Launching the DCER (Distraction, Compression, Extension, and Reduction) Technique in Basilar Invagination and Atlantoaxial Dislocation: A Preliminary Report of Two Cases in 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 C1 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.