Seyed Reza Mousavi - Department of Neurosurgery, Shiraz University of Medical Sciences, Shiraz, Iran AND Shiraz Neuroscience Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
Alireza Liaghat - Department of Neurosurgery, Shiraz University of Medical Sciences, Shiraz, Iran
Mohammadhadi Amir Shahpari Motlagh - Department of Neurosurgery, Shiraz University of Medical Sciences, Shiraz, Iran
Masoud Pishjoo - Department of Neurosurgery, Faculty of Medicine, Birjand University of Medical Sciences, Birjand, Iran
Amir Tarokh - Department of Neurosurgery, Shiraz University of Medical Sciences, Shiraz, Iran
Majidreza farrokhi - Department of Neurosurgery, Shiraz University of Medical Sciences, Shiraz, Iran AND Shiraz Neuroscience Research Center, Shiraz University of Medical Sciences, Shiraz, Iran

Background and Importance:  Developmental craniovertebral junction (CVJ) anomalies are often comprised of irreducible atlantoaxial dislocation (AAD) and basilar invagination (BI) associated with the fusion of the C۱ arch. BI is described as a congenital upward displacement of mostly the odontoid process into the foramen magnum, which AAD can accompany. The DCER (Distraction, Compression, Extension, and Reduction) consists of decompression of craniocervical junction, BI reduction followed by occipitocervical fusion in anatomic lordotic curvature –performing extension and compression. This technique has recently been applied in patients with BI and AAD, demonstrating satisfactory results. Case Presentation: Herein, we report two cases of BI with AAD who underwent surgery with the DCER technique for the first time in our center. Conclusion: BI has been managed with combined approach (anterior odontoid resection followed by posterior craniocervical fusion). Since last decade, single posterior approaches has been utilized to reduce and stabilize BI and AAD. DCER approach is the most recent and successful procedure.

Atlantoaxial dislocation, Basilar invagination, Compression, Distraction, Extension, Reduction