OBJECTIVETo explore the effects of posterior transarticular fixation with rod-screw in treating fracture and dislocation, spinal stenosis of lower cervical vertebrae.

METHODSFrom July 2005 to July 2009,11 patients with cervical fracture and dislocation and 9 with spinal stenosis of lower cervical vertebrae underwent operation with transarticular fixation with rod-screw (Vertex system). There were 16 cases male and 4 cases female, ranging in age from 29 to 76 years with an average of 51 years. All patients underwent decompression,internal fixation and fusion through posterior approach (combined with anterior approach in 3 cases). The method of insertion of screw: the starting point located in medial 1 mm of the midpoint of the lateral mass, angle in sagittal plane was 15 degrees-20 degrees of caudal clinism and in coronal plane was 35 degrees-40 degrees of external clinism. The position of screws, the cervical array, bone graft and fusion were observed by X-ray films.

RESULTSA total of 88 transarticular screws were successfully inserted, 10 screws located in C3,4, 20 in C4,5, 32 in C5,6, 26 in C6,7. There were no complications related to screw insertion, such as injury of the vertebral artery, nerve roots and the spine cord. All patients obtained bone fusion without internal fixation breaking. The improvement rate of JOA was 55.8% at the 1st week after operation, 5 cases got excellent results, 7 good, 7 fair, 1 poor; the improvement rate of JOA was 74.5%, at the 3rd month after operation, 6 cases got excellent results, 8 good, 6 fair. There was significant difference in the JOA between before operation and at the 3rd month after operation.

CONCLUSIONThe transarticular screw fixation with rod-screw in the lower cervical spine is an effective fixation, which has advantages of rigid stability, convenience to perform, and can reduce operative risk in initial application, but the long-term follow-up is very necessary.