Posterior atlantoaxial fusion. A new internal fixation device.
Biomechanical and clinical testing of an atlantoaxial posterior fixation device. The authors tested an internal fixation device to maintain the atlas and axis in an anatomic relationship while fusion occurs. The device should also facilitate intraoperative reduction of any residual anterior atlantoaxial subluxation. The device should allow the use of cancellous rather than cortical bone graft. Previous techniques of atlantoaxial fusion were not universally successful, and the quality of reduction was assessed infrequently. Biomechanical testing of the fixator and clinical use in two "problem" patients requiring atlantoaxial fusion. Biomechanical testing indicated the device should be successful. Clinical testing was successful. The new fixator facilitates posterior atlantoaxial fusion in an anatomical position.