INTRAOPERATIVE ULTRASONOGRAPHY IN THORACOLUMBAR FRACTURES WITH INTRASPINAL BONE FRAGMENTS - EVALUATION OF CANALAR STENOSIS AND ANATOMIC CHECK OF DECOMPRESSION - COMPARATIVE-STUDY WITH THE CT-SCAN

Intraoperative ultrasonography is recommended for operations on the th oracolumbar spine to complement the information provided by standard X -ray, intensifier screen or myelography. There are no unanimates opini ons concerning the impaction or exeresis of these fragments. The aim o f this study was to show the advantages of intraoperative ultrasonogra phy for anatomic determination and control of the maneuvers used. This study included 46 cases with fractures from T11 to L2. Ultrasonograph y was performed during the intraoperative reduction provided by the in stallation and the pedicular instruments. The authors stress the limit s of the anatomic and geographic determination, as well as tilting of the fragments because of the size of the ultrasonographic head. The qu ality of the exeresis may be falsely interpreted in the presence of fr agments with a section of less than 4 mm, lateralized, double fragment s or in the presence of massive intraoperative haemorrhage. Analysis o f the impaction results is more complicated because all of these fragm ents displaced themselves secondarily. The ligamentum communis vertebr alis posterior has no anatomical containing role. The tilting before t he impaction and the state of the overlying intervertebral disk repres ent essential factors for failures. Ultrasonography is better than int raoperative myelography. Nevertheless, it still needs to be complement ed by intraoperative profile X-rays and a very precise preoperative CT scan of the intervertebral disk lesions analysis of complicated cases (fragments with residual pedicular attachments - type A 3.1.2.; T-lik e fractures - type A 3.2.1).