Study design: In this study, 10 patients with chronic irreducible atlantoaxial dislocation were treated by transoral anterior decompression and fusion.
Objectives: To examine the benefits of the transoral approach, the patients treated with this procedure were compared with the historical control subjects after 2 years of follow-up.
Summary and background data: Chronic irreducible atlantoaxial dislocation with cord compression is difficult to treat because the cord is compressed posteriorly by the posterior arch of the atlas as well as anteriorly by the posterior-superior portion of the axial body and nonunited dens. Its irreducibility, as a result of the bony scarring between the dens and the anterior body of the axis, and the locking of the lateral joints of C1-C2, makes reduction more complex. Posterior surgical approaches have been associated with high morbidity and mortality.
Methods: Ten patients were diagnosed and followed up by clinical symptoms, radiography, pantopaque myelography, and computed tomography. They were treated surgically by transoral decompression and fusion. During the surgery the nonunited dens as well as callus, granulation, and scar tissue were removed; the cartilage of the articular surfaces of the atlantoaxial joint was excised. Postoperative treatment included skull-cervical biaxial traction, tracheostomy care, nasal feeding, and Minerva cast.
Results: The 2- to 6-year follow-up showed that four out of 10 patients recovered completely and returned to work, three recovered to a great degree and ambulated, two partially recovered, and one recovered poorly.
Conclusion: Transoral decompression and fusion offered satisfactory results in a series of patients with chronic irreducible atlantoaxial dislocation. None of the patients showed serious complications of stability, even though only one had a secondary posterior fusion. Therefore, anterior decompression associated with subtotal obliteration of the atlantoaxial joints without bone grafts is a feasible therapy for irreducible atlantoaxial dislocation using a multifunctional bed and biaxial traction.