Board T N, Rooney P, Kay P R
The Centre for Hip Surgery Wrightington Hospital, Appley Bridge, Wigan WN6 9EP, UK.
J Bone Joint Surg Br. 2008 Jun;90(6):821-4. doi: 10.1302/0301-620X.90B6.20234.
In order to investigate the osteoinductive properties of allograft used in impaction grafting and the effect of strain during impaction on these properties, we designed an in vitro experiment to measure strain-related release of bone morphogenetic protein-7 (BMP-7) from fresh-frozen femoral head allograft. A total of 40 10 mm cubes of cancellous bone were cut from ten samples of fresh-frozen femoral head. The marrow was removed from the cubes and the baseline concentrations of BMP-7 were measured. Specimens from each femoral head were allocated to four groups and subjected to different compressive strains with a material testing machine, after which BMP-7 activity was reassessed. It was present in all groups. There was a linear increase of 102.1 pg/g (95% confidence interval 68.6 to 135.6) BMP-7 for each 10% increase in strain. At 80% strain the mean concentration of BMP-7 released (830.3 pg/g bone) was approximately four times that released at 20% strain. Activity of BMP-7 in fresh-frozen allograft has not previously been demonstrated. This study shows that the freezing and storage of femoral heads allows some maintenance of biological activity, and that impaction grafting provides a source of osteoinductive bone for remodelling. We have shown that BMP-7 is released from fresh-frozen femoral head cancellous bone in proportion to the strain applied to the bone. This suggests that the impaction process itself may contribute to the biological process of remodelling and bony incorporation.
为了研究嵌压植骨中使用的同种异体移植物的骨诱导特性以及嵌压过程中的应变对这些特性的影响，我们设计了一项体外实验，以测量新鲜冷冻股骨头同种异体移植物中与应变相关的骨形态发生蛋白-7（BMP-7）释放情况。从十个新鲜冷冻股骨头样本中切取了总共40个10毫米的松质骨立方体。将骨髓从立方体中去除并测量BMP-7的基线浓度。将每个股骨头的标本分为四组，并用材料试验机施加不同的压缩应变，之后重新评估BMP-7活性。所有组均检测到BMP-7。应变每增加10%，BMP-7就线性增加102.1 pg/g（95%置信区间68.6至135.6）。在80%应变时，释放的BMP-7平均浓度（830.3 pg/g骨）约为20%应变时释放浓度的四倍。此前尚未证明新鲜冷冻同种异体移植物中BMP-7的活性。本研究表明，股骨头的冷冻和储存能使生物活性得到一定程度的维持，并且嵌压植骨为重塑提供了骨诱导骨的来源。我们已经表明，BMP-7从新鲜冷冻的股骨头松质骨中释放的量与施加于骨的应变成比例。这表明嵌压过程本身可能有助于重塑和骨融合的生物学过程。
