The principal characteristics of the technique for osteosynthesis of the neck of the femur which has been described are as follows:

1. A stud-bolt screw with a very sharp and high helicoid thread has been devised. The thread takes hold only in the head of the femur. The screw is cannulated, so that it may be guided by a Kirschner wire previously inserted.

2. An electric drill, also cannulated, is used. It has the great advantage of perforating the head and the neck very smoothly. In this manner, the separation or turning of the head while the channel is being made is avoided.

3. No hammering is required, and the operation produces minimal trauma.

4. As the head of the femur is so firmly held against the neck that it amounts to impaction, no rotation or flexion can take place at the site of fracture. The weak point of most of the methods previously in use has been the lack of this firm anchorage of the head of the femur.

5. The technique dispenses with the application of a cast. Patients are allowed to sit up in bed on the day of the operation. Eight of the author's patients were permitted to walk without a cast from nine to twenty days after operation. This shows the solidity of the synthesis. Roentgenograms taken thereafter showed no evidence of movement of the fragments. Active motion should be instituted from the beginning.

6. The screw has always been well tolerated, and up to the present the author never has had to operate for extraction of the screw.