肌腱力学生物学与运动性肌腱损伤病理机制研究进展

肌腱是一种机械敏感组织,通过细胞通路和高度特化的细胞外基质之间复杂的相互作用,对不同大小、方向、频率和持续时间的机械负荷作出反应。力学生物学信号是肌腱发育、成熟、退行性变和损伤后修复的关键因素。异常负荷导致肌腱损伤,但其机制尚不清楚。了解肌腱发育、稳态和修复过程中涉及的力学生物学知识对于运动性肌腱损伤的病理机制研究、肌腱损伤的预防和治疗至关重要。本文归纳了肌腱的力学生物学研究进展,指出机械负荷与肌腱发育、稳态维持、损伤修复和退行性改变的关系,概述了肌腱细胞和肌腱干细胞对力学信号的反应,在此基础上,对运动性肌腱损伤的病理机制进行探讨,为肌腱损伤的治疗提供科学基础。     

生长因子基因治疗与干细胞治疗在肌腱损伤愈合中的应用进展

<正>由于全民健身运动的普及,运动、外伤等因素造成的肌腱损伤越来越多,严重影响人们的生活质量并且带来沉重的经济负担。肌腱愈合的潜力有限以及目前外科治疗手段不完善,促使加快发展可替代的治疗方式以促进肌腱组织再生。近些年来提出的组织工程肌腱为肌腱损伤修复提供了可行的途径,即通过联合支架材料、种子细胞、生长因子形成组织工程肌腱以促进肌腱再生~[1]。然而生长因子存在价格昂贵、半衰期短、生物活性较低、所需剂量高且难以控制、直接注射可能     

韧带和肌腱修复的基因治疗进展

韧带和肌腱是平行纤维带，由致密结缔组织构成，对保持关节正常运动和稳定性起重要作用。这些结构损伤可导致明显关节不稳，引起其他组织损伤并发展成退行性关节疾病。韧带和肌腱愈合是一个很复杂的过程。在愈合阶段，纤维母细胞和其他类型细胞受生长因子影响表现出特殊生物学行为。近来研究表明，转基因技术提供了新的改善韧带和肌腱愈合的方法。     

屈指肌腱损伤修复术后早期活动作用的实验研究

选用白来亨鸡56只,建立肌腱损伤的模型并设计不同的术后活动方法及制动方法。为比较这些方法对损伤肌腱愈合及功能的影响,进行了实体显微镜、普通光学显微镜、扫描电镜等项观察,并测量了肌腱的滑动功能。结果表明:适量的术后早期活动可促进损伤肌腱的愈合,改善其滑动功能,而制动则不利于肌腱损伤的修复及功能的恢复。     

TGF-β1多效性与肌腱修复研究进展

肌腱修复历来困扰着腱病患者,转化生长因子β1(transforming growth factor-β1,TGF-β1)作为参与肌腱修复的重要因子,它在修复过程中的多种生物学效应备受关注。本文就肌腱修复过程中TGF-β1的表达,TGF-β1在肌腱修复中的多效性及其参与肌腱修复途径的研究现状进行综述,以期为最终了解肌腱修复机制提供参考和依据。     

基因治疗韧带肌腱损伤进展

韧带肌腱损伤后多数经过手术能够治愈,但愈合后的组织几乎不能恢复其正常特征,而且在损伤的修复过程中会有瘢痕组织和黏连形成,与韧带肌腱周围所形成的黏连会影响关节的运动功能。基因治疗为韧带肌腱的修复提供了一种新手段。笔者对基因治疗的原理、可行性、研究进展、优点及面临的挑战进行概述。     

干细胞促进肌腱损伤修复研究进展

肌腱损伤在体育运动及其他剧烈活动中均十分常见,肌腱损伤后往往愈合不理想,必然影响患者的运动功能.肌腱自身再生能力较差,自然愈合常形成瘢痕组织,导致机械性能下降,且容易再次损伤.肌腱损伤的常规治疗方法包括非手术治疗及手术治疗,但这些治疗方法均疗效有限,不能恢复肌腱的自然结构及机械性能.目前仍没有理想、有效的治疗方法,临床迫切需要确实有效的治疗方案.干细胞治疗可维持肌腱的自我平衡、促进损伤肌腱组织再生,是一项极有前景的治疗手段.但目前尚无干细胞治疗肌腱损伤的最佳方案.     

