Object: The authors conducted a study to describe the detailed anatomy of the apical ligament and to acknowledge or refute its historical description as a functionally significant contributor to craniocervical stability.
Methods: In 20 adult human cadavers measurements of the apical ligament were obtained, and its detailed anatomy was observed. Ranges of motion were also assessed to discern the function of the apical ligament.
Conclusions: Results of the study support the concept that the apical ligament is best described as a vestigial structure that offers no significant added stability to the craniocervical junction. In fact, this ligament was absent in 20% of the specimens examined. These data will aid physicians who frequently view images or manage clinical problems of the craniocervical junction because they may focus on other ligaments of this area and not the apical ligament.