Transcutaneous sonography of the postoperative spine.

Transcutaneous sonography of the spine was performed in 83 patients with prior laminectomies for tumors of the spinal canal and the spinal cord. These patients presented with signs or symptoms of recurrent tumor. When the spinal cord could be visualized, the sonographic examination provided information about the presence or absence of tumor, the character (solid or complex) of the tumor and its location, and associated findings in the extramedullary space. The correlation of the transcutaneous sonograms with other imaging methods and with intraoperative sonographic and surgical findings was excellent. Nonvisualization of the spinal cord was found to be related to age with a higher success rate (70% visualized) in the pediatric age group (to age 21) than in the adult group (52% visualized). A very short laminectomy was also found to cause problems in visualizing the full extent of a recurrent tumor. Nonetheless, the simplicity of the technique and the amount of information that can be gained from it make it a very valuable adjunct to other imaging methods for the postoperative spine. For the pediatric age group, it should be one of the first diagnostic methods employed.