Novel Intraoperative Technique to Visualize the Lower Cervical Spine: A Case Series
Visualization of the lower cervical spine with a lateral radiograph poses a challenge secondary to encroachment of the shoulders. Applying traction to the arms or taping the shoulders down provides adequate visualization in most patients, but imaging the mid- to lower cervical levels presents a significant challenge in patients with stout necks. We present a variation of the lateral radiograph that is 30º oblique from horizontal and 30º cephalad from neutral and used in a series of patients with stout necks that require anterior instrumentation of the lower cervical spine. We reviewed intraoperative images of 2 patients who underwent anterior cervical spine surgery at our institution, and assessed type of procedure, body mass index, and outcome scores. Our variation provided improved visualization relative to a lateral view and was used intraoperatively to confirm correct-level hardware placement in both patients.
Lack of visualization can lead to aborted surgeries or, potentially, surgery at the wrong level.3 A 2008 American Academy of Neurological Surgeons survey indicated that 50% of spine surgeons had performed a wrong-level surgery at least once in their career, and the cervical spine accounted for 21% of all incorrect-level spine surgeries.7 Intraoperative factors reported during cases of wrong-level spinal surgeries included misinterpretation of intraoperative imaging, no intraoperative imaging, and unusual anatomy or physical characteristics.8 Such complications can lead to revision surgery and other significant morbidities for the patient.
In most patients, fluoroscopy allows confirmation of the correct level before disc incision.3 However, operating at a lower cervical level in a patient with a short neck or prominent shoulders poses a significant problem.3 A case report from Singh and colleagues9 described a modified intraoperative fluoroscopic view for spinal level localization at cervicothoracic levels. Their method focuses on identifying the bony lamina and using them as landmarks to count spinal levels, whereas our 30º–30º oblique image is useful for confirmation of adequate hardware placement during anterior cervical spinal fusions. Often, the initial localization of cervical vertebral levels can be achieved with a standard lateral radiograph. We recognized the utility of the 30º–30º oblique view when we were attempting to visualize the inferior aspect of the plate and inferior screw placement.
In patients with stout necks, a lateral radiograph may show only visualization down to C4 or C5.3 Even with applying traction to the arms or taping the shoulders down, it can be impossible to visualize C6, C7, or T1 because the shoulder bones and muscles obstruct the image.3 Using a 30º–30º oblique view, we were able to obtain adequate visualization and assess the accurate placement of hardware.
Conclusion
A 30º oblique view from horizontal and 30º cephalad from neutral radiograph can be used intraoperatively in patients with challenging anatomy to identify placement of hardware at the correct vertebral level in the lower cervical spine. It is a noninvasive technique that can help reduce the risk of wrong-site surgeries without prolonging operation time. This technique describes an alternative to the lateral radiograph and provides a solution to the difficult problem of intraoperative imaging of the mid- to lower cervical spine in 2 adequate planes.
