POSTERIOR ATLANTOAXIAL FUSION - A NEW INTERNAL-FIXATION DEVICE

Study Design. Biomechanical and clinical testing of an atlantoaxial po sterior fixation device. Objectives. The authors tested an internal fi xation device to maintain the atlas and axis in an anatomic relationsh ip while fusion occurs. The device should also facilitate intraoperati ve reduction of any residual anterior atlantoaxial subluxation. The de vice should allow the use of cancellous rather than cortical bone graf t. Summary of Background Data. Previous techniques of atlantoaxial fus ion were not universally successful, and the quality of reduction was assessed infrequently. Methods. Biomechanical testing of the fixator a nd clinical use in two ''problem'' patients requiring atlantoaxial fus ion. Results. Biomechanical testing indicated the device should be suc cessful. Clinical testing was successful. Conclusion. The new fixator facilitates posterior atlantoaxial fusion in an anatomical position.