Çanakkale Onsekiz Mart Üniversitesi Tıp Fakültesi Ortopedi ve Travmatoloji Anabilim Dalı, 17100 Çanakkale, Türkiye.
Jt Dis Relat Surg. 2021;32(1):51-58. doi: 10.5606/ehc.2021.75817. Epub 2021 Jan 6.
This study aims to mechanically compare five different extra-focal bi-cortical pin configurations (using two and three pins) employed for fixation of a simulated unstable extra-articular distal radius fracture with dorsal comminution using a sawbone model.
This in vitro mechanical study was conducted between June 2019 and July 2019. A standard fracture model (Arbeitsgemeinschaft für Osteosynthesefragen [AO] type 23-A3.3) was created using a fourth generation composite artificial radius bone. Five groups with two- and three-pin configurations were tested under axial, volar, and dorsal loading with a universal test device. Mean stiffness values were compared statistically.
Comparison of stiffness values from axial and volar loading tests between groups in paired comparison showed no statistically significant difference (p=0.194 and p=0.086, respectively). Dorsal loading tests showed statistically significant difference between the groups in pairwise comparison (p=0.002). Three-pin groups (Groups 3, 4, and 5) had higher stiffness values compared to two-pin groups (Groups 1 and 2) in dorsal loading tests (p=0.001). Three-pin configuration test groups with two divergent or convergent pins from the radial styloid performed better compared to both two-pin groups (p=0.01, p=0.002) in dorsal loading tests.
Our data demonstrated that the three-pin configuration with two divergent or convergent Kirschner wires from the styloid and a third wire from the dorsal/ulnar cortex had higher stiffness values compared to two-pin configurations in dorsal loading tests. When indicated, we suggest the use of a three-pin construct. Particularly in cases with a risk of volar angulation, we recommend a three-pin configuration with two divergent or convergent bi-cortical Kirschner wires.
本研究旨在通过使用骨模型，对模拟伴有背侧粉碎的不稳定关节外桡骨远端骨折的五种不同的焦点外双皮质克氏针固定（使用两针和三针）进行机械比较。
本体外力学研究于 2019 年 6 月至 7 月进行。使用第四代复合材料人工桡骨骨创建标准骨折模型（ Arbeitsgemeinschaft für Osteosynthesefragen [AO] 23-A3.3 型）。使用万能试验机对两种和三种针配置的五组进行轴向、掌侧和背侧加载测试。比较平均刚度值的统计学差异。
组间配对比较的轴向和掌侧加载试验中刚度值的比较显示无统计学显著差异（分别为 p=0.194 和 p=0.086）。背侧加载试验中组间比较有统计学显著差异（p=0.002）。与两针组（组 1 和组 2）相比，三针组（组 3、4 和组 5）在背侧加载试验中的刚度值更高（p=0.001）。与两针组相比，从桡骨茎突处发散或汇聚的两针或三针的三针构型测试组在背侧加载试验中的表现更好（p=0.01，p=0.002）。
我们的数据表明，与两针构型相比，从茎突处发散或汇聚的两针或三针的三针构型与第三根从背侧/尺侧皮质的克氏针在背侧加载试验中有更高的刚度值。在有掌侧成角风险的情况下，我们建议使用三针固定。特别是在有掌侧成角风险的情况下，我们建议使用两针或三针的发散或汇聚双皮质克氏针。
