Intraoperative reduction and internal fixation for atlanto-axial dislocation

Abstract

Atlanto-axial complex is the most important functional unit of the cervical spine. Atlanto-axial instability or dislocation, one of the most serious pathologies in spinal surgery, is often managed by posterior atlantoaxial fixation and fusion. Several posterior fixation techniques have been used to stabilize the atlanto-axial complex, including wire/cable-bone fixation, Halifax clamps, transarticular screw fixation, screw-plate fixation and screw-rod fixation. For atlanto-axial dislocation that cannot be reduced with skull traction before operation, intraoperative reduction is often needed. Current intraoperative reduction techniques can be classified into tran-soropharyngeal surgical release followed by posterior reduction and fixation, transoropharyngeal reduction and fixation, and posterior reduction and fixation using screw-rod system according to approaches. Furthermore, posterior reduction can be performed using elevating-pull, leverages, and cantilever techniques. This study re-views the intraoperative reduction and fixation techniques mentioned above. Key words: Atlas; Axis; Dislocation; Reduction; Internal fixation