The Grisel's syndrome: A non-traumatic subluxation of the atlantoaxial joint

Introduction: Grisel's syndrome consists in rotational subluxation of C1-C2 following ENT infection or surgery. There is no consensus on management. We present 2 cases requiring surgical treatment in our center. Case reports: Two 10-year-old patients presented torticollis with cervical pain resistant to medical treatment, with onset a few months after tonsillectomy. In both cases, radiological assessment, comprising CT scan and MRI, showed Fielding-Hawkins type-3 C1-C2 rotational subluxation, without ligament lesion. After failure of conservative treatment, posterior reaming, realignment, C1-C2 arthrodesis using lateral masses and pars interarticularis screws and bone graft achieved good fusion and immediate spinal stability in all planes of the atlantoaxial complex. Discussion: Grisel's syndrome consists in non-traumatic subluxation of the atlantoaxial joint with intact atlantoaxial ligaments. Initial pharyngeal inflammation spreads to the prevertebral fascia via direct connections between the periodontoidal venous plexus and pharyngovertebral veins, inducing fasciitis that leads to abnormal relaxation of the atlantoaxial ligaments and reactional muscle contraction with ankylosis. This phenomenon, appearing gradually and insidiously over a period of a few weeks, creates a frozen joint with ankylosis. Medical treatment with NSAIDs, muscle relaxants, and immobilization is usually sufficient; cervical traction may be needed. Surgical treatment by C1-C2 arthrodesis is indicated in case of failure of medical management or onset of neurologic signs. Conclusion: Close collaboration between pediatricians, ENT surgeons and neurosurgeons is essential for early diagnosis and management, which is the main prognostic factor for successful medical treatment, avoiding surgery. Keywords: Atlantoaxial subluxation; Grisel's syndrome; Juvenile torticollis