Atlanto-axial lateral mass osteoarthritis. Three case reports and review of the literature

This report describes three cases of symptomatic unilateral C1-C2 mass oste oarthritis, The patients were all female aged 67, 62 and 59 years. One pati ent had a history of rheumatoid arthritis. Unilateral occipital pain was th e main symptom. Neuroradiological work-up included open mouth anteroposterior radiograph, f lexion/extension lateral radiograph of the cervical spine, CT scan with cor onal and sagittal reconstruction and MRI. Findings allowed differential dia gnosis with tumoral or infections disease of tipper cervical spine and rule d out C1-C2 instability. CT scan and MRI permitted precise operative planni ng by determining the course of vertebral artery in the C1 and C2 vertebrae . Two patients were treated by CT scan guided steroid injection. The third pa tient was treated by CI-CZ arthodesis after failure of conservative treatme nt.