APLAR GRAND ROUND CASE A case with rheumatod arthritis and atraumatic odontoid fracture: disappearence of bonny landmarks Gulin FINDIKOGLU, 1 Fusun ARDIC, 1 Nuray AKKAYA, 1 Fusun SAHIN, 1 Nuran SABIR 2 and Bayram CIRAK 3 1 Deparments of Physical Medicine and Rehabilitation, 2 Radiology, and 3 Nerosurgery, University of Pamukkale, Denizli, Turkey Abstract We aim to draw attention to occult, atraumatic fractures of the odontoid process in patients with rheumatoid arthritis (RA) and to underline difficulties encountered during clinical and radiological diagnosis. A forty-seven years old man with RA for 4 years had occipital pain for 1 year without any history of trauma. Later, he developed weakness in the upper extremities, but he did not realize weakness in the lower extremities due to deformities. Contrast magnetic resonance imaging revealed a linear fracture of odontiod process and myelopathy. Cervical computed tomography scan revealed an old fracture border with separated and almost disappeared remnant of the tip of the odontoid without free particles in the cord. It was impossible to evaluate atlantoaxial and vertical subluxations with craniometric measurements due to destruction of the tip of odontoid. Following occipitocervical fusion and decompression and a rehabilitation program, his muscle strength improved; however, functional mye- lopathy stage did not change. Atraumatic fractures of the odontoid process may be more common than reported and may cause compression of the spinal cord or brain stem. Surgery is the treatment of choice but functional recovery is limited once neuronal damage has occurred. Erosion of the critical landmarks makes it difficult to diag- nose and follow up atlantoaxial subluxation and/or vertical subluxation, therefore clinicians should consider radiographical follow-ups during the course of the disease. Key words: atalantoaxial, axis, fracture, myelopathy, subluxation, vertebra, vertical. INTRODUCTION Structural changes of the most commonly involved region of the spine and cervical spine are well described in patients with long-standing rheumatoid arthritis (RA). 1 The common radiological features of cervical lesions in RA include atlantoaxial subluxation (AAS), vertical subluxation (VS), subaxial subluxation and a combination of these. 2 The majority of RA cases with radiological abnormalities remain asymptomatic for years; however, those with progressive upper cervical spine involvement hold the risk of severe neurological complications. Once neurological deficits occur, pro- gression seems inevitable. These findings may detoriate to brain stem compression. 3 Occult fractures to the odontoid process of the axis are described rarely in the literature. 4–10 Similarity of clinical presentation to that of AAS and very slow rate of progression cause additional difficulties for diagnosis. 1 We report a case of RA presenting with an atraumatic odontiod fracture accompanied by lysis of dens and complicated by AAS that resulted in myelopa- thy. We also want to draw attention of clinicans to the pitfalls of radiological diagnosis when commonly used osseous landmarks are eroded, invalidating most of the craniometric criteria used for AAS and VS. In addition to the clinical follow-up, periodical radiographic evaluation could prevent the development of such complications. Correspondence: Gulin Findikoglu, MD, PhD, Assistant Profes- sor, Department of Physical Medicine and Rehabilitation, University of Pamukkale, Denizli, Turkey. Email: gulin_dr@yahoo.com This case was appeared as a poster presentation at the 23rd National Congress of Physical Medicine and Rehabilitation, Turkey. © 2014 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd International Journal of Rheumatic Diseases 2014