Atlantoaxial Fixation—Anterior or Posterior Approach: Critical Review

Atlantoaxial facet joints have been proposed as the center of mobility and also center for instability of the atlantoaxial region. Because of the high mobility of the atlantoaxial (C1-C2) motion segment, fusion rates at this level have been substantially lower than those at the subaxial spine. The success of craniovertebral junction surgery depends on adequate reduction, decompression of craniovertebral (CV) junction followed by immediate fixation of atlantoaxial joint followed by bone grafting with compression for solid bony fusion. Current options for atlantoaxial fixation include anterior or posterior approaches. The biomechanical stability and fusion rates of posterior fixation surgery had been proved beyond doubt. The main disadvantages of posterior surgery involve disruption of posterior ligamentous complex which are essential for stability. C2 root denervation also aggravates the paraspinal muscle atrophy leading to instability So now advances in spinal surgery made neurosurgeons to think of an anterior technique which can establish fusion and fixation at the same time avoiding the above mentioned complications. The advantages are that there are no anatomical constraints like posterior approach in reaching C1-C2 joint. The risk of neuralgia, bleeding from venous plexus is avoided along with practically no damage to vertebral artery. Newer techniques of anterior transarticular screw and bilateral atlantoaxial fixation and fusion through unilateral right sided retropharyngeal approach had been described in literature. Anterior approach still needs further randomized controlled trials for level 1 evidence, Further research on along with biomechanical feasibility using anatomical ex vivo and in vivo constructs need to be done to further validate the appropriateness and safety of anterior approach for C1-C2 fixation and fusion.