1. A lag screw extends through the first transverse passage of the intramedullary nail.

2. Cranial cutting out of the lag screw was only seen during postoperative mobilization.

3. The use of an additional lag screw produced a greater and significant (p<0,01) improvement.

4. Experimental study on treatment of acetabular anterior column fractures: Applyment of a minimally invasive percutaneous lag screw guide apparatus