SummaryA deep knowledge of anatomic structures and pathways is an indispensable prerequisite for successful use of external fixation in the upper extremity. Bone substance and dimensions in the different areas should be taken into account as well as the position of the muscle bellies and gliding spaces between functional muscle groups and tendons, not least to mention the course of nerves and vessels. In some respects the surgeons view differs markedly from the anatomists view. Both are aware of anatomic structures but the surgeons who, for example, have to stabilize a long-bone fracture concentrates on safety corridors, trying to avoid damage to nerve and vessel routes as well as to other soft-tissue structures. The following description of anatomic features is meant to provide viewpoints and data for unilateral external fixation in the upper extremity without laying claim to completeness.