The editorial group has selected these papers for publication in Progress in Orthopaedic Surgery from contributions to the "Reisensburg Workshop of Clinical Trauma Surgery" dealing with the lesions of knee ligaments and cartilage in 1975. They represent a survey of today's knowledge of pathophy­ siology, diagnostic means, and therapy of these lesions in the German-speaking countries. There are two "Reisensburg Workshops" annually, covering current topics of traumatology sponsored by the Ulm trauma group. Primary attention is focused not upon review lectures but rather upon the extensive discussions thus resulting in recommendations to the practising trauma surgeon in order to facilitate his clinical work. Ulm, November 1977 C. Burri, A. Ruter Introduction This volume of Progress in Orthopaedic Surgery presents a selection of papers dealing with injuries to the ligament support and articular surfaces of the knee. The menisci are not discussed as separate entities, but rather in their correct perspective as part of the knee jointsupport mechanism. As the editor for this volume, I have tried to select the most representative articles which cover this subject. These are publications from our European colleagues and reflect their opinion and experience. I have tried not to change their content or meaning in any way. This volume has been divided into six basic segments. Each deserves comment.

Biomechanics and Pathophysiology.- The Biomechanics and Pathophysiology of the Knee Ligaments.- The Pathophysiology of Damage to Articular Cartilage.- The Reaction of Articular Cartilage to Pressure, Immobilization and Distraction.- The Acute Knee Ligament Injury.- The Treatment of Acute Knee Ligament Injuries.- The Rehabilitation of Knee Ligament Injuries.- Chronic Knee Ligament Instability.- Rotational Stability of the Knee.- The Treatment of Unstable Knees.- Pedicled Grafts in the Treatment of Unstable Knees.- Free Autologous Skin Grafts in the Treatment of the Unstable Knee.- The Acute Cartilage Injury.- Arthroscopy in Articular Cartilage Injury.- Posttraumatic Cartilage Impression of the Femoral Condyle.- The Isolated Shear Injury to Articular Cartilage.- Internal Fixation of Osteochondral Fragments.- The Old Cartilage Injury.- An Experimental Basis for Cartilage Transplantation.- Osteochondrosis Dissecans.- Retropatellar Cartilage Degeneration.- Retropatellar Cartilage Degeneration: Diagnosis and Outline of Treatment.- Patellar Shaving (Indications, Technique, Results).- Retinacular Release: Indications, Technique, Results.- Anterior Displacement of the Tibial Tuberosity.- List of Contributors.