Effect of surgical treatment for adult fresh type Ⅱ and shallow type Ⅲ dens fractures

English Keywords:Dens fracture  Dens screw  Pedicle screw  Internal fixation

English Abstract:

  【Abstract】 Objectives: To explore the clinical effect of anterior odontoid screw fixation and posterior C1-C2 screw fixation for adult type Ⅱ and shallow type Ⅲ dens fractures. Methods: Between March 2010 and March 2016, 23 consecutive patients(15 males and 8 females; mean age 41.2±15.1 years old, range 15-68) with dens fracture were evaluated retrospectively. There were 17 type Ⅱ dens fracture patients and 6 shallow type Ⅲ dens fracture patients according to Anderson and D′Alonzo classification of odontoid fractures. All patients presented with neck pain and limited neck motion. Neurological deficits were found in 5 patients. Preoperative JOA scores were 10-14 points(mean, 12.8±1.6). 13 patients received anterior odontoid screw fixation while 10 cases received posterior C1-C2 screw fixation and fusion(Harms and Melcher Fixation). Results: None of the 23 patients suffered from any complication such as injury of vessel, nerve or esophagus. All of the 23 patients were followed up for 8 to 30 months with an average follow-up of 18.0±6.4 months. At 6 months after operation, the JOA scores of 5 patients suffering from neurological deficits preoperatively were 14-17 points(mean, 16.3±1.3). The average improvement rate was 83.3%. Postoperative imaging findings revealed that the relative positions of atlantoaxial vertebrae were satisfactory. There was no loosening or fracture of the internal fixation. One patient who received anterior odontoid screw fixation was found nonunion at 8-month follow-up. All the other 12 patients who received anterior odontoid screw fixation achieved solid bony healing. 10 patients who received posterior C1-C2 screw fixation achieved bony healing. Conclusions: Anterior odontoid screw fixation and posterior C1-C2 screw fixation are effective, reliable and safe, which are options for the treatment of adult type Ⅱ and shallow Ⅲ dens fractures.