Lorenz Boehler Trauma Hospital, Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, Cluster for Tissue Regeneration, Vienna, Austria.
Wien Klin Wochenschr. 2011 Jan;123(1-2):4-10. doi: 10.1007/s00508-010-1488-9.
Volar fixed-angle plating is a popular treatment for unstable distal radius fractures. Despite the availability of plating systems for treating distal radius fractures, little is known about the mechanical properties of multidirectional fixed-angle plates. The aim of this study was to compare the primary fixation stability of three possible screw configurations in a distal extra-articular fracture model using a multidirectional fixed-angle plate with metaphyseal cancellous screws distally.
Eighteen Sawbones radii (Sawbones, Sweden, model# 1027) were used to simulate an extra-articular distal radius fracture according to AO/OTA 23 A3. Plates were fixed to the shaft with one non-locking screw in the oval hole and two locking screws as recommended by the manufacturer. Three groups (n = 6) were defined by screw configuration in the distal metaphyseal fragment: Group 1: distal row of screws only; Group 2: 2 rows of screws, parallel insertion; Group 3: 2 rows of screws, proximal screws inserted with 30° of inclination. Specimens underwent mechanical testing under axial compression within the elastic range and load controlled between 20 N and 200 N at a rate of 40 N/s. Axial stiffness and type of construct failure were recorded.
There was no difference regarding axial stiffness between the three groups. In every specimen, failure of the Sawbone-implant-construct occurred as plastic bending of the volar titanium plate when the dorsal wedge was closed.
Considering the limitations of the study, the recommendation to use two rows of screws or to place screws in the proximal metaphyseal row with inclination cannot be supported by our mechanical data.
掌侧固定角度接骨板是治疗不稳定桡骨远端骨折的常用方法。尽管有多种治疗桡骨远端骨折的接骨板系统，但对于多向固定角度板的力学性能知之甚少。本研究旨在比较三种可能的螺钉构型在使用带有骨干松质骨螺钉的多向固定角度板治疗桡骨远端关节外骨折模型中的初始固定稳定性。
使用 18 个 Sawbones 桡骨（Sawbones，瑞典，型号#1027）根据 AO/OTA 23 A3 模拟关节外桡骨远端骨折。按照制造商的建议，将钢板用 1 个非锁定螺钉固定在椭圆形孔中的骨干上，并用 2 个锁定螺钉固定。根据远端骨干碎片中的螺钉构型将 3 组（n=6）定义为：组 1：仅远端排螺钉；组 2：2 排螺钉，平行插入；组 3：2 排螺钉，近端螺钉以 30°的倾斜角插入。标本在弹性范围内进行轴向压缩的力学测试，并在 40 N/s 的速率下以 20 N 至 200 N 的载荷进行控制。记录轴向刚度和结构失效类型。
三组之间的轴向刚度没有差异。在每个标本中，当背侧楔形块闭合时，Sawbone-植入物-结构的失效均表现为掌侧钛板的塑性弯曲。
考虑到研究的局限性，我们的力学数据不支持使用两排螺钉或倾斜放置近端骨干排螺钉的建议。
