One-stage anterior-posterior decompression and internal fixation for severe fracture-dislocation of lower cervical spine in "beach chair position"

Abstract

Objective To explore the surgical feasibility and clinical efficacy of one-stage anterior-posterior approaches in treatment of severe fracture and dislocation of lower cervical spine in beach chair . Methods Sixteen male cases of severe fracture and dislocation of lower cervical spine and with a mean age of 49.8 years (range, 36-78 years) treated surgically from May 2012 to May 2016 were analyzed retrospectively by using case series study. The segment of injury was C4-5 in 4 cases, C5-6 in 7 and C6-7 in 5. The degree of spinal cord injury according to the American Spine injury Association (ASIA) score was Grade A in 4 cases, Grade B in 7 and Grade C in 5. Sub-axial injury classification (SLIC) score was 8 points in 9 cases and 9 points in 7. After a general anesthesia, a ring with a hole was hanged on patient's head before the operation. Then, under the protection of hole traction, the upper of operating bed was swung up slowly, so that the patient was restricted in vertical beach chair with traction on the halo in order to immobilize the head and partially reduce the kyphotic deformity. Routine cervical anterior-posterior approach was done with the exposure of damaged section of the front and rear structure. Pedicle screw system or lateral mass screw displacement was conducted. Anterior intervertebral discectomy or fracture vertebral was performed, using collaborative reset prying method before and after the road. In the front of intervertebral cage or titanium net support bone graft, rear pedicle screws or lateral mass screws fixation and bone graft fusion were implemented. The operation time and blood loss were recorded. The healing of the wound was observed. The recovery of neurological function was evaluated according to the ASIA grade. Postoperative review X-ray, CT and MRI were done to evaluate the reset and bone graft in position and fusion. Results All the surgeries were done well without aeroembolism and other related complications. The mean operative time was 153 minutes (range, 150-180 minutes), and the mean amount of blood loss was 543 ml (range, 400-800 ml). Sixteen cases were followed-up from 6 to 24 months (mean 13.7 months). All the incision were healed at I stage. Spinal cord function did not aggravate. The ASIA grade was improved with an average of one to two Grades 6 months after surgery. Postoperative X-ray and CT confirmed that graft object position was favorable and cervical sequence was recovered well. The Cobb angle decreased from (23.6±5.3)°preoperatively to (4.0±0.4)°postoperatively, and the translational displacement of vertebral body was restored into (2.7±0.4)mm (P<0.01) from (10.9±1.6)mm before operation. The cervical spinal canal was not obstructed and the cervical spinal cord was relieved, showed by MRI. Conclusions One-stage anterior-posterior approaches for severe fracture and dislocation of lower cervical spine circumferential reconstruction in beach chair is a beneficial and effective method, without the need of changing positions in a collaborative reduction and fixation. The method can reduce the interference of spinal cord, shorten the operation time and save anterior extra fixation. Key words: Cervical vertebrae; Spinal fractures; Dislocation; Beach chair position