586 - CT Guided Pre-operative Key Wire Insertion for Pedicle Screws Intra-op...

Oral Posters: Adult Spinal Deformity

Presented by: T. Marnay - View Audio/Video Presentation (Members Only)


T. Marnay

(1) Montpellier Centre de Chirurgie Vertébrale, Spine Department, Castelnau-le Lez, France


Introduction: Pedicular screws is the most used posterior fixation even now in deformities. However it remains challenging especially with inclination and rotation of the vertebras and dysplasia pedicles. Multiple intraopérative guiding systems have been developed with a remaining margin of error non acceptable especially in the rotated thoracic vertebras.We developed a pre-operative CT guides procedure with marking key wires setting in the pedicles selected in the surgical programmation. Those "marks" will guide the cannulated screws during the surgery.

Material and Methods: From october 2014 to december 2015 136 patients who needed a posterior fixation underwent a pre-operative Marking key wire insertion in pre-op by our interventional radiologist, just before the surgical procedure. 97 deformities (94 scoliosis), 32 degenerative spine, 7 fractures. The key wires are let under the skin after the CT scan time and a minimally opening allows to take it off and replace it with a long cannulated screw guide to set the screw itself. The rod placing may be done with a minimally invasive or an open procedure. A CT analysis of each setting is realized.

Results: 1370 marking key wires have been inserted, 100% were in place .4 have been inserted through the transverse process according to a very small size of the pedicle. 5 have not been used during the surgical procedure (accidental removal, or too close of the adjacent level). The capacity of insertion of screw in safety conditions, in the apex of the concavity of thoracic curve have been used in the 59 thoracic scoliosis without any misplacement. The reduction of the incision, of the per-op X-Rays exposure, of the surgical timing (in average less then 3 minutes for each screw during the surgical time), and so the reduction of the bleeding have been measured in each case. An economical analysis has also been conducted.

Conclusion: In patients who request pedicle screws, especially in complex deformities, this procedure cancels the neurologic complications, allows screws setting in all situations with a better mechanical efficiency, reduces the surgical complexity, irradiation, bleeding and timing. Beside all the current expensive systems, this procedure I can be used by all spine departments with an open access to a CT scan and an intern-evntional radiologist.