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

Abstract

PURPOSE: 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. METHODS: 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. RESULTS: 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%). CONCLUSIONS: 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.