The fourth volume of Progress in Orthopaedic Surgery is somewhat different from pre­ vious publications of the series. The editors have again tried to present two topics but the publications presented from the European literature are of very recent origin. In the age of total joint replacement it was felt to be imperative to counteract the pre­ sent tendency to treat every joint which does not seem to be healthy with an artificial re­ placement. Orthopaedic surgery seems to be influenced by trends. In 1963, E. A. Nichol discussing intracapsular hip fractures, quoted from Alice In Wonderland in an editorial written for volume 45B of the Journal of Bone and Joint Surgery "The Queen had only one way of settling all difficulties, great or small, "Off with his head"!". Today one could paraphrase his implied critizism by saying "Out with the joint". No one doubts that joint replacements have been of great value in treating degenerative joint changes, but it is already apparent that replacement operations are not the ultimate answer for treating every joint deformity. This volume represents the European experience of different types of surgery in treat­ ing arthrosis of the joints of the lower limb. A reader of the Anglo-American literature will find suggestions in it which reaffirm his uneasiness in considering only one solution for problems concerning lower limb joints. I feel strongly that there are other ways which allow a patient to function well with less extensive operations.