The author was the 1987 Sir Robert Jones Lecturer of the Hospital for Joint Diseases Orthopaedic Institute. This article is based on the speech he delivered in that capacity on October 30, 1987, at the Annual Scientific Program of the Alumni Association, supplemented by material he presented at a three-day International Conference on the Ilizarov Techniques for the Management of Difficult Skeletal Problems which was sponsored by HJDOI November 1-3, 1987.