Management of C1-C2 Myelopathy Due to Periodontoid Pseudotumor With a Successful Posterior Stabilization and Decompression: A Case Report.

Periodontoid pseudotumors are caused by chronic instability in the atlantoaxial joint, possibly leading to cervical myelopathy. The classic treatment is transoral resection of the pannus, followed by posterior stabilization. More recently, some cases showed regression of the inflammatory mass following stabilization alone. A 71-year-old female patient presented with cervical pain and decreasing muscular strength and dexterity in the upper limbs. Objectively, muscular strength grade IV, Hoffman sign positive bilaterally, unbalanced and wide base gait and changes in voiding pattern were noted. The CT scan showed a slight C1-C2 subluxation and C3-C6 diffuse idiopathic skeletal hyperostosis. MRI showed a large retro-odontoid inflammatory mass with stenosis at C1-C2 and multilevel discopathy with degenerative changes causing stenosis at the C5-C6 level, leading to severe C1-C2 and C5-C6 myelopathy. The patient was subjected to a C1-C6 laminectomy and occipito-C6 posterior fixation. After surgery, muscular strength, gait difficulties and pain slowly improved, with acquired autonomy. Control MRI, one year after surgery, showed complete resolution of the periodontoid pannus. In the present case, we were able to achieve a satisfactory result, with clinical improvement and radiological resolution of the inflammatory mass, with posterior stabilization of the cervical spine, without transoral approach.