Read Emma K, Chandler Diane, Wilson David G
Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
Vet Surg. 2005 Mar-Apr;34(2):142-7. doi: 10.1111/j.1532-950X.2005.00022.x.
To compare the biomechanical characteristics and mode of failure of 2 techniques using parallel 5.5 mm screws for pastern joint arthrodesis in horses.
Randomized block design, for horse (1-5), method of fixation (two 5.5 mm screws versus three 5.5 mm screws), side (right, left), and end (front, hind). Constructs were tested to failure in 3-point bending.
Twenty limbs (5 cadavers).
A combined aiming device was used to facilitate screw placement. Two parallel 5.5 mm screws were inserted in lag fashion in 1 limb of a pair, and three 5.5 mm screws were inserted in the contralateral limb. Constructs were then tested in 3-point bending in a dorsal-to-palmar (plantar) direction using a materials testing machine at a loading rate of 19 mm/s. Maximal bending moment at failure and stiffness were obtained from bending moment-angular deformation curves.
There was no significant difference between two and three 5.5 mm screw constructs for bending moment and stiffness (P<.05). All constructs ultimately failed by bone fracture or screw bending. For proximal interphalangeal (PIP) joint arthrodesis constructs loaded in 3-point bending, no significant effect of treatment, side, or end on maximal bending moment or stiffness was detected.
Two 5.5 mm cortical screws inserted in parallel should provide a surgically simpler and equally strong PIP joint arthrodesis compared with three 5.5 mm cortical screws.
Two 5.5 mm cortical screws inserted in parallel for PIP joint arthrodesis should perform similarly under conditions used in this study, as three 5.5 mm screws inserted in a similar manner, when loaded under bending.
比较两种使用平行5.5毫米螺钉进行马跗关节融合术的生物力学特性及失效模式。
随机区组设计,涉及马(1 - 5匹)、固定方法(两枚5.5毫米螺钉与三枚5.5毫米螺钉)、侧别(右侧、左侧)和端部(前部、后部)。构建物在三点弯曲试验中测试至失效。
20个肢体(5具尸体)。
使用组合瞄准装置便于螺钉置入。在一对肢体中的一个肢体以拉力方式插入两枚平行的5.5毫米螺钉,在对侧肢体插入三枚5.5毫米螺钉。然后使用材料试验机以19毫米/秒的加载速率在背侧至掌侧(跖侧)方向对构建物进行三点弯曲试验。从弯矩 - 角变形曲线获得失效时的最大弯矩和刚度。
两枚和三枚5.5毫米螺钉构建物在弯矩和刚度方面无显著差异(P <.05)。所有构建物最终均因骨折或螺钉弯曲而失效。对于在三点弯曲中加载的近端指间(PIP)关节融合术构建物,未检测到治疗、侧别或端部对最大弯矩或刚度有显著影响。
与三枚5.5毫米皮质螺钉相比,平行插入两枚5.5毫米皮质螺钉应能提供手术操作更简单且强度相当的PIP关节融合术。
在本研究使用的条件下,当在弯曲载荷下时,平行插入两枚5.5毫米皮质螺钉进行PIP关节融合术的性能应与以类似方式插入三枚5.5毫米螺钉的情况相似。