Function-preserving reduction and fixation of unstable Jefferson fractures using a C1 posterior limited construct
【摘要】：正Study Design.Retrospective study with clinical and radiologic evaluation of posterior compression reduction and osteosynthesis of C1 in the treatment of unstable Jefferson fractures. Objective.To describe a new concept and surgical technique in the treatment of this previously described injury,which preserves the motion of upper cervical spine,avoiding fusion. Summary of Background Data.The management of unstable Jefferson fractures remains controversial.The majority of C1 fractures can be effectively treated nonoperatively with external immobilization unless there is an injury to the transverse atlantal ligament.Conservative treatment usually involves a long time of immobilization in Halo-vest,whereas surgical intervention generally performs fusion,eliminating the range of motion of upper cervical spine.We propose a new method for the treatment of unstable Jefferson fractures aimed at avoiding these problems. Methods.A retrospective review of twelve patients with C1 fractures between April 2008 to October 2011. Twelve patients with unstable Jefferson fractures were surgically treated via inserting bilateral posterior C1 pedicle screws or lateral mass screws interconnected by a transversal rod internal fixation without fusion. There were eight males and four females with the average age of 35.6 years(range,20-60 years).All patients complained of neck pain,stiffness,and decreased range of motion without neurologic injury.Seven patients had bilateral posterior arch fractures associated with unilateral anterior arch fractures(posterior 3/4 Jefferson fracture,Landells typeⅡ),and five had unilateral anterior and posterior arch fractures(half-ring Jefferson fracture,Landells typeⅡ).Seven patients had intact transverse ligament,and five patients had fractures and avulsion of the attachment of transverse ligament(Dickman typeⅡ). Results.A total of 24 screws were inserted in this group.Three cases had screws placed in lateral mass due to posterior arch breakage,and the height of posterior arch at the entry point less than 4 mm in two cases.The remaining seven cases had pedicle screw fixation.One patient had veniplex injured while exposing lower margin of posterior arch,then gelatin sponge was used for hemostasis.No spinal cord or vertebral artery injury during surgery was found.Postoperative X-ray and CT scan showed partial entry of pedicle screw into vertebral artery foramen in one case,and inside cortex rupture of pedicle caused by screw displacement in one case,but no neurovascular injury was observed.The remaining screws were in good position.All patients were followed up for 6-40 months,22 months on average.All cases were completely painfree,and the range of motion of the cervical spine returned to pre -injury level 3-6 months after surgery.At 6 months follow-up,plain radiographs,and CT scan revealed satisfactory cervical alignment,no implant failure,and bony fusion of the fractures;no C1-C2 instability was observed on the flexion-extension radiographs. Conclusion.C1 posterior limited construct is a valid technique and feasible method for treating unstable Jefferson fractures,which can well preserve the function of the craniocervical junction,with a low morbidity rate.