The incidence and anatomical features of the McKenzie branch: a cadaver study

The aim of this study was to demonstrate the morphological characteristics of the connections between the spinal accessory nerve and the anterior root of the first cervical nerve (C1) which is also called the McKenzie branch. The cranial cervical regions of 49 specimens from 27 human cadavers were used for this study under an operating microscope. The topographical relationship of the accessory nerve to the anterior roots of C1 were studied. One cadaver had a connection branch (McKenzie branch) on both sides. The knowledge of the anatomy of these connections may help the clinician in determining treatments and surgical approaches in this anatomical area.