Reasonable choice of occipitocervical angle and posterior occipitocervical angle in basilar invagination patients during occipitocervical fusion 
Yang Sheng, Tang Chao, Liao Yehui, Tang Qiang, Ma Fei, He Hongchun, Zhong Dejun
Chinese Journal of Tissue Engineering Research . 2020, (23): 3654 -3661 .  DOI: 10.3969/j.issn.2095-4344.2730