背景:跨跟骨缝合技术是修复跟腱套撕脱的一种经济有效的方法。此技术的松质骨固定是否可以加速肌腱到骨的愈合尚不清楚。这项研究的目的是通过一种新型的大鼠跨跟骨缝合模型比较皮质骨固定与松质骨固定对腱-骨愈合的影响。
方法:对雄性Sprague-Dawley大鼠(N=80)的右后肢进行跟骨缝合处理。随机分为皮质组(跟腱固定于跟骨皮质骨,n=40)和松质骨组(跟腱固定在跟骨松质骨上,n=40)。术后1、4、7和14天进行步态分析和免疫组织化学。Grossobservation,生物力学分析,Micro-CT,术后4周和8周进行组织学分析。组间比较采用独立样本t检验。
结果:在第1、4和7天,松质骨组患肢摆动时间减少,而占空比,最大接触面积,打印区,平均强度显著增加。松质骨组的腱-骨连接处的横截面面积较小,术后4周破坏载荷和刚度均较高。术后4周时,松质骨组显示出更多的新骨比例以及相对组织良好和致密的结缔组织界面,纤维软骨样组织更好。在第1、4、7和14天,松质层组的ED2+巨噬细胞比例显著高于皮质组。2周时步态无显著差异,在外观上,生物力学,新骨形成,术后8周组织学改变。
结论:在新的大鼠经跟骨缝合模型中,松质骨固定可以在早期加速腱-骨愈合,这可能与调节炎症过程的松质骨中丰富的骨髓组织有关。
BACKGROUND: Trans-calcaneal suture technique is an economical and effective method for repairing Achilles tendon sleeve avulsion. Whether cancellous bone fixation upon this technique could accelerate tendon-to-bone healing is unknown. The purpose of this study is to compare the effect of cortical versus cancellous bone fixation on tendon-bone healing with a novel rat trans-calcaneal suture model.
METHODS: Trans-calcaneal suture treatment was carried out on the right hindlimb in male Sprague-Dawley rats (N = 80). They were randomly divided into the cortical group (Achilles fixed to the calcaneal cortical bone, n = 40) and the cancellous group (Achilles fixed to the calcaneal cancellous bone, n = 40). Gait analysis and immunohistochemistry were performed 1, 4, 7, and 14 days after the operation. Gross observation, biomechanical analysis, micro-CT, and histological analysis were performed 4 and 8 weeks after surgery. Independent-samples t tests were used for comparison between groups.
RESULTS: At 1, 4, and 7 days, the swing time of the affected limb in the cancellous group decreased, while the duty cycle, the maximum contact area, the print area, and the mean intensity increased significantly. The cross-sectional area of the tendon-bone junction in the cancellous group was smaller, and the failure load and stiffness were higher 4 weeks after the operation. The cancellous group showed more proportion of new bone and a relatively well-organized and dense connective tissue interface with better fibrocartilage-like tissue at 4 weeks after the operation. The ratio of ED2 + macrophages in the cancellous group was significantly higher than in the cortical group on 1, 4, 7, and 14 days. There were no significant differences in gait at 2 weeks, in appearance, biomechanics, new bone formation, and histology at 8 weeks after surgery between the two groups.
CONCLUSIONS: In the new rat trans-calcaneal suture model, cancellous fixation can accelerate tendon-to-bone healing in the early stage, which perhaps is related to the abundant bone marrow tissue in the cancellous bone that modulates the inflammatory processes.