Introduction of a Novel Integrated C1 Laminar Hook Combined with C1–C2 Transarticular Screws for Atlantoaxial Fixation

In practice, C1–C2 transarticular screw (TAS) combined with bilateral C1 laminar hooks could be used for atlantoaxial instability to avoid the risk of spinal cord injury which is usually caused by sublaminar wire inserting. But, a standard C1 laminar hook does not match the posterior arch of C1 well, and to connect it with the C1–C2 TAS is difficult. To solve this problem, we have designed an integrated C1 laminar hook based on measurement data acquired from human cadaveric cervical spine specimens and computed tomography images. This hook matches the atlantoaxial anatomy perfectly and facilitates connection to the C1–C2 TAS. Furthermore, the more medial contact point of this hook on C1 potentially improves leverage and the ability to clamp a block of bone graft tight. The biomechanical characteristics of this new C1 hook have been tested on human cadaveric specimens and compared with other internal fixation techniques commonly used [1].