A primer of fixator devices and configurations.

This paper gives a general introduction to the terminology, concepts, and classifications of external fixators. A clear distinction is made between characteristics typical of the three types of external fixators, simple, clamp, and ring, and those typical of the four standard frames that can be built with each of the devices. These four frames, the one-plane unilateral, two-plane unilateral, one-plane bilateral, and two-plane bilateral configurations, differ in the ease of wound access they allow and their mechanical balance, particularly toward bending moments. Hybrids of different devices and frames may prove beneficial for stabilizing complex injuries.