[Fixation of humeral head fractures with antegrade intramedullary nailing]

The new method of antegrade intramedullary fixation of humeral head fractures is based on a straight proximal humeral nail with special head fixation screws and conventional interlocking screws at the proximal end of the shaft fragment leaving an axillary nerve shelter space in between. The nail acts as a central load carrier. The head fixation screws run through threaded holes in the proximal end of the nail thus being held in a stiff angle and without gliding. The entry points of these screws correspond to the anatomical main portions of the lesser and greater tubercle. They allow a three-dimensional screw grip to the subchondral bony layer of the head fragment. The purpose of this intramedullary construct is to keep the fracture stable at a grade which allows instant postoperative active exercise and which corresponds to the needs of mechanical tranquility in a predominantly endosteal healing area. In a prospective clinical study 45 patients could be followed up after 3, 6 and 12 months. We found an ongoing improvement of the postoperative results up to an average Constant Score of 85.7 pts after one year. The complication rate was 16 %. The main complication was the screw protrusion into the joint.