Atlantoaxial arthrodesis using Halifax interlaminar clamps reinforced by halo vest immobilization: a long-term follow-up experience.

Thirty-two patients who underwent atlantoaxial arthrodesis using Halifax interlaminar clamps and halo vests between January 1989 and December 1992 were reviewed. The atlantoaxial instabilities were related to trauma in 16 patients, including 14 patients with unstable odontoid fractures, 1 patient with a complex C2 fracture, and 1 patient with a disrupted transverse ligament. Of the other 16 patients, whose atlantoaxial instabilities were nontraumatic in origin, 9 had instabilities that were secondary to rheumatoid arthritis, 1 had instability that was secondary to tuberculous infection, and 6 had instabilities that were caused by os odontoideum. The patients were followed postoperatively with lateral cervical radiographs for an average of 37 months (range, 16-59 mo). Solid atlantoaxial arthrodeses were achieved in all (100%) of these 32 patients after 32 to 111 days (average, 84.5 d) of halo immobilization, indicating atlantoaxial arthrodeses can be reasonably anticipated when Halifax interlaminar clamps with autogenous iliac bone grafting are reinforced by halo vest immobilization for 3 months.