Transdiscal C7 Pedicle Subtraction Osteotomy With a Strut Graft and the Correction of Sagittal and Coronal Imbalance of the Cervical Spine

Abstract

BACKGROUND Cervical spine deformity negatively affects patients’ quality of life. Pedicle subtraction osteotomy (PSO) has reported to correct cervical deformity but it is challenging and carries a significant risk of morbidity. OBJECTIVE To report transdiscal C7 PSO with a strut graft for the correction of sagittal and coronal imbalance in patients with fixed cervical deformity. METHODS After standard exposure, the spine was instrumented from C2 to T3. T1 subtotal laminectomy, and C6 to C7 total laminectomies were necessary for C7 PSO. Osteotomy was initiated with removal of C6–7 and C7–T1 facet joints to isolate C7 pedicles and identify bilateral C7/C8 roots. Bilateral C7 pediculectomies and transdiscal PSO were performed. A rectangular strut allograft was then inserted into the PSO site. The location of the strut graft was used as a fulcrum of sagittal and coronal correction. The head fixator was released and the head was extended under intraoperative neuromonitoring, and then detailed sagittal and coronal balances were controlled by compressing or distracting between the pedicle screws above and below the osteotomy. RESULTS This technique was applied in 2 patients with fixed subaxial cervical deformities. Transdiscal PSO could add more amount of correction and provide the additional fusion surface. The strut graft prevented sagittal translation, foraminal narrowing, and excessive focal cord kinking during PSO. Both patients showed radiologic and clinical improvements after surgery, and no neurovascular complication occurred after the surgery. CONCLUSION Transdiscal C7 PSO with a strut graft placement provided a safe way of correcting sagittal and coronal imbalance simultaneously and reduced neurological complication by preventing sagittal translation, foraminal narrowing and spinal cord kinking.

Safety and Efficacy of Intraoperative Doppler Sonography-Assisted Cervical Pedicle Screw Fixation—A Retrospective Comparison with Conventional Pedicle Screw Implantation

“…For example, when it is challenging to change screw trajectory for long pedicle screw implantation, a short paravertebral foramen screw can be placed instead to avoid the VA injury, and the length of this screw can be accurately determined using intraoperative Doppler sonography. 19 , 20 …”

SOF System; A New Nomenclature System for the Surgical Techniques of Cervical Spine Deformity

“…However, surgical correction of CSD can be challenging not only because it often requires osteotomies to obtain adequate correction especially in the setting of rigid CSD, but also because the target of surgical correction is adjacent to the critical neurovascular structures. 8,[10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] Thus, the postoperative complications have been reported to be relatively high and the number of studies on CSD are far inferior to those of thoracolumbar deformity.…”