预防肌腱粘连的研究进展

肌腱手术后粘连仍是难题之一。随着肌腱愈合理论的不断发展，对肌腱粘连预防的研究也在不断深入，现就这方面的研究进展综述如下。肌腱粘连与肌腱愈合的关系肌腱愈合过程中是否一定会形成粘连，一直存在着争议。持外源性愈合观点者认为，肌腱愈合过程是腱周组织来源的粘连带入血运和修复细胞来完成的，粘连不可避免。持内源性愈合观点者则认为，肌腱细胞本身具有修复损伤的能力，肌腱愈合并不是必须靠腱周组织增生来完成，粘连是可以避免的。最近的研究表明，肌腱愈合过程中内、外源愈合是同时存在的，哪种方式占主导地位，取决于肌腱内外的…     

不同来源间充质干细胞构建组织工程肌腱的可行性评估

骨关节外科患者肌腱损伤非常普遍,传统治疗不仅愈合时间长,且常发生并发症.采用组织工程技术构建组织工程肌腱为治疗肌腱损伤带来了新的希望,提供了一种新的治疗策略.既往已报道利用间充质干细胞进行组织修复,因此,利用间充质干细胞构建组织工程肌腱修复受损肌腱可能是一个行之有效的办法.本文主要综述了利用常见来源间充质干细胞构建组织工程肌腱的研究现状,并评估临床应用的可行性.     

肌腱修复术后肌腱粘连防治的研究现状

近年来肌腱修复术后肌腱粘连的防治方法取得了一系列进展。随着人们对肌腱修复愈合理论认识的深入,预防肌腱粘连的药物也从用单一的药物发展到药物与屏障材料结合的复合式药膜,加之细胞增殖的调控、分子生物学产品以及中药的发展,使它们不但抑制了外源性愈合,还促进了内源性愈合。本文对近年来国内外有关肌腱修复术后肌腱粘连的防治研究进展作一综述。     

The effect of platelet‐rich plasma on the neovascularization of surgically created equine superficial digital flexor tendon lesions

The repair process of tendon injuries, which are common in both human and equine athletes, is slow and the quality of the repair tissue is often inferior to the original tendon tissue, which frequently leads to re‐injury. The relatively poor vascularization of tendons is considered to be one of the reasons for their limited healing potential. Recently, platelet‐rich plasma (PRP), an autologous concentrate of platelets, rich in growth factors, has been shown to enhance the repair process of injured tendons. This effect has been ascribed to the high levels of growth factors in PRP, several of which are known to be involved in tendon repair. Among many other growth factors, the vascular endothelial growth factor, a powerful stimulator of angiogenesis, is abundantly present in PRP, suggesting that enhancement of neovascularization might be one of the working mechanisms. In this study, the effect of PRP on neovascularization was studied in experimentally induced tendon injuries using color Doppler ultrasonography and immunological staining of Factor VIII. PRP induced significantly more neovascularization than the placebo treatment until at least 23 weeks after treatment, as detected by both Doppler ultrasonography and Factor VIII staining. Neovascularization might be one of the explanations for the long‐lasting effect of a single intratendinous treatment with PRP.     

