Wolf Jonathon C, Weil Wayne M, Hanel Douglas P, Trumble Thomas E
University of Washington Hand Center, Harborview Medical Center, Department of Orthopaedics and Sports Medicine, University of Washington, Seattle, WA, USA.
J Hand Surg Am. 2006 Dec;31(10):1578-86. doi: 10.1016/j.jhsa.2006.09.014.
To compare the biomechanic stability of distal radius fracture fixation with a new internal radiocarpal-spanning 2.4-mm locking plate, which acts as an internal distal radius fixator, versus a standard distal radius external fixator. The number of locking screws necessary for adequate fracture fixation was also assessed.
Ten cadaveric specimens were mounted in a loading fixture with cables attached to the 2 flexor and 3 extensor wrist tendons. A 1-cm osteotomy was created to simulate an unstable distal radius fracture. The radiocarpal-spanning locking plate was fixed to the radius and index metacarpal with 4 screws proximally and 4 distally. The specimen was incrementally loaded through the tendons. Motion at the fracture site was determined. Screws were sequentially removed from the construct, the specimen was again incrementally loaded, and fracture motion was measured. The fixation was then changed to an external fixator, and the loading tests were repeated.
Fracture fixation with the radiocarpal-spanning 2.4-mm locking plate was significantly more stable with 4 screws proximally and 4 screws distally (4 x 4) and with the 3 x 3 configuration than with the external fixator in both flexion and extension. The 4 x 4 screw configuration was not significantly different from the 3 x 3 screw configuration. The 4 x 4 screw configuration was significantly more stable than the 2 x 2 and 1 x 1 screw configurations in both flexion and extension. All internal fixator configurations and the external fixator showed more fracture displacement at increasingly higher loads.
Fracture fixation with the new internal radiocarpal-spanning 2.4-mm locking plate is more stable than with a standard distal radius external fixator. Only three 2.4-mm locking screws proximally and three 2.4-mm locking screws distally are required for adequate fixation of the locking spanning plate.
比较使用新型跨腕关节的2.4毫米锁定钢板（作为桡骨远端内固定器）与标准桡骨远端外固定器治疗桡骨远端骨折的生物力学稳定性。同时评估骨折充分固定所需的锁定螺钉数量。
将10具尸体标本安装在加载装置上，通过缆线连接到2条屈腕肌腱和3条伸腕肌腱。制造1厘米的截骨术以模拟不稳定的桡骨远端骨折。将跨腕关节锁定钢板通过近端4枚螺钉和远端4枚螺钉固定于桡骨和第二掌骨。通过肌腱对标本进行递增加载。测定骨折部位的活动度。从固定结构中依次取出螺钉，再次对标本进行递增加载，并测量骨折活动度。然后将固定方式改为外固定器，并重复加载试验。
在屈曲和伸展时，使用近端4枚螺钉和远端4枚螺钉（4×4）以及使用3×3配置的跨腕关节2.4毫米锁定钢板进行骨折固定，均比外固定器显著更稳定。4×4螺钉配置与3×3螺钉配置无显著差异。在屈曲和伸展时，4×4螺钉配置均比2×2和1×1螺钉配置显著更稳定。在负荷逐渐增加时，所有内固定器配置和外固定器均显示出更多的骨折移位。
新型跨腕关节2.4毫米锁定钢板进行骨折固定比标准桡骨远端外固定器更稳定。锁定跨关节钢板充分固定仅需近端3枚2.4毫米锁定螺钉和远端3枚2.4毫米锁定螺钉。
