추간체 유합술용 파일럿홀 형성 시 삽입 저항 측정 토크 드라이버 개발

초록

The fixation stability of pedicle screws is a key factor for successful outcomes in spinal arthrodesis. However, the T-score obtained from dual-energy X-ray absorptiometry does not adequately reflect the local bone quality of individual vertebral bodies. In this study, a torsion bar mechanism–based manual torque driver was developed to quantitatively measure the insertion resistance generated during the pilot hole formation process. The torsion bar material (stainless steel, titanium alloy, and nitinol) and length (70, 80, and 90 mm) were selected as design variables, and the torque response characteristics with respect to the rotation angle were analyzed through finite element analysis. The results showed that the 80 mm nitinol torsion bar exhibited excellent linear response characteristics, producing approximately 5 N·m of torque at a rotation angle of 90°. Based on these findings, a prototype torque driver was fabricated, and static and dynamic validation experiments were conducted using a torque measurement system. The measured torque values deviated by less than 2% from the FEA predictions, and stable elastic recovery was maintained under repeated torsional loading. The torque driver proposed in this study provides a practical means for quantitatively assessing insertion resistance during pilot hole formation and is expected to facilitate vertebral bone quality evaluation and optimal pedicle screw selection in clinical applications.

키워드