Evaluation of a novel angular kyphosis reduction device for vertebral column resection in severe angular kyphosis

This study aimed to introduce a novel angular kyphosis reduction device (AKRD) designed for vertebral column resection (VCR) in severe angular kyphosis and to evaluate its effectiveness and feasibility using a sawbones model and a porcine cadaver model.

A thoracolumbar angular kyphosis deformity (apex at T11) was created in a sawbones spine model and corrected using the AKRD to assess mechanical performance. Subsequently, a five-month-old porcine cadaver model was used to simulate thoracolumbar angular kyphosis, followed by deformity correction with the AKRD to evaluate its feasibility during VCR.

In the sawbones model, kyphosis was corrected from 51.9° ± 0.7° to 17.6° ± 0.8° (66.1% correction), with a 53.3% reduction in posterior elements (34.7 to 16.2 mm), 76.9% elongation of the anterior column (21.6 to 38.2 mm), and a mean apical vertebral translation of 65.9 ± 7.1 mm. In the porcine cadaver model, the AKRD maintained segmental stability during resection and achieved a 91% correction, with minimal spinal cord length change (10.8%).

The AKRD provides controlled and effective deformity correction through a cage-hinge mechanism while maintaining construct stability. These findings demonstrate its mechanical feasibility and support its potential application in VCR for severe angular kyphosis, warranting further preclinical and clinical evaluation.