Evaluation of Midterm Results of the Panta Nail: An Active Compression Tibiotalocalcaneal Arthrodesis Device

Abstract

A tibiotalocalcaneal intramedullary rod is a powerful construct often reserved for difficult and salvage cases. The Panta Nail (Integra LifeSciences, Plainsboro, NJ) is a second-generation rod that offers active axial compression compared with previous rod designs. We characterized our experience with this device and identified factors associated with nonunion. We retrospectively identified 19 patients receiving the Panta Nail during a 4-year period with a mean follow-up period of 16 months. We used a consecutive series approach toward inclusion. Fusion, asymptomatic fibrous union, or nonunion was determined for each ankle and subtalar joint as the primary endpoint. Patients were grouped as follows: group A, successful outcome; group B, successful outcome after dynamization; group C, no successful outcome. Secondary data were tested for association with the probability of first-attempt fusion. The Panta Nail resulted in a first-attempt fusion rate of 65% at the ankle and subtalar joints. With implementation of dynamization (31% of cases) at an average of 28 weeks after insertion (groups A and B), the bony fusion rate was 88% and 77% at the ankle and subtalar joint, respectively. Inclusion of 3 asymptomatic fibrous unions with final visual analog scale scores <4 (1 ankle; 2 subtalar) as successful outcomes resulted in 94% and 88% success rates for the ankle and subtalar joints (groups A and B). Salvaged total ankle arthroplasties with the Panta Nail device as a subgroup had an 83% fusion rate, with a 50% dynamization rate. No predictors of nonunion were found. The Panta Nail is a second-generation tibiotalocalcaneal arthrodesis device capable of providing good success rates for fusion. Also, dynamization is an appropriate and frequent augmentation method.