Horne Landon T, Murray Peter M, Saha Subrata, Sidhar Kathryn
Kaiser Permanante, Portland, OR, USA.
J Hand Surg Am. 2010 Feb;35(2):262-6. doi: 10.1016/j.jhsa.2009.10.034.
The effect of metaphyseal cancellous bone graft harvest on distal radius compressive strength is unknown. The purpose of this study was to analyze, in a cadaveric model, changes in distal radius axial compressive strength after distal radius metaphyseal cancellous bone graft harvest.
We randomized 15 matched pairs of cadaveric radiuses into 2 groups. In group I, a target harvest of 25% of the total metaphyseal cancellous bone volume was attempted through a standardized oval cortical window. In group II, a target of 50% harvest was attempted. The study specimens and their matched controls from the contralateral side were loaded to failure in axial compression. The amount of bone graft harvested was calculated. The resulting ultimate loads to failure were measured, then expressed as ultimate stress (millipascals--MPa). We analyzed data for the 2 groups and the matched controls using paired Student's t-tests.
A smaller amount of bone was harvested than anticipated in both groups. The final average distal radius bone graft harvest for group I was 10%, and for group II, 22.5%. Group I had no statistically significant difference in ultimate stress compared with the contralateral specimens that acted as matched controls (p = .273). Group II had a statistically significant decrease in ultimate stress values compared with matched controls (p = .002). The ultimate stress of group I averaged 92.67% of its matched control, whereas the ultimate stress of group II was 74.8% of its matched control (p = .027).
A significant decrease in distal radius ultimate stress occurs when approximately 23% of the metaphyseal cancellous bone is removed through a standardized oval cortical window. When the distal radius is chosen as the bone graft harvest site, we recommend harvest of less than 25% of the total available distal radius metaphyseal cancellous bone to prevent alteration of the load characteristics of the bone.
干骺端松质骨移植取材对桡骨远端抗压强度的影响尚不清楚。本研究的目的是在尸体模型中分析桡骨干骺端松质骨移植取材后桡骨远端轴向抗压强度的变化。
我们将15对匹配的尸体桡骨随机分为2组。在第一组中，试图通过标准化的椭圆形皮质骨窗获取占干骺端松质骨总体积25%的目标取材量。在第二组中，试图获取50%的取材目标量。将研究标本及其对侧的匹配对照进行轴向压缩直至破坏。计算获取的骨移植材料量。测量产生的最终破坏载荷，然后表示为极限应力（兆帕——MPa）。我们使用配对学生t检验分析两组数据以及匹配对照的数据。
两组获取的骨量均少于预期。第一组最终平均桡骨远端骨移植取材量为10%，第二组为22.5%。与作为匹配对照的对侧标本相比，第一组在极限应力方面无统计学显著差异（p = 0.273）。与匹配对照相比，第二组的极限应力值有统计学显著降低（p = 0.002）。第一组的极限应力平均为其匹配对照的92.67%，而第二组的极限应力为其匹配对照的74.8%（p = 0.027）。
当通过标准化的椭圆形皮质骨窗去除约23%的干骺端松质骨时，桡骨远端极限应力会显著降低。当选择桡骨远端作为骨移植取材部位时，我们建议取材量少于桡骨远端干骺端可用松质骨总量的25%，以防止骨的载荷特性发生改变。
