Olsson O, Kummer F J, Ceder L, Koval K J, Larsson S, Zuckerman J D
Department of Orthopedics, Helsingborg Hospital, Sweden.
Acta Orthop Scand. 1998 Jun;69(3):266-72. doi: 10.3109/17453679809000927.
The Medoff sliding plate has a dual side capability along both the femoral shaft and neck to increase theoretically interfragmentary compression and load-sharing in hip fractures. We studied intertrochanteric fracture fixation in cadaveric bone to determine whether this device has a mechanical advantage over a standard sliding hip screw. 2-part and 4-part fractures were created in 12 cadaver femurs. The fractures were fixated and sequentially destabilized; bone and plate strains and fragment displacements were determined during testing, as a function of applied physiological loads before and after short-term cycling. The Medoff sliding plate imposed a higher mean medial cortex strain than the sliding hip screw in all fracture models and at all loading levels, and the difference was statistically significant in the 2-part and in the unstable 4-part fracture models. The loading of the medial cortex region after cycling was approximately 50% higher in the Medoff samples than in the sliding hip screw samples. There were no significant differences in plate strains, fracture displacements or load to failure between the 2 devices. These observations favor the dual sliding principle as regards providing fracture compression and load-sharing, which may explain low failure rates in clinical series of unstable intertrochanteric fractures, treated with the Medoff sliding plate.
梅多夫滑动钢板在股骨干和股骨颈两侧均具有双重作用，理论上可增加髋部骨折的骨折块间压缩力和负荷分担。我们在尸体骨上研究了转子间骨折固定，以确定该装置相对于标准滑动髋螺钉是否具有机械优势。在12具尸体股骨上制造了二部分和四部分骨折。对骨折进行固定并依次使其不稳定；在测试过程中，根据短期循环前后施加的生理负荷，确定骨和钢板的应变以及骨折块位移。在所有骨折模型和所有负荷水平下，梅多夫滑动钢板产生的平均内侧皮质应变均高于滑动髋螺钉，在二部分骨折模型和不稳定的四部分骨折模型中，这种差异具有统计学意义。循环后，梅多夫样本中内侧皮质区域的负荷比滑动髋螺钉样本高约50%。两种装置在钢板应变、骨折位移或破坏负荷方面无显著差异。这些观察结果支持了双重滑动原理在提供骨折压缩和负荷分担方面的作用，这可能解释了使用梅多夫滑动钢板治疗不稳定转子间骨折的临床系列中较低的失败率。
