ABSTRACT
ObjectiveTo analyze the risk factors related to perforation of lateral wall by lower cervical pedicle screw instrumentation in the treatment of cervical spinal disorders. MethodsA retrospective review was made to analyze 214 cervical vertebral injury patients ( 1 024 pedicle screws were used) treated with pedicle screw instrumentation at C3-7 from July 2004 to July 2009. Lateral walls of 18 patients were perforated (a total of 28 pedicle screws). The surgeons assessed the position and the angle of the screw in the pedicle, and the relation and the distance between the screw and the pedicle walls by carefully probing intraoperative walls of cervical pedicles and studying postoperative thin-slice computed tomography (CT) scan of the fixed vertebral segments of the cervical spine. The data of patients with lateral wall perforation was recorded and analyzed statistically. ResultsPerforation of the lateral wall occurred in 18 patients (28 pedicle screws). Backward step by step Logistic regression analysis was used and two variables were selected in the end. ConclusionsRatio variance between inner and lateral wall is the risk factor of perforation in the lateral wall associated with lower cervical pedicle screw instrumentation, while the angle variance between implanted screws and CT measurements is the protection factor of perforation in the lateral wall.
ABSTRACT
Objective To analyze the complications of lower cervical pedicle screw fixation in treatment of the cervical spine disorders and discuss the operative technique. Methods A retrospective study was made in 104 patients with different cervical injuries treated by C3-7 pedicle screw fixation (total use of 624 screws) from July 2004 to March 2008. One stage posterior reduction and fixation using lower cervical pedicle screw-rod system or screw-plat system were performed in 66 traumatic patients and the nerve condition was evaluated by Frankel criteria system. For 46 non-traumatic patients, laminoplasty or laminectomy was performed for decompression, and cervical pedicle screw-rod system or screw-plat system were used in deformity correction and stability reconstruction. Based on exploration to quadric walls of vertebral pedicle during operation, postoperative thin-slice CT scan along operative vertebra segments' pedicle and bilateral oblique position X-ray of cervical spine in all patients, we evaluated screw location, screw angle as well as the distance and the relation between the screws and the internal pedicle wall or lateral wall. Results In this study, the lower cervical pedicles of 104 patients were fixated with 624 screws including 77 screws (12.34% ) for pedicle wall damage, 68 screws (10.8% ) for the lateral wall injury, 56 screws (8.97% ) for grade Ⅰ violation of pedicles, 12 screws (1.92% ) for grade II violation of pedicles Ⅱ violation of pedicles and 9 screws (1.44% ) for inferior wall injury of cervical pedicle. The follow-up lasted for 3-24 months (average 9. 8 months), which showed breakage of two screws (0.32% ) and loosening of one screw (0.16% ). Conclusions Lower cervical pedicle screw fixation has relatively low incidence of complications and is a safe operation. The complications can be minimized by sufficient preoperative imaging studies of the pedicles, familiar with the feature of opography and reasonable surgery technique.
ABSTRACT
[Objective]To recommend the detailed operative skill of lower cervical transpedicle screw and peri-operative experience.[Method]From July 2004 to April 2006,based on anatomical research of cadaver,15 cases involved lower cervical had been treated by transpedicle screws and plate or rod,which assisted in fluoroscopic moniter.Lateral mass needed be revealed completely,thus basilar part of superior articular process could be recognized.The central point of screw inserted were laid on the surface of lateral mass: 5mm inner to the outside border of lateral mass;3mm below to the inferior of superior articular process.Ball-like burr was used to de-cortical.Made a pathway with 2 mm hand-drill paralleled with the upper end-plate cartilage of the vertebra and maintain abduction angle about 40?～45? with middle line of the vertebra,self-designed pedicle probe was used to ensure safety tunnel of cancellated bone.3.5 mm cortical screws were adoption and thread was not recommend.[Result]Eightysix lower cervical pedicle screws had been inserted successfully in C3～7 vertebra,exclude a failed C4 screw.Average screws length was(26 + 1.6)mm and abduction angle based on postoperative CT scan was 37.9??5.4?.Abundant bleeding was occurred while built the pedicel pathway in 2 screws,and there were 6 screws showed perforation of the pedical wall refer to postoperative CT scan. No evidence indicated the complication about injury of vessel or nerve structure.[Conclusion] The technique of lower cervical transpedicle screw are relatively safet.Successful screw insertion depends on subtile sense of operation doctor's hand.