Posterior-only approach for treatment of irreducible traumatic Atlanto-axial dislocation, secondary to type-II odontoid fracture; report of a missed case, its management and review of literature.

INTRODUCTION AND IMPORTANCE: Odontoid fracture (OF) is among the most common and challenging cervical spine fractures in regards to the treatment and surgical approach. Atlanto-axial dislocation (AAD) is considered a significant complication after failed non-surgical treatment of OF. Traditionally, it requires anterior odontoidectomy followed by posterior C1-C2 reduction and fusion. In latest studies, Atlanto-axial joint (AAJ) remodeling in a posterior-only approach has got attention. CASE PRESENTATION: We herein present a 30-year-old man with missed type-II OF, presenting with irreducible anterior AAD and progressive neurological deficit. Old non-united OF with dorsal callous formation, compressing spinal cord, was detected. The patient underwent correction of the deformity and reduction of the fracture utilizing the posterior-only approach. AAJ remodeling, callous release and C1-C2 fusion was performed in standard prone position, under fluoroscopic guide and intraoperative electrophysiological monitoring. The patient had uneventful surgery and postoperative course and was neurologically intact with appropriate alignment in 6-month follow-up. CLINICAL DISCUSSION: The irreducible AAD following type-II OF could be successfully treated with posterior-only approach (C1-C2 fusion). CONCLUSION: Type-II OF is considered unstable requiring surgical management. Close follow-up and appropriate patient education is mandatory in non-surgical treatment. Irreducible AAD has been managed with anterior odontoid resection and posterior fusion. Several complications of anterior surgery, makes posterior-only approach a noticeable choice.