For many years, external fixation pin use was centered around the Kirschner-Ehmer (KE) external fixation device resulting in potentially confusing pin terminology that is poorly suited to the use of improved external fixation devices such as the IMEX® SK® external fixator. Modern, accurate terminology will clear up potential ordering errors and provide educators with a consistent vocabulary to train students, residents and practitioners. These changes will greatly simplify future pin discussion as well.
Using the medium KE clamp and a 3.2mm (1/8”) smooth pin as a common example, note that the term “medium” continues to be used for smooth, negative-profile and positive-profile pins, regardless of the fact that each creates a significantly different size and shape of pin tract in the patient’s bone. Since veterinarians were forced into using Kirschner terminology, a 3.2mm shaft positive-profile pin continued to be called a 3.2mm (1/8”) pin even though the thread diameter engaging the bone is actually 4.0mm.