The use of biological agents toaccelerate recovery from rotator cuff repair: Path to clinical application

Injury to the rotator cuff tendons is a common cause of pain and disability in the upper extremity. The supraspinatus tendon is frequently torn, either as a direct result of trauma alone or through trauma following attritional changes. When surgical repair is performed, patients all too often regain only limited shoulder motion. One probable reason for lingering stiffness is that active shoulder rehabilitation is delayed for weeks following surgery for fear of disrupting the repair. Recent research aimed at hastening the healing of muscle, ligaments, and tendons through the application of biological agents called growth factors focuses on boosting natural repair processes, thereby facilitating accelerated rehabilitation and return to function. Less long-term stiffness can be expected when earlier active motion is undertaken, with the end result being both an earlier and a more functional return to unrestricted activity. In this article, we propose a new approach to accelerating functional recovery following rotator cuff repair, using exogenous application of biological agents to boost tendon healing.     

Cyclic mechanical stretching enhances secretion of Interleukin 6 in human tendon fibroblasts

Accelerated rehabilitation after tendon and ligament injuries is widely accepted to avoid adverse effects of immobilization. However, progressive rehabilitation may also lead to an excessive inflammatory soft tissue response. To investigate the amount of loading necessary to accelerate the healing process without causing damage to the healing tissue, we experimentally stretched human tendon fibroblasts of healthy tendons 15 and 60 min with 1 Hz and an elongation of 5% and measured the secretion of interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-alpha), transforming growth factor beta1 (TGF-beta1), platelet-derived growth factor (PDGF), and fibroblast growth factor basic (bFGF). Secretion of IL-6 was significantly induced by 15 min of cyclic biaxial mechanical stretching after 4 and 8 h observation time and by 60 min stretching and 2 h observation time. The growth factors TGF-beta1, bFGF, and PDGF were secreted by human tendon fibroblasts both in stretched cells and controls; however, no increases were related to mechanical stretching. There was no measurable secretion of TNF-alpha in human tendon fibroblasts. These findings suggest that the inflammatory reaction often seen during physiotherapy after tendon and ligament injuries is caused in part by secretion of IL-6 from the stretched human tendon fibroblasts. IL-6 may cause exaggerated proliferation of fibroblasts and synovial cells as seen in rheumatoid arthritis and arthrofibrosis. However, physiological proliferative reactions leading to repair of injured tissue are also possible. IL-6 measured in the synovial fluid may be an important predictor for monitoring and improving therapeutic strategies in terms of tendon/ligament healing.     

船员屈指肌腱损伤的治疗

目的探讨船员屈指肌腱损伤的特点和治疗方法。方法对本院收治的５２例船员屈指肌腱损伤临床资料进行总结并着重对治疗效果进行分析。结果本组Ⅰ期修复４３例１６８条,Ⅱ期修复９例２４条。术中用套圈缝合法或改良Ｋｅｓｓｌｅｒ法缝接肌腱,Ⅱ期行粘连肌腱松解术８例２５条,术后２４小时开始功能锻炼。治疗效果经对４３例１４６条随访３个月～３年（平均１年６个月）,根据ＴＡＭ疗效标准评定为：锐割伤５７条中,优４７条,良８条,中２条,优良率为９６．５％;缆绳绞轧伤３６条中,良２１条,中９条,差６条,优良率为５８．３％;压榨断开伤５３条中,优２９条,良１６条,中６条,差２条,优良率为８４．９％。结论屈指肌腱损伤疗效与损伤类型关系密切。锐器切割伤疗效最佳,缆绳绞轧伤最差。对缆绳绞轧伤应积极创造条件,采取相应措施,以提高其疗效     

Effect of ultrasound therapy on the repair of Achilles tendon injuries in rats

The purpose was to determine the effects of selected regimens of ultrasound therapy on the rates of repair of injured Achilles tendons of rats. Specific dependent variables examined were tendon breaking strength and rate of collagen formation. A puncture technique was used to induce injuries to both Achilles tendons of rats. Continuous ultrasound was administered to the left tendon for 4 min per treatment session at an intensity of 1.5 W.cm-2. Rats were sacrificed 2, 5, 9, 15, and 21 d following injury for measurement of tendon breaking strength and 3 and 5 d postinjury for analysis of collagen synthesis. Breaking strength was defined as the minimum force required to completely rupture the tendon. Collagen synthesis was indicated by the conversion of labeled proline to hydroxyproline. The breaking strengths of the treated tendons were significantly greater than strengths of the untreated tendons 5, 9, 15, and 21 d postinjury. Collagen synthesis was increased in the treated tendons compared with the untreated tendons 5 d postinjury. The results indicate that ultrasound treatment increases the rate of repair of injured Achilles tendons of rats. The results are also consistent with an association between increased collagen synthesis and greater breaking strength during tendon repair.     

