踝关节融合交叉螺钉与前板固定的初始稳定性和刚度。

Primary stability and stiffness in ankle arthrodes-crossed screws versus anterior plating.

机构信息

Department of Orthopedics, Balgrist University Hospital, Forchstrasse 340, 8008 Zurich, Switzerland.

出版信息

Foot Ankle Surg. 2013 Sep;19(3):168-72. doi: 10.1016/j.fas.2013.04.006. Epub 2013 May 21.

DOI:10.1016/j.fas.2013.04.006

PMID:23830164

Abstract

BACKGROUND

Ankle arthrodesis is commonly used for the treatment of osteoarthritis or failed arthroplasty. Screw fixation is the predominant technique to perform ankle arthrodesis. Due to a considerable frequency of failures research suggests the use of an anatomically shaped anterior double plate system as a reliable method for isolated tibiotalar arthrodesis. The purpose of the present biomechanical study was to compare two groups of ankle fusion constructs - three screw fixation and an anterior double plate system - in terms of primary stability and stiffness.

METHODS

Six matched-pairs human cadaveric lower legs (Thiel fixated) were used in this study. One specimen from each pair was randomly assigned to be stabilized with the anterior double plate system and the other with the three-screw technique. The different arthrodesis methods were tested by dorsiflexing the foot until failure of the system, defined as rotation of the talus relative to the tibia in the sagittal plane. Experiments were performed on a universal materials testing machine. The force required to make arthrodesis fail was documented. For calculation of the stiffness, a linear regression was fitted to the force-displacement curve in the linear portion of the curve and its slope taken as the stiffness.

RESULTS

For the anatomically shaped double-plate system a mean load of 967N was needed (range from 570N to 1400N) to make arthrodesis fail. The three-screw fixation method resisted a mean load of 190N (range from 100N to 280N) (p=0.005). In terms of stiffness a mean of 56N/mm (range from 35N/mm to 79N/mm) was achieved for the anatomically shaped double-plate system whereas a mean of 10N/mm (range from 6N/mm to 18N/mm) was achieved for the three-screw fixation method (p=0.004).

CONCLUSIONS

Our biomechanical data demonstrates that the anterior double-plate system is significantly superior to the three-screw fixation technique for ankle arthrodesis in terms of primary stability and stiffness.

摘要

背景

踝关节融合术常用于治疗骨关节炎或人工关节置换失败。螺钉固定是进行踝关节融合术的主要技术。由于失败率相当高，研究表明使用解剖形状的前双板系统作为单独距骨-胫骨融合术的可靠方法。本生物力学研究的目的是比较两种踝关节融合构建 - 三螺钉固定和前双板系统 - 在初始稳定性和刚度方面。

方法

本研究使用了 6 对配对的人尸体小腿（Thiel 固定）。每对标本中的一个随机分配用前双板系统和另一个用三螺钉技术固定。通过背屈脚直到系统失效来测试不同的融合方法，定义为距骨相对于胫骨在矢状面的旋转。实验在万能材料试验机上进行。记录使融合失效所需的力。为了计算刚度，在线性部分拟合力 - 位移曲线，并取其斜率作为刚度。

结果

对于解剖形状的双板系统，使融合失效需要平均 967N 的力（范围为 570N 至 1400N）。三螺钉固定方法抵抗平均 190N 的力（范围为 100N 至 280N）（p=0.005）。在刚度方面，解剖形状的双板系统的平均为 56N/mm（范围为 35N/mm 至 79N/mm），而三螺钉固定方法的平均为 10N/mm（范围为 6N/mm 至 18N/mm）（p=0.004）。