Objective:To evaluate the treatment efficiency of occipitocervical fusion for occipitocervical instability. Methods:Totally47 patients of occipitocervical instability treated by occipitocervical fusion from August 2007 to April 2014 were reviewed. All the patients including 34 males and 13 females underwent occipitocervical fusion. The average age of included cases was(50.87±14.08)years(ranged from 15 to 77 years). The pre-operative diagnoses was made on 33 cases of atlanto-axial fracture or dislocation by injury

12 cases of congenital occipitocervical anomalies

one case of upper cervical tumor and one case of rheumatoid arthritis.Japanese orthopaedic association(JOA)scale

visual analog symptom rating(VAS)scale

pre- and post-operative radiographic data were used for efficacy assessment. Results:All the cases were followed up for 8 to 88 months

averaged(45.79 ±16.12) months.Forty-six of the total cases showed bony fusion on the postoperative X-ray film. The fusion rate was 97.9%. Mean preoperative JOA score and VAS score were(12.32±2.97)points and(6.55±1.14)points while postoperative were(14.85±2.26)points and(1.91±1.06) points

respectively. There were significant differences between preoperative and postoperative results(t =-15.77

P =0.000;t =52.54

P=0.000). Conclusion:Posterior occipitocervical fusion using the cervical pedicle screws and plate-rod systems is an effective surgical technique for occipitocervical instability and satisfactory fusion status could be achieved with perfect biomechanical stability.