Unusual Upper Cervical Spine Disorder and Non-traumatic Atlantoaxial Rotatory Fixation in an Adult: A Case Report

This study reports on an extremely rare case of non-traumatic atlantoaxial rotatory fixation (AARF) in an adult. Although there are numerous reports on traumatic AARF in adults, those on non-traumatic AARFs are limited. We present the case of a 25-year-old woman who developed neck pain with a limited range of motion (ROM) that began upon waking without any particular inducement. Physical examination showed a characteristic torticollis neck posture called the cock robin position. The patient exhibited severely limited neck mobility with no neurological deficits. Computed tomography (CT) revealed that the atlas was rotated to the right in relation to the axis, resulting in a diagnosis of AARF Fielding type 1. Conservative treatment was adopted by immobilizing the cervical spine using a soft neck collar. Four weeks post-treatment, all symptoms improved with no adverse complications. We present an extremely rare case of non-traumatic AARF in an adult patient. As surgical treatment may be necessary if the diagnosis is delayed, appropriate diagnosis and treatment should be made in the early stages.