Abstract
Introduction : Various surgical fixation techniques exist to obtain atlantoaxial stability. This study reports a retrospective review of 76 surgically treated cases through a standard posterior midline approach. Materials and Methods : There were 30 men and 46 women, the age range at the time of operation was 14 to 80 years. Forty-six had Rheumatoid arthritis (RA), 12 trauma, 8 Os odontoideum, 2 odontoid fracture, 1 von Recklinghausen's disease and 7 unknown. Forty-eight were treated with posterior wiring (modified McGraw; 41, Brooks; 7), 28 were treated with transarticular screw fixation (Magerl's method). All patients were followed with serial radiographs (lateral flexion-extension) until solid fusion or failure was documented. Results : There was no neurological deficit and no iatrogenic vascular injury. Thirty-nine of 48 (81.3%) with posterior wiring had osseous union, three had fibrous union but were stable, and six had non-union. Wire breakage was observed in two cases seemingly due to technical failure. Reoperations were performed in two patients, who were mutilans type and could not be applied a Halo vest because of severe RA. Magerl's method had gained osseous union without using a Halo vest in all patients. There was no difference in the fusion rate between cases with flexible cables or nylon threads. Loosening occurred in the flexible cable and the shape of the cable became to oval or ring-like. Postoperatively in 8 of 36 patients (22.2%) who had atlantoaxial arthrodesis, subaxial subluxation developed. Conclusion : The results obtained using Magerl's method were satisfactory. This method was useful for atlantoaxial subluxation and thought it rigid stability and solid fusion were obtained. Transarticular screw fixation and posterior bone graft supplemented by nylon thread to hold the graft achieves arthrodesis reliably.
