-Tooth disease (CMT) is tibiotalocalcaneal (TTC) arthrodesis. In our centre, we have noticed a disproportionate rate of periprosthetic fractures in CMT patients following TTC arthrodesis with retrograde hindfoot nailing. The aim of this study was to test this hypothesis by evaluating our local cohort of TTC arthrodesis with retrograde hindfoot nailing. Methods A retrospective review of patients who had TTC arthrodesis with intramedullary nailing was conducted over a seven-year period. Results There were 45 patients (30 male, 15 female) in our cohort. Forty-one patients achieved radiological and clinical fusion of their TTC arthrodesis. All three patients who had CMT sustained periprosthetic fracture at the tip of the nail at an average of four (range: 2.5-6) months from index operation. In comparison, no patients in the rest of the cohort sustained periprosthetic fractures. The nail position of the patients with CMT was central in both planes in all three patients. None of the patients with CMT had abutment of the cortex on either plane. Conclusion We found that there was a disproportionate rate of periprosthetic fractures in CMT patients in our cohort of TTC arthrodesis with retrograde hindfoot nailing. This suggests that CMT is a significant risk factor. The authors propose a longer nail to reduce the lever arm, with a long period of protected weight bearing till union, followed by consideration of elective removal of the nail to prevent this phenomenon from occurring.