Heinrich Heine University Hospital Düsseldorf, Department of Trauma and Hand Surgery, Moorenstr. 5, D-40225 Düsseldorf, Germany.
Injury. 2012 Aug;43(8):1290-5. doi: 10.1016/j.injury.2012.04.020. Epub 2012 May 17.
Operative treatment of patella fractures is frequently associated with implant failure and secondary dislocation which can be attributed to the employed hardware. Therefore, a 2.7 mm fixed-angle plate designed for the treatment of patella fractures was tested biomechanically against the currently preferred methods of fixation. It was hypothesized that under simulated cyclic loading fixed-angle plating would be superior to modified anterior tension wiring or cannulated lag screws with anterior tension wiring.
Eighteen human cadaver knees, matched by bone mineral density and age, were divided into three groups of six. After setting a transverse patella fracture each group received one of the osteosyntheses mentioned above. Repetitive testing over 100 cycles was performed at non-destructive loads by simulating knee motion from 90° flexion to full extension.
Anterior tension wiring as well as lag screws with tension wiring showed significant fracture displacement after the initial cycle already. Both constructs, lag screws plus wiring (3.7 ± 2.7 mm) as well as tension wiring alone (7.1 ± 2.2 mm) displayed fracture displacement of >2 mm which is clinically regarded as failure. Those patellae stabilized with fixed-angle plates showed no significant fracture gap widening after completion of 100 cycles (0.7 ± 0.5 mm). The differences between the fixed-angle plate group and the other two groups were statistically significant (p<0.05).
In contrast to modified anterior tension wiring and cannulated lag screws with anterior tension wiring the bilateral fixed-angle plate was the only fixation device to stabilize transverse patella fractures securely and sustainably.
髌骨骨折的手术治疗常伴有植入物失败和继发性脱位，这可归因于所使用的内固定物。因此，我们对一种 2.7 毫米的固定角度钢板进行了生物力学测试，该钢板是专门设计用于治疗髌骨骨折的，与目前首选的固定方法进行了对比。我们假设，在模拟循环载荷下，与改良的前侧张力线或带前侧张力线的空心拉力螺钉相比，使用固定角度钢板固定具有优势。
18 个人体冷冻膝关节标本，按骨密度和年龄匹配，分为三组，每组 6 个。在建立横断髌骨骨折后，每组分别接受上述三种内固定方式之一。通过模拟膝关节从 90°屈曲到完全伸展的运动，在无损负荷下进行 100 次以上的重复测试。
在前侧张力线和带张力线的拉力螺钉固定后，初始循环后即出现明显的骨折移位。这两种结构，带张力线的拉力螺钉（3.7±2.7mm）和单独的张力线（7.1±2.2mm）都显示出>2mm的骨折位移，这在临床上被认为是失败。用固定角度钢板固定的髌骨在完成 100 次循环后没有明显的骨折间隙增宽（0.7±0.5mm）。固定角度钢板组与其他两组之间的差异具有统计学意义（p<0.05）。
与改良的前侧张力线和带前侧张力线的空心拉力螺钉相比，双侧固定角度钢板是唯一能够稳定和持续固定横断髌骨骨折的固定装置。
