Discussion
The atlantoaxial joint is compounded of three synovial joints: the median joint (atlanto-odontoid joint) and two lateral joints (facet joints).
Atlantoaxial septic arthritis is scarce. To our knowledge, only 2 cases of atlanto-odontoid arthritis have been reported in the literature [1,2].
Clinical presentation can include neck pain, fever, paravertebral muscle contracture, and restricted neck movement. Inflammatory markers are often increased. Nevertheless, they were within the normal limit in a case of septic arthritis of the facet joint [3].
MRI allows an early diagnosis of synovitis of atlanto-odontoid joint. In this stage, different diagnoses may be discussed such as cervical spine crystal deposition, rheumatic inflammatory diseases especially rheumatoid arthritis, and infectious atlanto-odontoid arthritis. At a late stage, MRI can show epidural collection, abscess, and spinal compression. In our case, the presence of epidural collection led to the diagnosis of a septic atlanto-odontoid joint.
The identification of the bacterial agent is sometimes difficult. Staphylococcus aureus is the most causative agent in septic cervical arthritis [1].
Although the presence of epidural collection in our case, the conservative treatment led to clinical and imaging improvement of the septic atlanto-odontoid joint. Septic arthritis C1-C2 can be responsible for serious complications such as neurological compression and cerebral thrombosis. [4] In our case, internal venous thrombosis was due to neck abscess. Signs and symptoms of internal venous thrombosis can associate swelling and sensitivity along the front edge of the sternocleidomastoid muscle [5].