Der Unfallchirurg
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Biomechanical studies were carried out to assess the function and performance of intramedullary (IM) nails for femoral fractures. An appropriately sized femoral IM nail with a radius of curvature of about 109 cm would most closely match the anterior bow of most human femora. A number of parameters can interact to result in bursting of the femur during insertion of the nail. ⋯ Slotted IM nail/femur constructs have only about 3% the rigidity of the intact femur in torsion, while an unslotted (closed) section implant produces constructs with about 50% the rigidity. The distal locking bolts increase the torsional rigidity and maximum axial load capacity of the construct, and reduce the potential for shortening and the residual deformation upon release of a torsional load. Two distal bolts reduce the toggle of the nail in the femoral shaft.(ABSTRACT TRUNCATED AT 250 WORDS)