Measurement of the principal compressive trabeculae in the midcoronal plane of proximal femur and its significance in lag screw fixation

For the elderly, the PCT is the main load-bearing structure between the femoral head and neck, and should be regarded as the target for lag screw fixation. Both the middle and lower PCT can provide ideal screw-tracts for lag screw fixation. In order to obtain the maximum anchoring strength, the upper positioned lag screw should be placed deep, while the lower positioned should be placed shallow.