Anterior decompression through transoral axis slide and rotation osteotomy for salvage of failed posterior occipitocervical fusion: a novel technique note

Atlantoaxial dislocation could be caused by odontoid fractures or Os odontoideum. The previous surgical techniques in treatment of atlantoaxial dislocation were based on arch remove decompression or anterior atlantoaxial release and atlantoaxial (occipital-cervical) screw fixation-based reduction and fusion. However, for some clinical situations, all of above techniques cannot be applied. In this study, a patient with atlantoaxial dislocation caused by Os odontoideum treated by posterior occipitocervical fusion 20 years ago and failed. We design a novel anterior decompression through transoral axis slide and rotation osteotomy for salvage of this failed posterior occipitocervical fusion case. The C2 body and odontoid process was ventrally slide and rotation at good position after operation as well as the position of plate and screws, the spinal canal was increased significantly after operation too. We suggest this anterior decompression through transoral "C2 slide and rotation" technique is good choice for salvage of failed posterior occipitocervical fusion and some irreducible atlantoaxial dislocation because of the anterior bony fusion, it could direct decompress the spinal cord anteriorly, avoid the odontoid resection, and is feasible and safe technique.