Posterior Atlanto-Axial Stabilization using Laminar Hooks:Experience of 20 Cases

Background: Trauma is a common cause of C1-C2 instability. Treatment of atlantoaxialinstability is aimed at stabilization, bony fusion, improvement of neurological status andrestoration of normal anatomy. Various surgical techniques were described including;Transarticular and transpedicular screws, laminar hooks, and sublaminar wiring.Objective: Determining the outcome of C1-C2 fixation with posterior laminar hooksystem for treatment of C1-C2 instability, concerning the clinical picture and rate offusion. Patients Methods: Twenty patients assigned for C1-C2 fusion for nonneoplasticcauses were included. Patients were assessed clinically and radiologicallybefore and on second day after surgery. Patients were followed up for a period of 6months. All patients were operated upon by posterior laminar hooks with bony grafting.Results: Postoperative imaging showed proper reduction and alignment in all cases. Inthe last follow up, there was evidence of bone fusion in thirteen cases (65%), while therest of cases showed proper hook positions with no movement on dynamic images.Postoperative clinical evaluation revealed significant improvement of neurological ASIAgrading in 90% of cases, while two patients (10%) had persistent upper limb weakness.Conclusion: Posterior C1-C2 fixation using sublaminar clamps is a technically simpletechnique with high success rates of fusion and clinical improvement. The maindisadvantage of this technique is the need for intact posterior bony elements.