It is just six years since I had the honour of opening the discussion1 on this subject in London (July 4th, 1929) at the joint meeting of the British and American Ortho paedic Associations. At that meeting Smith-Petersen first demonstrated his new pin or nail and gave an account of his early work. I do not think that many who heard him were greatly impressed by either the theory or the practice he proposed. Certainly none of us realized that his proposition was going to dominate the whole situation in a few years. To-day I have as my first duty to pay an honest tribute to the genius of Smith-Petersen, and then to direct inquiry into the way in which his invention has modified our ideas of practice and prognosis. I wish that some kind of fracture register existed by which we could estimate at any time the number of different fractures that are presented for treatment. It is evident, however, that fractures of the femoral neck are both common and important ; this may be learned in the wards of any of the large municipal hospitals, where these cases are commonly " dumped," and where many of them remain for months or years. The fracture is of common occurrence ; it often requires a long period of treatment, and only too frequently results in permanent disability.