Readers of the first volume of Progress in Orthopaedic Surgery may remember the introductory remarks of Drs. Wagner and Hungerford. It is the intention of the editors of this publication to familiarize English - speaking orthopaedists with articles published in the European literature which, because of language barriers, would otherwise be inaccessible to them. Most articles in this second volume also are translations of papers originally printed in Der Orthopiide. The purpose of this German medical journal is to disseminate the newest experiences of orthopaedic problems in a form that is of particular value to the practising orthopaedic surgeon. In 1973 eight articles were published on acetabular dysplasia. In his fore­ word to this issue Dr. Wagner stated some of the reasons why such an indepth study was deemed necessary. He was of the opinion that the shallowness and increase in acclivity of the acetabulum was of such central importance in the development and treatment of hip dysplasias that a volume dealing with this subject was fully justified. Another reason for this collection of papers was the advances made in correcting the results of a dysplastic acetabulum by surgical means and thereby improving hip joint function in later years, or at least pre­ venting its early deterioration.