Türk Nöroşirürji Dergisi 2015 , Vol 25 , Num 2
Os Odontoideum
İstanbul Arel Üniversitesi, İstanbul, Türkiye Os odontoideum is an independent ossicle of variable size with smooth circumferential cortical margins separated from the foreshortened odontoid peg. The etiology of os odontoideum remains controversial, but there is both emerging consensus on the traumatic etiology and a congenital source. Patients with this condition can be asymptomatic or present with a wide range of neurological dysfunctions. Although the diagnosis of os odontoideum can be made with plain x-rays, further imaging modalities including magnetic resonance imaging and computed tomography with angiography have improved the preoperative surgical planning. There is a role for conservative treatment of an asymptomatic incidentally found, radiologically stable, and non-compressive os odontoideum. However, surgical treatment has a definitive role in symptomatic cases. The main method of surgical treatment today is microscopic posterior decompression after reduction and fusion via independent C1 and C2 fixation. Irreducible, persistent anterior compression from os odontoideum can be approached by a transoral route with good results in experienced hands. Complications are extremely low and at an acceptable level. We reviewed the literature relevant to os odontoideum in this chapter. Anahtar Kelimeler : Atlanto-axial instability, C1-2 fusion, Os odontoideum, Posterior arthrodesis