Unstable atlas fracture treatment by anterior plate C1-ring osteosynthesis using a transoral approach

Study design

A retrospective study was conducted to evaluate anterior plate fixation of unstable atlas fractures using a transoral approach.

Objective

To further investigate the safety and efficacy of this surgical technique, as there is currently a paucity of available data.

Summary of background data

While most atlas fractures can be managed by external immobilization with favorable results, surgery is usually preferable in highly unstable cases. Surgical stabilization is most commonly achieved using a posterior approach with fixation of C1–C2 or C0–C2, but these techniques usually result in loss of joint function and cannot fully stabilize anterior arch fractures of the atlas. Although a transoral approach circumvents these issues, only nine cases were described in the literature to our knowledge.

Methods

Twenty patients with unstable atlas fractures were treated with this technique during a 6-year period. Screw and plate placement, bone fusion, and integrity of spinal cord and vertebral arteries were assessed via intraoperative and follow-up imaging. Neurologic function, range of motion, strength, pain levels, and signs of infection were assessed clinically upon follow-up.

Results

There were no incidents of screw loosening or breakage, plate displacement, spinal cord injury, or vertebral artery injury. A total of 20 plates were placed and all 40 screws were inserted into the atlas lateral masses. CT scans demonstrated that two screws were placed too close to the vertebral artery canal, but without clinical consequences. Imaging demonstrated that bone fusion was achieved in all cases by 6 months postoperatively, without intervertebral instability. No plate-related complications were observed in any patients during the follow-up period.

Conclusions

C1 anterior plate fixation using a transoral approach appears to be a safe, reliable, and function-preserving surgical method for the management of unstable atlas fractures. For this type of fracture, a transoral approach with anterior fixation should be considered as an alternative to posterior approaches or conservative treatments.