Optimal use of transmedullary support screws and fibular management in distal tibial fracture nailing based on a new biomechanical classification.

Abstract

Based on a novel simple frontal view classification, a comprehensive concept for systematic management of intramedullary fixation of distal tibial fractures is introduced. Even the usage of thin (unreamed) nails allows for anatomic reduction and stable fixation if applied in combination with transmedullary support (TMS) screws. Our classification system guides the placement of the TMS screw (medial or lateral) and suggests whether to fix the fibula or not. The fixation concept of the classification was applied to 67 distal tibial fracture cases. Patients were followed up until nail removal after at least 12 months. All fractures united. Besides 5 cases of slight external malrotation (<5 degrees) no axial malunion was found. Two infections were encountered, but both were treated effectively by exchange nailing, antibiotic therapy until wound healing and C-reactive protein normalization. Final functional assessment according to Olerud/Molander Score was 85 pts (100 pts. possible, range 50-100 pts). The stability we achieved even with single screw interlocking was high due to anatomic reduction with interfragmental compression in the lowest fracture line. In cases of fracture extension into the ankle joint, interfragmental compression screws were applied before nail insertion. In more comminuted fracture types additional screws are advisable. The frontal view classification has proven to be a reliable guideline for effective intramedullary fracture fixation by minimally invasive means, allowing for optimized soft tissue protection.