Abstract
Introduction
While the majority of C1 fractures are treated nonoperatively with external immobilization, there is a subset of C1 fractures known to be unstable. In addition, current literature-based outcomes of nonoperatively managed C1 ring fractures have not been completely favorable, and therefore, leave room for treatment alternatives. Our goal was to evaluate a series of unstable C1 fractures treated with primary internal fixation without fusion (ORIF) to assess clinical and radiographical outcomes.
Patients and Methods
A retrospective review of all patients with C1 fractures between September 2002 and November 2012 identified 10 consecutive patients from a level I trauma center (Harborview Medical Center, Seattle, Washington United States) who were treated with primary internal fixation without fusion. EMR charts and radiographs were reviewed. The surgical technique consisted of a posterior cervical approach to C1 arch and open reduction utilizing bilateral C1 lateral mass screws connected transversely with a rod. Primary outcome measures included radiographical reduction, maintenance of reduction, ROM, and complications. Pre- and postoperative CT scans were utilized to assess reduction.
Results
A total of 10 patients with mean age of 53 years were identified to have undergone primary C1 ORIF. The cohort consisted of eight males and two females of which eight unilateral sagittal split–type fractures and two Jefferson burst–type fractures were identified. Mean follow-up was 13 months. Of the 10 patients, there were 2 associated complications, 1 errant screw requiring return to the operating theater for reposition, and 1 osteonecrosis of the lateral mass though the fracture healed. Preoperative lateral mass displacement averaged 7.3 mm and postoperative displacement had a mean of 2.4 mm with a p value after reduction of < 0.002. No patient had serious complication resulting in neurologic deficit or vascular injury associated with the procedure. No patient went on to develop the previously described “cock-robin” deformity from subluxation of the lateral mass with settling of the occiput onto the C2 lateral mass and no patient had subsequent C1–C2 instability as defined by an ADI greater than 3 mm on flexion and extension films.
Conclusion
Patients with unstable C1 ring fractures can be successfully managed with primary open reduction and internal fixation with a transversely oriented construct using C1 lateral mass screws. Open reduction and internal fixation offers a viable treatment alternative to conservative management or fusion by restoring cervical alignment with C1 reduction and anatomical realignment. Internal fixation of the atlas without fusion prevents progressive, painful deformity, and the need for complex occipitocervical reconstruction procedures that have been reported with nonoperative management of these injuries.