Primary clinical trial of limited fixation for unstable Atlas fracture.

To clinically validate feasibility, safety and value of the C1 later-mass screw C2 pedicle screw and crosslink compression fixation technique.

[corrected] In previous clinical studies, several techniques have been introduced to fix Atlas fracture. But all these treatments have intrinsic disadvantages. Now seeking a means of limited internal fixation has become a worthwhile subject of clinical study.

From January 2001 to December 2004, 17 cases of atlas fracture were diagnosed consecutively, 11 cases were operated on with C1 lateral mass and C2 pedicle screws and crosslink fixation, of whom 6 patents had axial instability and rupture of transverse ligament, 1 patient had C2 laminal fracture, and the remaining 4 patients had axial instability. With the assistant of regional anatomy study and fluoroscopy C1 lateral mass screws and C2 pedicle screws were implanted in place, between which connecting rods were applied bilaterally. A crosslink compression was applied between the 2 rods to achieve realignment of C1 lateral mass fracture and C0-C1-C2 into the anatomic position. C1-C2 fusion with posterior bone grafting was performed in patients with axial instability or transverse ligament discontinuity.

Operative time ranged from 90 to 176 minutes with a mean of 124 minutes. Intraoperative blood loss ranged from 270 to 1200 mL with a mean of 432 mL. There were no neurologic deficits, vertebral artery related complications or other complications in all patients. No deterioration of the neurologic deficits was noticed 5 days after operation when the patients were brace fixed and began to ambulate. No cerebral hemodynamic deficit was observed in this patient. Radiograph examination showed bone fusion and stability in all patients 3 months after operation. Healing of C2 fracture was confirmed by computed tomography scan.

Osteosynthesis of the atlas by C1 lateral mass screws C2 pedicle screws and crosslink compression fixation is an ideal option for C1 burst fracture with or without rupture of the transverse ligament. The procedure allows for partially physiologic reconstruction of the C0-C1-C2 joint and shortens external fixation.