Posterior Rotating Rod Reduction Strategy for Irreducible Atlantoaxial Subluxations With Congenital Odontoid Aplasia

Study Design. Applying rotating rod techniques to reduce irreducible atlantoaxial dislocation. Objective. To spare the occipital-C1 motion by the strategy in reduction of before surgery irreducible atlantoaxial dislocation with obvious neurologic symptoms and congenital odontoid aplasia. Summary of Background Data. The treatment of atlantoaxial dislocation (AAD) is a challenging problem for most surgeons. Posterior surgical stabilization of C1 and C2 include C1-C2 transarticular screws, or C1 lateral with C2 pars screws. These constructs, however, are based on preoperative reductions. When preoperative skull reduction fails and myelopathic symptoms coexist, long-segment cervico-occipital fusion and decompression are usually the only practical choice. Methods. The authors explored a different surgical technique to spare the axial occipital joints by rotating rods in polyaxial C1, C3 lateral mass, and C2 pars screws, functioning as a lever analogue. Three before surgery irreducible AAD cases with obvious neurologic symptoms and congenital odontoid aplasia were successfully reduced and fused with this procedure. The authors used intraoperative somatosensory-evoked potential monitoring and intraoperative fluoroscopy. Preoperative skull traction was employed to distract and help extend the atlantoaxial complexes. Results. Three C1-C2 dislocations were reduced completely without any deterioration of neurologic signs. Cervical myelopathic symptoms recovered soon after the operation. No atlantoaxial subluxation recurred. They returned to their normal work and/or activities. Conclusion. The rotating rod strategy is a viable option to reduce and fuse C1-C3 for AAD with odontoid aplasia. It spares the occipital-C1 motion.