Bowers K W, Edmonds J L, Girod D A, Jayaraman G, Chua C P, Toby E B
Section of Orthopedic Surgery, Kansas University Medical Center, Kansas City 66160, USA.
J Bone Joint Surg Am. 2000 May;82(5):694-704.
Osteocutaneous radial forearm free flaps have fallen from favor due to pathological fractures of the radius. The purposes of this study were to propose a means to decrease the rate of pathological fracture by prophylactic fixation of the donor-site defect and to evaluate this technique biomechanically.
Two groups of ten matched pairs of fresh-frozen cadaveric radii were harvested. In Group 1, an eight-centimeter length of radius comprising 50 percent of the cross-sectional area of the bone was removed to simulate an osteocutaneous radial forearm donor-site defect. This defect was created in one member of each pair, with the other bone in the pair left intact. In Group 2, both members of the ten matched pairs of radii had identical defects created as previously described. However, one radius in each pair had a twelve-hole, 3.5-millimeter dynamic compression plate placed across the segmental defect. In each group, five matched pairs were tested to failure in torsion and five matched pairs were tested to failure in four-point bending.
In Group 1, the intact radius was a mean of 5.7 times stronger in torsion and 4.2 times stronger in four-point bending than the radius with the segmental resection. In Group 2, the radius that was ostectomized and fixed with a plate was a mean of 4.0 times stronger in torsion and 2.7 times stronger in four-point bending than the ostectomized radius.
Removal of an eight-centimeter segment from the radius dramatically decreased both torsion and bending strength. Application of a plate over the defect in the radius significantly restored the strength of the radius (p = 0.01).
由于桡骨病理性骨折，桡骨前臂骨皮瓣已不再受欢迎。本研究的目的是提出一种通过预防性固定供区缺损来降低病理性骨折发生率的方法，并对该技术进行生物力学评估。
采集两组十对匹配的新鲜冷冻尸体桡骨。在第1组中，切除8厘米长的桡骨，其占骨横截面积的50%，以模拟桡骨前臂骨皮瓣供区缺损。在每对中的一根骨上制造这种缺损，而另一根骨保持完整。在第2组中，十对匹配桡骨的两根骨都制造了如前所述的相同缺损。然而，每对中的一根桡骨在节段性缺损处放置一块12孔、3.5毫米的动力加压钢板。在每组中，五对匹配的桡骨进行扭转试验直至破坏，五对匹配的桡骨进行四点弯曲试验直至破坏。
在第1组中，完整桡骨的扭转强度平均比有节段切除的桡骨强5.7倍，四点弯曲强度强4.2倍。在第2组中，切除并钢板固定的桡骨的扭转强度平均比切除的桡骨强4.0倍，四点弯曲强度强2.7倍。
从桡骨切除8厘米节段显著降低了扭转和弯曲强度。在桡骨缺损处应用钢板可显著恢复桡骨强度（p = 0.01）。
