The effect of trausarticular screws combined with lateral mass screws or pedicle screws fixation in the lower cervical spine

Abstract

Objective To discuss the effect of transarticular screws combined with lateral mass screws or pedicle screws through posterior approach in the lower cervical spine. Methods From February 2003 to October 2007, 22 patients were treated using transarticular screws internal fixation combined with lateral mass screws or pedicle screws in Axis plating system and Vertex system. There were cervical fracture and dislocation in 13 patients, ossification of the posterior longitudinal ligament in 4, cervical canal stenosis associated with dentoid process fracture in 1, and cervical disc herniation associated with cervical stenosis in 4 patients. Lamina or facet bone grafting were used to achieve a long-term stability, with decompression and anterior approach or not. The starting point for screw insertion was located 1 mm medial to the midpoint of the lateral mass and the direction of the screw was 40° caudally in the sagittal plane and 20° laterally in the axial plane. Results All screws insertion was successful. A total of 45 transarticular screws were inserted, with 2 in C4,5, 39 in C5,6 and 4 in C6,7. A total of 12 lateral mass screws were inserted, with 6 in C3 and 6 in C4. A total of 41 pedicle screws were inserted, with 4 in C2, 2 in C3 and 6 in C4, 21 in C7 and 8 in T1. There was no complication related to screw insertion, such as injury to the vertebral artery, nerve roots or spine cord. The follow-up period ranged from 10 months to 3 years and 8 months (mean 17 months). All cases got bone fusion. Only one instance of screw partial backout was identified, but fusion was achieved in all pa-tients. In the follow-up period, only one instance of screw partial backout was identified, but fusion was achieved in all patients. Conclusion The combined use of transarticular screws and lateral mass screws or pedicle screws fixation in the lower cervical spine can enlarge the advantages of strong stability,relatively simple, and reduce operating risk when performed appropriately. Key words: Cervical vertebrae; Internal fixators; Bone nails