Theologis Alekos A, DePhillips Jason, Myers Nathaniel A, Mahoney Jonathan M, Bucklen Brandon S
Department of Orthopaedic Surgery, University of California - San Francisco (UCSF), 500 Parnassus Ave, MUW 3rd Floor, San Francisco, CA, 94143, USA.
Scientific Affairs, Globus Medical Inc., Audubon, PA, USA.
Spine Deform. 2025 Mar 28. doi: 10.1007/s43390-025-01079-y.
To compare screw strains adjacent to a simulated spinal osteotomy between segmental compression (SC) and cantilever bending (CB) to SC and CB performed over a construct-to-construct lateral accessory rod ("rail").
10 PCF foam blocks were instrumented with 6 polyaxial pedicle screws, each with a linear strain gage. SC and CB were performed over a traditional construct (midline rods) or over a construct-to-construct lateral accessory rod. Real-time screw strains were collected and peak strains were reported and compared between corrective techniques.
Strains in screws closest to the osteotomy were significantly less during "rail" compression compared to traditional SC. Maximum screw strains were significantly lower during "rail" SC (p < .001) and CB (p = 0.003) compared to traditional SC and CB, respectively. Total screw strain was more evenly distributed over all 6 screws during "rail" compression and CB compared to traditional techniques, which concentrated strain at individual screws adjacent to the osteotomy.
Performing SC and CB across an accessory construct-to-construct lateral ("rail") rod resulted in significantly lower strain on individual pedicle screws adjacent to a simulated spinal osteotomy compared to traditional SC and CB. As such, the "rail" may lessen risk of screw pull-out and screw plow during maneuvers to correct spinal deformities. Future work focused on building upon this controlled study in cadaveric specimens will be important to validate these findings in more clinically relevant scenarios.
比较在模拟脊柱截骨术相邻部位，节段性加压（SC）和悬臂弯曲（CB）在跨越结构间横向辅助杆（“轨道”）进行时与传统SC和CB情况下螺钉的应变情况。
10个PCF泡沫块用6枚多轴椎弓根螺钉进行器械固定，每枚螺钉带有线性应变片。SC和CB分别在传统结构（中线杆）或跨越结构间横向辅助杆的情况下进行。收集实时螺钉应变数据，报告并比较不同矫正技术下的峰值应变。
与传统SC相比，在“轨道”加压过程中，最靠近截骨术部位的螺钉应变明显更小。与传统SC和CB相比，“轨道”SC（p < 0.001）和CB（p = 0.003）过程中的最大螺钉应变分别显著更低。与传统技术相比，在“轨道”加压和CB过程中，总螺钉应变在所有6枚螺钉上分布更均匀，传统技术会使应变集中在截骨术相邻的单个螺钉上。
与传统SC和CB相比，通过辅助的结构间横向（“轨道”）杆进行SC和CB，可使模拟脊柱截骨术相邻的单个椎弓根螺钉上的应变显著降低。因此，在矫正脊柱畸形的操作过程中，“轨道”可能会降低螺钉拔出和螺钉切割的风险。未来基于此尸体标本对照研究开展的工作对于在更具临床相关性的场景中验证这些发现至关重要。
