Journal of orthopaedics and traumatology vol:1 pages:57-61
Six years after a successful atlanto-axial fusion for a case of os odontoideum, a post-mortem radiological, anatomical and histological examination was performed. This showed the os odontoideum being separated from the base of the dens by a ligamentous structure. No evidence for the existence of disc tissue or a pseudoarthrosis was found. The literature was reviewed with focus on embryological data and anatomical and histological findings. We conclude that this case of os odontoideum was caused by a defective development of the cartilage anlage of the axis during the sixth to eigth fetal week approximately.