ABSTRACT
BACKGROUND:At present,there is a lack of an internal fixation system with good reduction and simple operation for the treatment of atlas burst fracture by posterior single-segment fixation. OBJECTIVE:Based on the atlas CT measurement data,a new posterior atlas fracture reduction and internal fixation system was designed and optimized,which was in line with the characteristics of human local anatomical structure,easy to operate and with good reduction. METHODS:CT images of 347 adults were analyzed retrospectively.In the images,the length of pedicle screw track with a medial inclination of 0°,the angle of the maximum medial inclination angle and the length of pedicle screw track at this time,the height of vertebral artery groove,the distance between the entry points of bilateral pedicle screws and the midline,the radius of the posterior arch of atlas,the distance between the posterior tubercle of the atlas and the posterior edge of the foramen magnum,and the distance between the posterior tubercle of the atlas and the upper surface of the axial arch were measured.The imaging data were analyzed and a reduction and internal fixation system was designed and optimized for atlas fracture in line with human anatomical characteristics. RESULTS AND CONCLUSION:(1)There was no statistically significant difference in the the length of pedicle screw track with a medial inclination of 0°,the maximum medial inclination angle and the length of pedicle screw track at this time,the height of vertebral artery groove,the distance between the entry points of bilateral pedicle screws and the midline,the radius of the posterior arch of atlas,the distance between the posterior tubercle of the atlas and the posterior edge of the foramen magnum,and the distance between the posterior tubercle of the atlas and the upper surface of the axial arch measured on the left and right sides of all subjects(P>0.05).There were statistically significant differences in each index measured between the male and female groups(P<0.05).(2)The new posterior atlas fracture reduction and internal fixation system has been successfully designed and obtained the national patent.The internal fixation system is suitable for the anatomical characteristics of the posterior arch of the atlas.It can not only effectively treat the atlas burst fracture,but also retain the movement function of the occipital atlantoaxial joint.
ABSTRACT
BACKGROUND:Previously, serious thoracolumbar burst fractures with spinal cord injury were mainly treated by anterior surgery. The superiority of conventional posterior repair lies in strong reduction and fixation effects. However, it is difficult to fuly decompression. The anterior and central cylinders of the injured vertebra cannot receive good reconstruction. Loss of correction and internal fixation failure always appear. It remains controversial which repair method is more ideal. OBJECTIVE:To comparatively analyze the effect of posterior and anterior approaches with subtotal vertebrectomy, decompression, reconstruction of spine, and internal fixation for patients with thoracolumbar burst fractures. METHODS: The data of 42 patients with thoracolumbar burst fracture treated by anterior and posterior approaches with subtotal vertebrectomy, decompression, and reconstruction of spine from May 2006 to December 2012 was retrospectively analyzed. They were divided into two groups according to the surgical procedures: anterior approach group (n=23) and posterior approach group (n=19). They were folowed up for at least 24 months. Repair results and imaging results were compared in patients of both groups. RESULTS AND CONCLUSION:None patients in the two groups affected fixator loosing or breakage, and obtained good bone fusion. The intraoperative blood loss was more and operative time was longer in the anterior approach group than in the posterior approach group, showing significant difference (P 0.05). No significant difference in the anterior vertebral height and kyphosis Cobb angle was detected before treatment, at 1 week after treatment and during final folow-up (P > 0.05). The incidence of postoperative complications was significantly higher in the anterior approach group than in the posterior approach group (P < 0.05). These findings confirm that subtotal vertebrectomy through anterior approach and posterior approach can effectively repair thoracolumbar burst fractures. However, the complications of posterior approach are less, and posterior approach has few impacts on the pulmonary function, is safe, and has good biocompatibility with the host.