Avery Daniel M, Klinge Stephen, Dyrna Felix, Pauzenberger Leo, Lam David, Cote Mark, DiVenere Jessica, Obopilwe Elifho, Mazzocca Augustus, Rodner Craig
UCONN Orthopaedic Sports Medicine, University of Connecticut Musculoskeletal Institute, Farmington, CT.
UCONN Orthopaedic Sports Medicine, University of Connecticut Musculoskeletal Institute, Farmington, CT.
J Hand Surg Am. 2017 May;42(5):392.e1-392.e6. doi: 10.1016/j.jhsa.2017.02.013. Epub 2017 Mar 27.
This study aimed to determine the biomechanical stability of headless compression screws in the fixation of metacarpal neck fractures and to compare them with another common, less invasive form of fixation, K-wires. The hypothesis was that headless compression screws would show higher stiffness and peak load to failure than K-wire fixation.
Eight matched-paired hands (n = 31), using the ring and little finger metacarpals, had metacarpal fractures simulated at the physeal scar. Each group was stabilized with either a 3.5-mm headless compression screw or 2 0.045-in (1.1-mm) K-wires. Nineteen metacarpals were tested in 3-point bending and 12 in axial loading. Peak load to failure and stiffness were calculated from the load displacement curve. Bone mineral density was recorded for each specimen.
Bone mineral density was similar in the 2 groups tested for 3-point bending and axial loading. Stiffness was not significantly different in 3-point bending for headless compression screws and K-wires (means, 141.3 vs 194.5 N/mm) but it was significant in axial loading (means, 178.0 vs 111.6 N/mm). Peak load to failure was significantly higher in headless compression screws in 3-point bending (means, 401.2 vs 205.3 N) and axial loading (means, 467.5 vs 198.3 N).
Compared with K-wires, headless compression screws for metacarpal neck fractures are biomechanically superior in load to failure, 3-point bending, and axial loading.
Headless compression screws demonstrate excellent biomechanical stability in metacarpal neck fractures. In conjunction with promising clinical studies, these data suggest that headless compression screws may be an option for treating metacarpal neck fractures.
本研究旨在确定无头加压螺钉固定掌骨颈骨折的生物力学稳定性，并将其与另一种常见的、侵入性较小的固定方式克氏针进行比较。假设是无头加压螺钉在刚度和失效峰值载荷方面将高于克氏针固定。
使用环指和小指掌骨，对8对匹配的手（n = 31）在骨骺瘢痕处模拟掌骨骨折。每组分别用一枚3.5毫米无头加压螺钉或两根0.045英寸（1.1毫米）克氏针进行固定。19根掌骨进行三点弯曲测试，12根进行轴向加载测试。根据载荷-位移曲线计算失效峰值载荷和刚度。记录每个标本的骨密度。
在进行三点弯曲和轴向加载测试的两组中，骨密度相似。无头加压螺钉和克氏针在三点弯曲时的刚度无显著差异（平均值分别为141.3和194.5 N/mm），但在轴向加载时差异显著（平均值分别为178.0和111.6 N/mm）。无头加压螺钉在三点弯曲（平均值分别为401.2和205.3 N）和轴向加载（平均值分别为467.5和198.3 N）时的失效峰值载荷显著更高。
与克氏针相比，用于掌骨颈骨折的无头加压螺钉在失效载荷、三点弯曲和轴向加载方面具有生物力学优势。
无头加压螺钉在掌骨颈骨折中表现出优异的生物力学稳定性。结合有前景的临床研究，这些数据表明无头加压螺钉可能是治疗掌骨颈骨折的一种选择。
