Ménard Anne-Laure, Grimard Guy, Londono Irène, Beaudry Francis, Vachon Pascal, Moldovan Florina, Villemure Isabelle
Dept. of Mechanical Engineering, École Polytechnique of Montreal, P.O. Box 6079, Station "Centre-Ville", Montréal, Québec H3C 3A7, Canada; Sainte-Justine University Hospital Research Center, 3175 Côte-Ste-Catherine Rd., Montréal, Québec H3T 1C5, Canada.
Sainte-Justine University Hospital Research Center, 3175 Côte-Ste-Catherine Rd., Montréal, Québec H3T 1C5, Canada; Sainte-Justine University Hospital Center, 3175 Côte-Ste-Catherine Rd., Montréal, Québec, H3T 1C5, Canada.
Bone. 2015 Dec;81:662-668. doi: 10.1016/j.bone.2015.09.013. Epub 2015 Sep 28.
Mechanical loadings influence bone growth and are used in pediatric treatments of musculoskeletal deformities. This in vivo study aimed at evaluating the effects of static and dynamic compression application and subsequent removal on bone growth, mineralization and neuropathic pain markers in growing rats. Forty-eight immature rats (28 days old) were assigned in two groups (2- and 4 weeks experiment duration) and four subgroups: control, sham, static, and dynamic. Controls had no surgery. A micro-loading device was implanted on the 6th and 8th caudal vertebrae of shams without loading, static loading at 0.2 MPa or dynamic loading at 0.2 MPa ± 30% and 0.1 Hz. In 2-week subgroups, compression was maintained for 15 days prior to euthanasia, while in 4- week subgroups, compression was removed for 10 additional days. Growth rates, histomorphometric parameters and mineralization intensity were quantified and compared. At 2 weeks, growth rates and growth plate heights of loaded groups (static/dynamic)were significantly lower than shams (p b 0.01).However, at 4 weeks, both growth rates and growth plate heights of loaded groups were similar to shams. At 4 weeks, alizarin red intensity was significantly higher in dynamics compared to shams (p b 0.05) and controls (p b 0.01). Both static and dynamic compressions enable growth resumption after loading removal, while preserving growth plate histomorphometric integrity. However, mineralization was enhanced after dynamic loading removal only. Dynamic loading showed promising results for fusionless treatment approaches for musculoskeletal deformities.
机械负荷影响骨骼生长，并用于儿童肌肉骨骼畸形的治疗。本体内研究旨在评估静态和动态压缩施加及随后去除对生长中大鼠骨骼生长、矿化和神经性疼痛标志物的影响。48只未成熟大鼠（28日龄）被分为两组（实验持续时间为2周和4周）和四个亚组：对照组、假手术组、静态组和动态组。对照组不进行手术。在假手术组的第6和第8尾椎植入微型加载装置，不进行加载、以0.2MPa进行静态加载或以0.2MPa±30%和0.1Hz进行动态加载。在2周亚组中，压缩在安乐死前提保持15天，而在4周亚组中，压缩额外去除10天。对生长速率、组织形态计量学参数和矿化强度进行量化和比较。在2周时，加载组（静态/动态）的生长速率和生长板高度显著低于假手术组（p<0.01）。然而，在4周时，加载组的生长速率和生长板高度均与假手术组相似。在4周时，与假手术组（p<0.05）和对照组（p<0.01）相比，动态组的茜素红强度显著更高。静态和动态压缩在去除加载后均能恢复生长，同时保持生长板组织形态计量学完整性。然而，仅在去除动态加载后矿化增强。动态加载对肌肉骨骼畸形的非融合治疗方法显示出有前景的结果。
