Capo John T, Svach David, Ahsgar John, Orillaza Nathaniel S, Sabatino Christopher T
Division of Hand and Microvascular Surgery, UMDNJ-New Jersey Medical School, 90 Bergen St, DOC 1200, Newark, NJ 07103, USA.
Orthopedics. 2008 Oct;31(10).
Radial head and neck fractures are common and at times require operative fixation. There is no consensus on the ideal fixation construct for unstable radial neck fractures. Using 7 fresh frozen cadaveric radii, fractures of the radial neck were created 2 cm from the articular surface. The fractures were stabilized with 5 different commonly used constructs: crossed K-wires; a 2.4-mm T-plate using screws in the head (T-plate and nonlocked screw construct); a T-plate using a screw and locked buttress pin in the head (T-plate and locked buttress pin construct); a T-plate with an interfragmentary screw from the shaft retrograde, through the plate into the head (retrograde interfragmentary screw construct); and a T-plate with an interfragmentary screw from a nonarticular portion of the head antegrade into the shaft (antegrade interfragmentary screw construct). All constructs were tested for bending and torsional rigidity using an Instron mechanical testing machine (Model 306; MTS Systems, Eden Prairie, Minnesota). The highest rigidity in both bending and torsion was the antegrade interfragmentary screw construct. During bending, the antegrade interfragmentary screw construct was significantly stronger than a T-plate and nonlocked screw construct. In torsion, the retrograde interfragmentary screw construct was significantly stiffer than K-wires and approached significance over a T-plate and locked buttress pin construct. Locking bolts vs screws into the head did not significantly increase rigidity in torsion or bending. In this model, plating showed an increase in stiffness in torsional loading as compared to K-wires. The addition of a lag screw across the neck fracture consistently showed an increase in torsional and bending stiffness of the constructs. These data may assist orthopedic surgeons in determining the best fixation for radial neck fractures.
桡骨头和颈部骨折很常见，有时需要手术固定。对于不稳定的桡骨颈部骨折，理想的固定结构尚无共识。使用7根新鲜冷冻的尸体桡骨，在距关节面2厘米处制造桡骨颈部骨折。骨折用5种不同的常用结构进行固定：交叉克氏针；头部使用螺钉的2.4毫米T形钢板（T形钢板和非锁定螺钉结构）；头部使用螺钉和锁定支撑销的T形钢板（T形钢板和锁定支撑销结构）；从骨干逆行穿过钢板进入头部的带骨折间螺钉的T形钢板（逆行骨折间螺钉结构）；以及从头部非关节部分顺行进入骨干的带骨折间螺钉的T形钢板（顺行骨折间螺钉结构）。使用Instron机械测试机（型号306；MTS系统公司，明尼苏达州伊甸草原）对所有结构进行弯曲和扭转刚度测试。顺行骨折间螺钉结构在弯曲和扭转方面的刚度最高。在弯曲过程中，顺行骨折间螺钉结构明显比T形钢板和非锁定螺钉结构更强。在扭转时，逆行骨折间螺钉结构明显比克氏针更硬，并且比T形钢板和锁定支撑销结构更接近显著差异。将锁定螺栓与螺钉置入头部在扭转或弯曲时并未显著增加刚度。在该模型中，与克氏针相比，钢板在扭转加载时刚度增加。在颈部骨折处添加拉力螺钉始终显示结构的扭转和弯曲刚度增加。这些数据可能有助于骨科医生确定桡骨颈部骨折的最佳固定方法。
