A standardized fracture reduction model for long bones--implication and evaluation in the femur.

Fractures of the femoral bone are frequent injuries with a wide range of affected individuals. New treatment strategies and technologies are being explored permanently. Their quality is biomechanically judged by the accuracy of the anatomical reduction. Malalignment of the fragments would have an eminent impact on the overall outcome and rehabilitation. To establish a method for investigations of the reduction results of femoral fractures, we developed a model, using a navigation system for taking measurement. The dynamic reference bases (DRBs) were mounted to the intact femoral bone and registered as the reference position. A special construction allowed removal and reattachment of the DRBs without provoking change in the DRB-bone system. The model was evaluated in its constancy. Translational deviations remained below 0.9 mm and rotational deviations below 0.3° after 40 repetitive reattachments. The model could prove to be valid and reliable. An application in long-bone trauma research is reasonable.