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Background: Methods of achieving tibiotalocalcaneal arthrodesis include intramedullary nailing, crossed lag screws, blade plates, and external fixation. While reports in the orthopaedic literature have compared the biomechanical properties of some of these fixation techniques, to our knowledge none has evaluated multiplanar external fixation. The purpose of this study was to compare the biomechanical properties of intramedullary nail fixation and external ring fixation for tibiotalocalcaneal arthrodesis., Materials and Methods: Tibiotalocalcaneal arthrodesis was performed on ten matched pairs of fresh-frozen human cadaveric legs. A ring fixator stabilized the arthrodesis in one leg from each pair and a 10 mm x 150 mm nail inserted retrograde across the subtalar and ankle joint stabilized the arthrodesis in the contralateral leg. The bending stiffness of the resulting constructs was quantified in plantarflexion, dorsiflexion, inversion, and eversion, and torsional stiffness was measured in internal and external rotation., Results: No difference in bending stiffness between the two constructs was identifiable in any of the four bending directions (p > 0.05). Torsional stiffness was approximately two-fold greater in both internal and external rotation in specimens with the ring fixator arthrodesis than in those with the intramedullary nail (p = 0.002)., Conclusion: The ring fixator provides a stiffer construct than a 10 mm x 150 mm intramedullary nail in torsion, but no difference in bending stiffness was demonstrable. Both techniques can provide satisfactory fixation; however, the ring fixator may better minimize rotational joint motion., Clinical Relevance: This study provides a basis for selecting an arthrodesis method that offers optimized fixation.

Background: Exposure of the posterolateral talar dome for osteochondral autograft transfer can be challenging. The purpose of this study is to compare surgical exposures for perpendicular access to the posterolateral talar dome using osteochondral transfer instrumentation., Materials and Methods: Five surgical approaches were performed on each of eight cadaveric ankles. The sequence was: (1) Anterolateral arthrotomy with ATFL release, (2) Anterolateral tibial osteotomy, (3) Fibular osteotomy with ATFL intact, (4) Fibular osteotomy with ATFL release, and (5) Fibular osteotomy with ATFL/CFL release. (ATFL repaired between 1 and 2). While maintaining the orientation of the harvester perpendicular to the talar dome articular surface, osteochondral plugs were harvested as far posteriorly as possible using a 6-mm harvester. Distances from the anterior talar articular surface to the posterior aspect of the recipient site were measured. Statistical analysis used ANOVA and Fisher post hoc tests., Results: Average AP exposure (mm) and percentage of AP talar dome dimensions exposed: (1) Anterolateral arthrotomy with ATFL release: 21.2 mm (43.3%), (2) Anterolateral tibial osteotomy: 33.7 mm (68.5%), (3) Fibular osteotomy(ATFL intact): 43.2 mm (87.8%), (4) Fibular osteotomy with ATFL release: 44.9 mm (91.2%), and (5) Fibular osteotomy with ATFL/CFL release: 46.6 mm (94.6%). All osteotomies provided greater exposure than anterolateral arthrotomy with ATFL release (p < 0.0001). A significant difference was obtained between each of the fibular osteotomies and tibial osteotomy (p < 0.0001). Differences between the fibular osteotomy approaches (3 to 5) were not significant., Conclusion: Fibular osteotomy provides the greatest perpendicular exposure to the posterolateral talar dome. Anterolateral tibial osteotomy provides greater exposure than arthrotomy alone., Clinical Relevance: This study provides a guide for surgical exposures to the posterolateral talar dome for osteochondral autograft transfer.