Clinical effect of clivo-axial angle in posterior approach for patients with unstable upper cervical spine / 中国综合临床

ABSTRACT

Objective To investigate the clinical effect of clivo-axial angle(CAA)in the posterior approach for patients with unstable upper cervical spine.Methods Twenty-one patients with unstable upper cervical spine treated with posterior approach surgery from October 2014 to March 2016 were included in this study,and the patients were divided into the decompression group(11 cases)and the non-decompression group (10 cases)according to whether the intraoperative decompression was included.The clivo-axial angle(CAA) were measured by mobile three-dimensional before and after the surgery in order to estimate the reduction of spinal cord compression effect after the posterior cervical surgery combined with the reduction,fixation and bone graft fusion,then to guide the restoration.CT was used to measure the CAA and MR was used to measure the cervico-medullary angle(CMA)before operation and 3 months after operation.Japanese Orthopedic Association (JOA)scores was used to evaluate the neurological function 6 months after operation.Results All patients were followed up for 6-12 months.CMA((156.3±3.6°)vs.(155.9±2.7°))and CAA((154.3±5.1°)vs. (151.3±4.7°))of the decompression group and the non-decompression group at 3 months after surgery were improved significantly compared with those collected before the surgery(CMA(131.5 ± 0.6°)vs.(131.1 ±0.5°);CAA(133.2 ± 1.7°)vs.(132.4 ± 1.2°)),the differences were statistically significant(CMA t=-21.81,P=0.00 vs.t=-28.54,P=0.00;CAA t=-12.44,P=0.00 vs.t=-11.68,P=0.00).After operation,CAA((152.3 ± 1.3)vs.(132.6 ± 1.5))was significantly improved,compared with that before reduction((131.1±1.9)vs.(132.4±1.5°))(t=-30.09,P=0.00 vs.t=-35.93,P=0.00).JOA scores of the two groups at 6 months after operation((9.8±1.3)points vs.(10.3±1.7)points)were significantly lower than those before the surgery((7.1 ± 0.7)points vs.(7.6 ± 1.1)points),the differences were statistically significant(t=6.01,P=0.00 vs.t=4.36,P=0.00).No complications such as fixed failure,infection,spinal cord injury and vertebral artery injury were found in all patients.Conclusion For patients with upper cervical spine instability,the usage of intraoperative three-dimensional C arm scanning in CAA measurement to determine the effect of spinal cord compression can guide the reduction,simple and feasible,the clinical effect is satisfactory.