Pedicle Screw Fixation in Cervical Spine
Cervical pedicle screw fixation is an effective procedure for stabilizing an unstable motion segments, as this procedure can offer the strongest stability among several instruments used in cervical spine. However, it has generally been considered too risk
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Yasutsugu Yukawa
Purpose
Planning and Diagnostics
Pedicle screw fixation can provide the strongest stability for cervical reconstruction with potential risk for neurovascular injury. This chapter introduces cervical pedicle screw fixation and describes its indication, surgical procedure, imaging technique, and technical pitfalls in detail.
Pedicle screw fixation can be applied to any kind of unstable lesions or deformity in the cervical spine. They include spinal injuries, kyphotic deformity, and the unstable cases which need reconstruction after resection of spinal tumor. Unstable cervical injuries like as subluxations, dislocations, burst fractures and fracture dislocations, and cervical spondylotic myelopathy with kyphosis >13° are candidates for this procedure. Deformity cases like dropped head syndrome (chin-on-chest deformity) are another candidates for this procedure. In cervical trauma cases, surgical indication is decided with the subaxial injury classification scoring system. Plain X-ray (AP, lateral, two oblique views), computed tomography (CT), and magnetic resonance imaging (MRI) should be obtained preoperatively in all patients. Some cases need flexion-extension X-ray to diagnose the instability and flexibility. It is of paramount importance for the surgeon to review all the preoperative radiographic studies to ensure that no destruction of the pedicle exists that precludes the placement of pedicle screws. Pedicle morphology and medial inclination of the pedicle axis are fully visualized and noticed preoperatively. As the diameter of screw is 3.5 mm at least, the minimum diameter of pedicle should be more than
Prerequisites Pedicle screw fixation can be applied to any kind of unstable lesions or deformity in the cervical spine. This procedure is available at all levels between C2 and C7. However the candidates for this procedure should have intact pedicles at surgical levels. The subjects with pedicle malformation or angiectopia of vertebral artery are relative contraindications for this technique. A fluoroscope is a minimum necessary requirement to obtain entry point and trajectory angle of pedicle screw in cervical spine. The computer-assisted navigation technique might improve the accuracy of screw placement.
Y. Yukawa (*) Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama City, Japan e-mail: [email protected]
© Springer Nature Switzerland AG 2019 H. Koller, Y. Robinson (eds.), Cervical Spine Surgery: Standard and Advanced Techniques, https://doi.org/10.1007/978-3-319-93432-7_68
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3.5 mm. If the fracture line exists within pedicle in trauma case, that pedicle is not suitable for this procedure. CT angiography and MR angiography are necessary to observe the presence of vertebral artery (VA) anomaly or disruption preoperatively. The course and patency of the VA must be clearly delineated to avoid injury to that structure.
Patient Positioning After careful intubation, the patient is placed in prone position on a low-repulsion mattress
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