Correction of Cervical Kyphosis Using Pedicle Screw Fixation Systems

Purposes: Correction of cervical kyphosis has been one of the challenging problems in the field of spinal surgery. The purposes of this report are to investigate the clinical results of correction of cervical kyphosis using pedicle screw.

Materials and Methods: Until February 1999, 49 patients with cervical kyphosis were treated using pedicle screw fixation systems. Their average cervical kyphosis was 29.7° (range: 15°-68°) Causes of kyphosis were old cervical spinal injury in 14 patients, subaxial lesion of RA in 13, cervical spondylosis in 14, postlaminectomy kyphosis in eight, and others in four. Pedicle screw-plate or screw-rod system for the cervical spine was used in 46 patients and occipitocervical rod systems were in three patients. In 32 patients (Group I: average preoperative kyhosis was 27.7°; range 15° to 45°), flexible kyphosis was corrected by posterior surgery alone. Remaining seventeen patients (Group II: average preoperative kyphosis was 31.0°; range 15° to 68°) required additional anterior surgery for correction of their rigid kyphosis or anterior spinal cord decompression. Twenty-three of 49 patients underwent supplemental posterior decompression of the spinal cord or nerve root. For correction of kyphosis, compressive force was applied between the inserted screws after bilateral partial facetectomies.

Results: Fusion was achieved in all patients, and kyphosis in 49 patients was corrected to 3.0° in average. Kyphosis was corrected to 4.8° in average (range:-10° to 32°) in Group I, and to 0.3° in average (range:-10° to 16°) in Group II. Loss of correction was within 3° in all patients. Preoperative neurologic disturbance in 37 patients improved after surgery to some extent. There were three patients with transient nerve root complications related to pedicle screw instrumentation. There were no instrumentation failure.

Discussion and Conclusion: In this series, the greater internal stabilizing capability and pullout strength of pedicle screw provided effective correction of cervical kyphosis. Combined anterior and posterior vertebral osteotomy is effective to correct fixed kyphosis. In addition, this procedure does not require the lamina for fixation anchor, thus, posterior stabilization and correction of the cervical kyphosis can be performed with simultaneous posterior decompression procedure.