RESUMO
BACKGROUND: The optimal techniques for Lisfranc open reduction and internal fixation techniques remain debated. The purpose of the current study was to describe the joints involved in Lisfranc fixation and to determine if nonarticular transosseous internal fixation would be possible. METHODS: Twenty cadaver Lisfranc joints were dissected and the articular cartilage was quantified by calibrated digital imaging software. Utilizing CT data, a computational model of the foot was developed and the mean joint surface was mapped and nonarticular screw paths between bones was determined. RESULTS: For the medial-middle cuneiform (C1-C2) connection, 27.3% of the lateral face of C1 and 43.7% of the medial face of C2 was articular cartilage. Three variations of articular morphology were observed on C1 and 2 on C2. From the 3D models, it was determined that a joint-sparing, transosseous screw trajectory was possible between C1 and the second metatarsal and between C1 and C2. These screw paths were large enough to accommodate clinically useful screw diameters (>5 mm). The screw trajectories were roughly perpendicular to the long axis of the foot and take a plantar-medial to dorsal-lateral orientation. CONCLUSION: The articular surface of the Lisfranc joint was quantified for the first time and may be smaller than some surgeons realize. This study demonstrated the orientation required to minimize articular damage. CLINICAL RELEVANCE: The clinical significance of the current study was that a nonarticular screw trajectory was possible, and this information may help guide the placement of these screws.
