This book was conceived with the object of presenting to doctors and medical students with a potential interest in the disciplines of orthopaedic surgery, diagnostic radiology and orthopaedic pathology, a volume which would contain basic and essential information concerning those disorders of the skeleton in which a common interest exists. Diagnosis in such conditions is dependent on close collaboration between specialists in these subjects. As medical knowledge has advanced, so the necessity for detailed specialisation has increased. As a result co-operation in a combined approach has become of great importance. The method of presentation, in the form of Exercises, is designed to permit readers to test their own diagnostic ability. The book consists of ninety-four problems of diagnosis which might be encountered in any orthopaedic unit. The case material has been chosen to emphasise those conditions in which appreciation and integration of the clinical, radiological and pathological features are required in order to establish the diagnosis.