Exploration of the Anatomical Methods for the Long Occipital Nerve.

Objective To further clarify the anatomical features of the long occipital nerve and summarize the rapid anatomical method for it,thus providing an operational basis for anatomists.Methods The bilateral sides of the head and neck specimens of 38 adult formalin-fixed cadavers were dissected,with a total of 76 specimens.The lateral cervical region,the sternocleidomastoid region,and the occipital region were dissected.The dissection focused on the long occipital nerve,the location and adjacent structural characteristics of which were carefully observed.Results The long occipital nerve was dissected out from 76 specimens.Through the posterior margin line(PML)anatomical method,the long occipital nerve was identified 1-3 cm above the accessory nerve,near the posterior border of the deep surface of the upper sternocleidomastoid in 70(92.1%)specimens.Through the inflection point(IP)anatomical method,the long occipital nerve was observed within the range of the circle with a radius of about 1.5 cm and centered on the midpoint of the line between the tip of the mastoid process and the tip of the external occipital protuberance in 6(7.9%)specimens.Conclusions The long occipital nerve can be quickly found by the PML method or IP method.Although the long occipital nerve can definitely be identified by the IP method,the anatomical operation is difficult.