Expanded eggshell procedure combined with closing-opening technique (a modified vertebral column resection) for the treatment of thoracic and thoracolumbar angular kyphosis

Abstract

Object: The purpose of this study was to determine the efficacy of a modified vertebral column resection for the treatment of thoracolumbar angular kyphosis.

Methods: A total of 13 patients (8 male, 5 female) with thoracolumbar kyphosis (kyphotic angle > 60°) were included in this study (Group A). There were 3 patients with failure of spinal formation (Type 1 deformity), 6 patients with old thoracic or lumbar compression fracture, and 4 patients with old spinal tuberculosis (including 1 case of T3-5 vertebral malunion). The average preoperative kyphotic angle was 67.3° (range 62°-75°). Each patient underwent an expanded eggshell procedure combined with the closing-opening technique for the treatment of thoracolumbar angular kyphosis. Sixteen patients who were previously treated with a closing-opening wedge osteotomy in the same spine classification group (kyphotic angle > 60°) were used as a control group (Group B).

Results: In Group A, the average (± SD) operative time was 400 ± 60 minutes, and the average blood loss was 960 ± 120 ml. There were no surgery-related complications observed during or after the operations. The average local kyphotic angle was 20.3° (range 18°-24.5°), and the average correction rate was 68.7%. In Group B, the average operative time was 470 ± 90 minutes, and the average blood loss was 2600 ± 1600 ml (range 1200-8200 ml). There were segmental vessels and spinal canal venous plexus injury in 1 case, spinal cord injury in 1 case, dural tearing in 2 cases, pleural rupture in 2 cases, and hemothorax and pneumothorax in 1 case. Each patient had more than 2 years of follow-up. At the latest follow-up examination, the average regional kyphotic angle was 19.9° ± 9.1° (range 19°-34°), and there was no significant loss of correction (p > 0.05). There was greater blood loss and a higher complication rate in Group B than in Group A (p < 0.05).

Conclusions: An expanded eggshell procedure combined with the closing-opening technique for the treatment of thoracolumbar angular kyphosis resulted in significant reduction of the kyphotic angle, few complications, and good follow-up results. However, a larger series of patients and long-term follow-up results is still required to verify the effectiveness and safety of this method.

Keywords: ASIA = American Spinal Injury Association; COWO = closing-opening wedge osteotomy; LL = lumbar lordosis; PI = pelvic incidence; PSO = pedicle subtraction osteotomy; PT = pelvic tilt; PVCR = posterior vertebral column resection; RKA = regional kyphotic angle; SPO = Smith-Petersen osteotomy; SVA = sagittal vertical axis; TK = thoracic kyphosis; VAS = visual analog scale; VCR = vertebral column resection; closing-opening procedure; correction; eggshell; kyphosis; technique; thoracic spine.