Surgical technique for correction of sagittal translation using V-shaped rod repositioning and lifting reduction in ankylosing spondylitis kyphosis

A total of 29 patients with severe kyphosis deformity secondary to ankylosing spondylitis underwent posterior spinal osteotomy from October 2017 to April 2023, with intraoperative ST occurring in 7 cases. The primary surgical modification involved the application of V-shaped cobalt-chromium-molybdenum (CoCrMo) alloy rod and changing its place position in the pedicle screws for create displacement between rod and screw, subsequent locking of the screw facilitated a lifting reduction, ensuring accurate alignment and minimizing vertebral displacement. Clinical and radiographic data were collected for all 29 patients. Patient-Reported Outcome were assessed using Oswestry disability index(ODI) and the Scoliosis Research Society-22 (SRS-22) questionnaire for comparative analysis in addition. A total of 29 patients successfully underwent surgery. There were no significant differences in general characteristics between the 7 patients who experienced ST and the 22 patients who did not. Both groups showed significant improvements in sagittal alignment postoperatively, though no significant differences were observed between them. In the ST group, the global kyphosis (GK) improved from 88.3° ± 15.0 to 28.9° ± 20.7, Pelvic tilt(PT) decreased from 34.5°± 20.0 to 18.5° ± 12.8,while in the non-ST group, GK improved from 86.6° ± 28.1 to 30.9° ± 23.0, PT improved from 34.3° ± 15.5 to 26.1° ± 12.5. STs were corrected from 5.4mm ± 1.3 to 1.0mm ± 1.3, with no patients experienced neurological complications postoperatively. ODI improved from 42.6 ± 15.2 to 16.3 ± 7.2 in the ST group, and from 52.5 ± 12.6 to 22.6 ± 11.7 in the non-ST group. SRS-22 scores improved from 10.9±1.7 to 13.8±1.7 in the ST group, and from 10.3±2.6 to 13.9±1.9 in the non-ST group, both improved significantly. The novel surgical technique, utilizing V-shaped CoCrMo rod repositioning within the pedicle screw construct and subsequent lifting reduction, is a safe and effective approach for correcting ST in patients with kyphosis deformity secondary to ankylosing spondylitis.