Hopper S A, Schneider R K, Ratzlaff M H, White K K, Johnson C H
Department of Veterinary Clinical Sciences, Washington State University, Pullman 99164, USA.
Am J Vet Res. 1998 Feb;59(2):201-4.
To determine the effect of pin hole size and number on the breaking strength of the adult equine radius when loaded in torsion to failure.
54 pairs of equine radii from adult horses.
For test one, 12 pairs of radii were used to determine the effect of pin hole size on torsional breaking strength. A 6.35-mm hole was drilled in 1 radius, and a 9.5-mm hole was drilled in the contralateral radius. For test two, 36 pairs of radii were randomly assigned to 1 of 3 treatment groups (n = 12) to determine the effect of pin hole number on the torsional breaking strength of the equine radius. One radius of each pair served as a control, and one, three, or six 6.35-mm transcortical holes were drilled in the contralateral radius. For test three, 6 pairs of radii had torsional forces applied directly to the transfixation pins, as opposed to the bone itself. One radius of a pair served as a control, and three 6.35-mm smooth Steinman pins were placed in the contralateral radius. All radii were loaded in torsion to failure, and the breaking strengths were recorded.
Compared with the 6.35-mm hole, the 9.5-mm hole significantly decreased torsional strength of the radius. There was no significant difference in mean torsional strength between the control radii and the radii with 1, 3, or 6 transcortical holes or when the transfixation pins were loaded.
Use of up to three 6.35-mm transfixation pins can be used in a full-limb transfixation pin cast to optimize stiffness without a significant decrease (12%) in bone strength.
确定针孔大小和数量对成年马桡骨在扭转至失效时的断裂强度的影响。
来自成年马的54对马桡骨。
对于试验一，使用12对桡骨来确定针孔大小对扭转断裂强度的影响。在一根桡骨上钻一个6.35毫米的孔，在对侧桡骨上钻一个9.5毫米的孔。对于试验二，将36对桡骨随机分配到3个治疗组中的1组（n = 12），以确定针孔数量对马桡骨扭转断裂强度的影响。每对中的一根桡骨作为对照，在对侧桡骨上钻一个、三个或六个6.35毫米的穿皮质孔。对于试验三，6对桡骨的扭转力直接施加于固定针，而不是骨头本身。一对中的一根桡骨作为对照，在对侧桡骨中放置三根6.35毫米的光滑斯氏针。所有桡骨均进行扭转加载直至失效，并记录断裂强度。
与6.35毫米的孔相比，9.5毫米的孔显著降低了桡骨的扭转强度。对照桡骨与有1个、3个或6个穿皮质孔的桡骨之间，或固定针加载时的平均扭转强度没有显著差异。
在全肢固定针石膏中使用多达三根6.35毫米的固定针可优化刚度，而不会使骨强度显著降低（12%）。
