Stability of femoral neck osteotomies fixed by von Bahr screws or by compression hip screw.

Subcapital cadaveric femoral neck osteotomies were internally fixed either by a compression hip screw and a lag screw or by two von Bahr screws. The specimens were then subjected to mechanical testing. Continuously increasing axial compression loads were applied on the femoral head until failure and simultaneously the displacement of the osteotomies was measured. With loads up to 2 kN (about 3 times the body weight) no differences were found between the two groups in the displacement of the osteotomies.