Reconstruction using implants compatible with MRI for malignant spine tumors

It is necessary to resect malignant spine tumors aggressively and to subsequently reconstruct the spinal column. The Diapason screw and hook system, which is compatible with magnetic resonance imaging, has been used recently for reconstruction. This study included 17 patients (5 with primary tumors and 12 with metastatic tumors) who underwent excision and reconstruction with the Diapason screw and hook system. The surgical procedures performed were circum-spinal decompression by posterior extensive curettage in 12 cases, and en bloc total spondylectomy in 5. The follow-up periods ranged from 6 to 28 months. Though paralyses of Frankel grade B in 2 patients were not improved, paralyses of Frankel grade C in 10 cases and Frankel grade D in 4 cases improved to Frankel grade D or better postoperatively. MRI was performed to detect recurrences during the follow-up period. Recurrence of paralysis occurred in 5 patients. MRI could disclose recurrences of tumors in these patients because there were fewer signal loss artifacts in these implants than are found in those made of stainless steel alloy. For detecting recurrences, the Diapason system was satisfactory in the MRI follow-ups.