The value of intraoperative ultrasonography in cervical corpectomy: assessment by postoperative computed tomography

We assessed the value of intraoperative ultrasonography (IUS) in cervical corpectomy by using postoperative computed tomography (CT) for comparison. Twenty patients underwent a one-, two-, or three-level cervical corpectomy. The decompression was performed in a stepwise fashion, guided in each case by IUS findings until considered adequate. Each patient underwent postoperative CT to evaluate the accuracy of the IUS in guiding the decompression. In the 20 patients who underwent corpectomy, IUS guided a complete lateral gutter decompression. No evidence of asymmetry and excessive bone removal was identified by IUS at the end of the procedure. IUS was not useful in assessing the adequacy of longitudinal decompression because of the absence of neural landmarks in the sagittal plane. Postoperative CT confirmed adequate decompression in all patients. The width of decompression at the posterior margin of the vertebral body ranged from 18 to 20 mm, with a mean of 19.2 mm. We conclude that IUS is helpful and reliable in performing a properly centered, thorough, lateral decompression in cervical corpectomy. A limited corpectomy can be started under visual guidance and then enlarged after IUS findings until complete decompression of the neural elements has been achieved. This approach avoids the problems of asymmetry, inadequate decompression, and excessive bony removal that could lead to endangerment of the vertebral artery and possible failure of the reconstruction. The accuracy of the IUS was confirmed in this study by postoperative CT.