Goodship A E, Walker P C, McNally D, Chambers T, Green J R
Department of Anatomy, University of Bristol, U.K.
Ann Oncol. 1994;5 Suppl 7:S53-5.
Bisphosphonates influence the morphology and mechanical properties of bones in growing rats, but their effects on fracture repair are not well documented. This study tests the hypothesis that bisphosphonates will modulate the remodelling phase of fracture repair, influencing the mechanical properties of healing bone. The effects of a bisphosphonate (pamidronate, Aredia) on the healing of a 3 mm osteotomy gap in the mid-diaphysis of the tibia, under rigid unilateral external fixation, were evaluated using 2 groups of 6 skeletally mature sheep. The repair process was evaluated weekly for 12 weeks using conventional radiographs, dual photon absorptiometry, and fracture stiffness measurements. The animals were then killed and the torsional stiffness and strength of the tibiae measured. More prolific callus formation, with an associated rise in the rate of bone mineral content, was observed in the treated group. There were no differences in in vivo fracture stiffness or postmortem torsional stiffness between the 2 groups, but torsional strength was greater in the treated group. Callus remodelling was reduced but not arrested in the treated group. Bisphosphonates act to reduce callus remodelling, leading to an increased amount of bridging callus and therefore strength. This study indicates that pamidronate has no adverse effects on the restoration of the mechanical integrity of a long bone after fracture.
双膦酸盐会影响生长中大鼠骨骼的形态和力学性能，但其对骨折修复的影响尚无充分文献记载。本研究检验了双膦酸盐会调节骨折修复的重塑阶段，影响愈合骨骼力学性能的假说。使用两组各6只骨骼成熟的绵羊，评估了一种双膦酸盐（帕米膦酸盐，阿可达）对在单侧刚性外固定下胫骨骨干中部3毫米截骨间隙愈合的影响。使用传统X线片、双能光子吸收法和骨折刚度测量，对修复过程进行了为期12周的每周评估。然后处死动物，测量胫骨的扭转刚度和强度。在治疗组中观察到更大量的骨痂形成，同时骨矿物质含量的增加。两组之间的体内骨折刚度或死后扭转刚度没有差异，但治疗组的扭转强度更大。治疗组的骨痂重塑减少但未停止。双膦酸盐的作用是减少骨痂重塑，导致桥接骨痂量增加，从而增强强度。本研究表明，帕米膦酸盐对骨折后长骨力学完整性的恢复没有不良影响。
