Application of Unilateral C2 Translaminar Screw in the Treatment for Atlantoaxial Instability as an Alternative or Salvage of Pedicle Screw Fixation.

ABSTRACT

OBJECTIVE: To analyze the clinical outcomes of our experience with the unilateral C2 translaminar screw technique and evaluate its feasibility as an alternative or salvage of the pedicle screw. METHODS: Eleven consecutive adult patients with atlantoaxial instability who underwent hybrid fixation techniques using unilateral translaminar screw combined with contralateral C2 pedicle screw and bilateral C1 LMS via posterior arch from January 2010 to December 2013 were retrospectively investigated. The surgical techniques and treatment procedures were described, and clinical symptoms, neurologic function, and imaging appearance were evaluated. RESULTS: The average age in our series was 40.9 years. No vascular or neurologic injuries occurred. No hardware failure or breach of C2 lamina or pedicle was observed in postoperative radiographs or computed tomography scans. Good bone union was achieved in all patients. There were no cases of screw pullout or pseudarthrosis. CONCLUSIONS: Patients with variant vertebral artery or osseous anomaly are good candidates for the hybrid translaminar screw technique as an alternative to or salvage of C2 pedicle screw.