Letter to the Editor concerning "Is the 4 mm height of the vertebral artery groove really a limitation of C1 pedicle screw insertion?" (by Da-Geng Huang, Si-Min He, Jun-Wei Pan, et al. Eur Spine J, 2014, 23(5):1109-1114).

Letter to the Editor concerning "Is the 4 mm height of the vertebral artery groove really a limitation of C1 pedicle screw insertion?" (by Da-Geng Huang, Si-Min He, Jun-Wei Pan, et al. Eur Spine J, 2014, 23(5):1109-1114).