Department of Orthopaedics and Orthopaedic Surgery, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany.
Calcif Tissue Int. 2010 Jan;86(1):82-9. doi: 10.1007/s00223-009-9317-8. Epub 2009 Dec 4.
Treatment of an underlying disease is often initiated after the occurrence of an osteoporotic fracture. Our aim was to investigate whether teriparatide (PTH 1-34) and strontium ranelate affect fracture healing in ovariectomized (OVX) rats when provided for the first time after the occurrence of an osteoporotic fracture. We combined the model of an OVX rat with a closed diaphyseal fracture. Sixty Sprague Dawley rats were randomly assigned to four groups. Fracture healing in OVX rats after treatment with pharmacological doses of strontium ranelate and PTH 1-34 was compared with OVX and sham-treated control groups. After 28 days, the femur was excised and scanned by micro computed tomography and the callus evaluated, after which biomechanical torsional testing was performed and torque and toughness until reaching the yield point were analyzed. Only treatment with strontium ranelate led to a significant increase in callus resistance compared to the OVX control rats, whereas both PTH 1-34 and strontium ranelate increased the bone volume/tissue volume ratio of the callus. The PTH 1-34-increased trabecular bone volume within the callus was even higher compared to sham. As for the callus tissue volume, the increase induced by strontium ranelate was significant, contrary to the changes induced by PTH. Callus in strontium ranelate-treated animals is more resistant to torsion compared with OVX control rats. To our knowledge, this is the first report of the enhancement of fracture healing by strontium ranelate. Because both treatments enhance bone and tissue volume within the callus, there may be a qualitative difference between the calluses of PTH 1-34- and strontium ranelate-treated OVX rats. The superior results obtained with strontium ranelate compared to PTH in terms of callus resistance could be the consequence of a better quality of the new bone formed within the callus.
治疗潜在疾病通常在发生骨质疏松性骨折后开始。我们的目的是研究甲状旁腺素（PTH 1-34）和雷奈酸锶是否会影响去卵巢（OVX）大鼠在发生骨质疏松性骨折后首次出现时的骨折愈合。我们将 OVX 大鼠模型与闭合性骨干骨折相结合。将 60 只 Sprague Dawley 大鼠随机分为四组。用药理剂量的雷奈酸锶和 PTH 1-34 治疗 OVX 大鼠的骨折愈合情况，并与 OVX 和假手术对照组进行比较。28 天后，取出股骨，用微计算机断层扫描扫描，评估骨痂，然后进行生物力学扭转试验，分析达到屈服点的扭矩和韧性。只有雷奈酸锶治疗组与 OVX 对照组相比，骨痂阻力显著增加，而 PTH 1-34 和雷奈酸锶均增加了骨痂的骨体积/组织体积比。与假手术相比，PTH 1-34 增加了骨痂内的小梁骨体积。至于骨痂组织体积，雷奈酸锶诱导的变化是显著的，与 PTH 诱导的变化相反。与 OVX 对照组相比，雷奈酸锶治疗组的骨痂对扭转的抵抗力更强。据我们所知，这是雷奈酸锶增强骨折愈合的首次报道。由于两种治疗方法均增加了骨痂内的骨和组织体积，因此 PTH 1-34 和雷奈酸锶治疗的 OVX 大鼠骨痂之间可能存在质量上的差异。与 PTH 相比，雷奈酸锶在骨痂阻力方面的优越结果可能是由于骨痂内形成的新骨质量更好。
