Internal Fixation of Femoral Neck Fractures with Computer Assisted Surgery A Report on First Cases

摘要

In standard practice, osteosynthesis of femoral fractures is guided interactively by 2-D fluo-roscopy providing anteroposterior or axial projections. This approach leads to repetitive position changes of the C-arm with concomitant radiation exposure and may result in suboptimal positioning of implants. Fluo-roscopy-based navigation may offer a solution for these problems. The goal of this study was to evaluate the feasibility of fluoroscopy-based navigation in the treatment of intracapsular femoral neck fractures with a dynamic hip screw (DHS). Seven patients were treated with a 135deg DHS. Fluoroscopy-based navigation technique (Medivision, Oberdorf, Switzerland) was used for positioning the correct drill channel for the DHS. Therefore, the virtual position of an 8-mm noncannulated DHS reamerwas superimposed simultaneously on the anteroposterior and axial images. One procedure failed because the position of the virtual drill did not match the true situation. In this case, it was most likely that the dynamic reference base was moved relative to the proximal femur during the operation. This operation was continued under fluoro-scopic guidance. In one patient, the DHS was located in the cortex of the femoral head. In another patient the DHS was positioned not exactly in the center of the femoral neck, but slightly posterior. Mean system setup time was 10 minutes Conclusion: Fluoroscopy-based navigation is a feasible technique for the treatment of femoral neck fractures with a DHS. The initial results are encouraging. More intuitive techniques are currently being developed to enhance the application of navigation in routine trauma care.