Posterior Single-segment Pedicle Screw For Unstable Atlas Fractures

Objective:To investigate the effect of single posterior pedicle screw in the treatment of unstable atlas fractures.Methods:Clinical data of 14 patients with unstable atlas fractures admitted from July 2017 to September 2020 were retrospectively analyzed.All patients underwent posterior open reduction and internal fixation using a single-segment pedicle screw-rod system.Access to records and preoperative and postoperative X ray film,and through the preoperative and postoperative CT scan,according to Spence standards,mouth slice atlas on both sides of the piece of the sum of displacement of 6.9 mm or judged to be unstable atlas fracture,at the same time clear fracture type,and to assess the fracture,the last follow-up:cervical flexor through a slice to assess whether atlanto-axial joint stability.Results:The mean age of the 14 patients was 51.8 years,and all the patients were successfully operated.The mean follow-up was 21.0±6.4 months.The postoperative review showed that the internal fixation position was good and the reduction was good in the open cervical spine,lateral cervical spine and three-dimensional cervical spine.None of the patients in this study had any surgery-related complications such as massive bleeding,wound infection and internal fixation prolapse.The visual analogue score decreased from6.5±1.3 before operation to 1.9±0.8 after operation(P<0.05).NDI score decreased from 74.4±4.5 before operation to 12.1±4.3 at the last follow-up(P<0.05).At the last follow-up,cervical flexion and extension ranged from 70° to 88°(79.7±6.0);Left and right cervical flexion 76°-85°(82.1±2.8);Left and right rotation 129°-155°(143.5±8.4),and all patients recovered well in the range of cervical motion at the last follow-up,and no imaging findings of atlantoaxial instability were found in the cervical hyperextension and flexion radiographs taken at the last follow-up.After surgery,4 patients complained of neck stiffness with limited movement,which basically returned to normal level under standardized rehabilitation and guided treatment.Conclusion:Posterior single-segment pedicle screw internal fixation for the treatment of unstable atlas fractures greatly reduces the operative time,the amount of blood loss,the probability of complications,the reduction effect is better,and more importantly,the patient’s neck flexion,extension and rotation function is basically not limited.For C1 fractures,transverse ligament rupture may not be contraindicated for open reduction and internal fixation,but the long-term effects of C1-C2 instability remain to be investigated.