The menifestation and imaging characteristics of the chronic atlantoaxial rotatory fixation or dislocation

English Keywords:Atlantoaxial  Rotatory fixation  Rotatory subluxation  Grisel′s syndrome

English Abstract:

  【Abstract】 Objectives: To investigate the clinical and radiographic features of patients with chronic atlantoaxial rotatory fixation or dislocation(AARF/AARD), and to explore the diagnosis and treatment experience. Methods: A series of 52 cases were diagnosed and treated in our hospital from September 2004 to February 2017, including 23 males and 29 females, with the mean age of 11.04 years and the mean course of 6 month. The clinical materials and images of the patients were all reviewed. 32 patients had a clear cause, of which 18 had a history of minor trauma to the neck. All patients had torticollis, diminished range of the rotatory motion and neck pain. Only 3 patients had minor neurological deficit. The anterior atlantoid space(ADI) was measured on imaging materials in all patients, the rotation and dislocation directions of atlantoaxial mass joints were observed. According to the classification on the basis of imaging findings, different treatment methods and outcomes were explored. Results: According to ADI and atlantoaxial rotatory displacement on X ray and CT, imaging types were divided into three: the first was atlantoaxial rotatory fixation (AARF) with normal ADI and two sides of the lateral mass displacing to anterior and posterior respectively (Type A); the second was atlantoaxial rotatory dislocation(AARD) with abnormal ADI(more than 5mm) and two sides of the lateral mass displacing in different directions and degrees respectively(Type B); the third was occipital-atlanto-axial rotatory dislocation(OAARD) with abnormal ADI(Type C). There were 7 cases of AARF, 44 cases of AARD and 1 case of OAARD. Four cases with AARF healed by traction and collar; 3 cases with AARF were treated with halovest fixation combined with surgical fusion, the mean course of AARF was 3 months. All cases with AARD were treated with surgical internal fixation and fusion, the mean course of AARD was 6 months. One case with OAARD failed to reduction and gave up the treatment. Conclusions: AARF/AARD mostly occurred in children. Patients of type A has shorter course than patients of type B, and may healed by conservative therapy. Meanwhile, patients of type B need surgical reduction and fusion, but no therapeutic experience of OAARD was obtained. Moreover, the imaging characteristics in the study were more comprehensive than previous classification.