Posterior Atlantoaxial Nonfusion Operation For Odontoid Fractures

Objective:To evaluate the clinical effect of posterior atlantoaxial nonfusion pedicle screw fixation in the treatment of odontoid fracture,to prove that the posterior atlantoaxial nonfusion pedicle screw fixation is available and of good result and to summarize it's indications.Methods:From January 2005 to September 2013 in the spine surgery department in the first affiliated hospital of Anhui medical university of Orthopedic Department,10 patients diagnosed with type?C odontoid fracture were retrospectively analyzed.Cervical X-ray,CT scanning and MRI were taken to confirm the fracture and the classification.All of them were treated with posterior atlantoaxial fixation without bone graft fusion.The postoperative X-ray and CT were taken to ensure perfect internal fixation.According to radiological examination,the internal fixation instruments were removed through secondary operation when bony fusion of the den was obseraved during followup.Then the rotary function of atlantoaxial joint was evaluated.Results: C1/2 pedical screws were successfully inserted in 10 patients.Anatomical reduction was achieved without injuries of veterbral artery and spine cord.All patients were followed up for an average period of 18 months(range12~30months).Bony fusion was observed on radiological examination at last follow up,the cervical ROM ranged from 30°~55°(average 45°).After secondary operation,the cervical ROM(range of motion)ranged from 50°~70°(average 60°).In the following 3-6months,the ROM was 80° ~90°(average85°)which was almost normal.Conclusions:Posterior atlantoaxial pedicle screw fixation without fusion is safe and desired operation method in treatment of fresh odontoid fracture especially for type ?C fracture.It can not only achieve anatomical reduction,restore atlantoaxial relation,attain stable 3D fixation effect immediately,but also greatly preserve the C1/2 rotation function when the internal fixation is removed.This operation method has extensive indications,can act as a remedial measure when anterior screw fixation failed.