Biomechanical Analysis of Novel Occiput-C1-C2 Fixation Techniques

Introduction The etiology of occipitocervical instability is vast and includes trauma, rheumatoid arthritis, infection, tumor, congenital deformity, and degenerative processes. The development of instability in this region can result in intractable pain with or without neurological deficit and requires surgical treatment. Surgical management has evolved during the past decades, and currently, incorporation of an occipital plate system and C2 pedicle screws or C1-C2 transarticular screws for occipitocervical fixation is recommended. However, there are unique clinical situations in which this occipital plate system may not be possible (e.g. postoperation of posterior fossa decompression), may have already failed, or may require the addition of supplemental fixation. For these unique salvage or rescue situations, two novel techniques which utilize the occipital condyle as screw purchase in posterior approach have been recently introduced . One of the novel techniques is the C0C1 transarticular screw (TA) technique. Another is the direct occipital condyle screw (OcC) technique which is applied with a C1 lateral mass screw. Clinical application and anatomical feasibility of these two techniques have been reported . However, to our knowledge, there is no biomechanical study comparing these two techniques. The purpose of this study was to evaluate and compare the construct stability provided by C0-C1 transarticular screws or occipital condyle screws, especially as a salvage or rescue, reinforcement, or alternative technique.