Current Concepts in Posterior C1-C2 Fixation

Historically, fixation into C1 has been limited by the inability to attach a stable, longitudinal construct to the adjacent motion segments. Over the past several years, the introduction of universal polyaxial screw/rod instrumentation for the posterior cervical spine has enabled the surgeon to individually anchor into C1 and C2, providing stability comparable to transarticular screws, versatility of incorporating the occiput and the subaxial cervical spine easily into the construct, with safer and less difficult screw insertion. There has been considerable confusion in the literature regarding screws placed into the C2 vertebra from a posterior approach, with the distinction between C2 pedicle screws and C2 pars interarticularis screws hinging on the anatomic definitions of the true pedicle and pars interarticularis. Additionally, the recent advent of the C2 intralaminar screw has been introduced as a safe, alternative option for purchase into the C2 vertebra. We present a detailed discussion of the current trends in posterior atlantoaxial fixation.