3D-Printed Laminae for Kyphosis in Ankylosing Spondylitis During Pedicle Subtraction Osteotomy.

OBJECTIVE

Ankylosing spondylitis (AS) often presents with spinal kyphosis, and pedicle subtraction osteotomy (PSO) is a common surgical technique for correcting AS-related kyphosis. However, after PSO, the posterior column lacks rigid bone support, potentially leading to intervertebral disc mobility and loss of correction. This study aims to introduce a novel 3D-printed laminae for the treatment of AS-related kyphosis.

METHODS

This is a retrospective cohort study. A total of 48 patients receiving posterior correction surgeries between December 2021 and January 2022 were included and divided into two groups according to whether they accepted the 3D-printed laminae. We propose a novel approach using 3D-printed laminae to enhance posterior column stability and reduce deformity loss. Sixteen patients receiving 3D-printed laminae and 32 patients who did not receive that device. We collected preoperative and postoperative radiographic parameters, perioperative data, and patient-reported clinical scores. Statistical analysis involved independent sample t tests or randomization tests for continuous variables and chi-square tests for categorical variables.

RESULTS

In the implanted group, kyphosis was corrected from 75.88° preoperatively to 27.06° postoperatively, and in the unimplanted group, from 70.98° to 28.42°. At the last follow-up, the ΔGK (global kyphosis) was 1.76° in the implanted group and 2.50° in the unimplanted group. PJA was 9.77° in the implanted group and 15.45° in the unimplanted group, showing significant differences. Two patients in the unimplanted group experienced sagittal reconstruction failure. Health-related quality of life (HRQoL) scores improved in the implanted group, with back pain scores of 2.63 and Oswestry Disability Index (ODI) scores of 13.50.

CONCLUSIONS

Our study introduces a novel 3D-printed laminae technique for AS-related kyphosis, aiding in maintaining sagittal balance. Patients reported improved subjective outcomes, including reduced pain and better HRQoL.