Abstract
The photoelastic technique was applied to acrylic models of unstable trochanteric fractures. Model osteosynthesis was performed on nail-plates with different angles. An increase of the angle between the nail and plate was shown to reduce the shear force between those two components considerably. From mechanical considerations it is recommended that a steep placement of the nail-plate is advantageous in osteosynthesis of unstable trochanteric fractures without medial support.