Erich Salomonowitz MD, Presenter: Nothing to Disclose

Wilma van der Riet, Abstract Co-Author: Nothing to Disclose

Andreas Stadlbauer PhD, Abstract Co-Author: Nothing to Disclose

Knut Eberhardt, Abstract Co-Author: Nothing to Disclose

Static MR protocols do not evaluate functional instability of cervical segments. This study demonstrates the value of MR-fluoroscopy with a dedicated positioning device in the assessment of hypermobility and instability associated with cervical disc surgery.

Fifty-four patients with unisegmental lower c-spine disc hernias were examined during active ante- and retroflexion at one week pre- and six months postoperative in a 3 T MR system (Trio, Siemens). A dynamic positioning system was used allowing for continuous controlled movement of the patient´s head and c-spine (NeuroSwing, Inside Inc.) with 3D Haste, True Fisp, T1/T2w TSE, and 40 sec real-time sequences. In-plane resolution was 0.3 – 2.0 mm. Individual ranges of motion were assessed preoperatively and served as postoperative benchmark.

Of the 54 patients, 11 (20.4 %) had a hypermobile segment adjacent to the segment with the disc hernia. Three patients demonstrated compression of the cervical myelon during motion. In all these patients, surgical strategies were changed, i.e. upgraded to receive two extra longitudinal anterior intervertebral plates bridging the cage within the diseased disc. All other patients had no extra operation. At postoperative dynamic examinations, all segments were stable within the individual ranges of motion. There were no complications resulting from the active motion device.

Dynamic evaluation of c-spine disc hernias has a major impact on surgical and anesthetic stategies, significantly improving functional outcome by the preoperative detection of instability or compression of the myelon in adjacent segments by motion. MR at 3T allows for high spatial and temporal reolution, cine and still picture analysis for exact definition of motion allowances.

Salomonowitz, E, van der Riet, W, Stadlbauer, A, Eberhardt, K, Cinematographic MRI of the Cervical Spine before and after Cervical Disc Surgery Using a Standardized Positioning System at 3 Tesla.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4409894.html