Biomechanics and pathophysiology of overuse tendon injuries: ideas on insertional tendinopathy

Tendons behave viscoelastically and exhibit adaptive responses to conditions of increased loading and disuse. High-resolution, real-time ultrasound scanning confirms the applicability of these findings in human tendons in vivo. In addition, recent biomechanical studies indicate that strain patterns in tendons may not be uniform, as tendons show stress-shielded areas and areas subjected to compressive loading at the enthesis. These areas correspond to the sites where tendinopathic characteristics are typically seen. This indicates that some tendinopathies may, paradoxically, be considered as 'underuse' lesions despite the common beliefs that they are overuse injuries. Classic inflammatory changes are not frequently seen in chronic athletic tendon conditions and histopathology features in tendinopathic tendons are clearly different from normal tendons, showing an exaggerated dysfunctional repair response. Tendinopathies are traditionally considered overuse injuries, involving excessive tensile loading and subsequent breakdown of the loaded tendon. Biomechanical studies show that the strains within the tendons near their insertion site are not uniform. If the material properties are similar throughout the tendon, forces transferred through the insertion site preferentially load the side of the tendon that is usually not affected initially in tendinopathy. In that case, the side affected by tendinopathy is generally 'stress shielded'. Thus, the presence of differential strains opens the possibility of alternative biomechanical explanations for the pathology found in these regions of the tendon. The traditional concept of tensile failure may not be the essential feature of the pathomechanics of insertional tendinopathy. Certain joint positions are more likely to stress the area of the tendon commonly affected by tendinopathy. Incorporating different joint position exercises may exert more controlled stresses on these affected areas of the tendon, possibly allowing better maintenance of the mechanical strength of that tendon region and, therefore, prevent injury. Such exercises could stress a healing area of the tendon in a controlled manner and thus stimulate healing once an injury has occurred. Additional work is needed to prove whether such principles should be incorporated in current rehabilitation techniques.     

The role of stretching in tendon injuries

The function of tendons can be classified into two categories: tensile force transmission, and storage and release of elastic energy during locomotion. The action of tendons in storing and releasing energy is mainly seen in sports activities with stretch-shortening cycles (SSCs). The more intense the SSC movements are (jumping-like activities), the more frequently tendon problems are observed. High SSC movements impose high loads on tendons. Consequently, tendons that frequently deal with high SSC motion require a high energy-absorbing capacity to store and release this large amount of elastic energy. As the elasticity of tendon structures is a leading factor in the amount of stored energy, prevention and rehabilitation programmes for tendon injuries should focus on increasing this tendon elasticity in athletes performing high SSC movements. Recently, it has been shown that ballistic stretching can significantly increase tendon elasticity. These findings have important clinical implications for treatment and prevention of tendon injuries.     

Operative treatment of peroneusbrevis and peroneus longus tendon tears

The peroneal tendons provide important functions to the foot and ankle including stabilization of the lateral ankle and plantar flexion of the first ray. Injury to the peroneal tendons might occur as a result of an ankle or peroneal tendon instability or a local degenerative process. Conservative management for peroneal tendon tears is not uniformly successful and surgical management remains a common method for treatment. The peroneal tendon rupture might be treated by simple repair of isolated longitudinal rupture, by excision of degenerative tendon and longitudinal repair of the remaining tendon, or by excision of degenerative tendon and side-to-side tenodesis for extensive tendon damage. Stability of the tendons also is addressed by bony and or soft tissue stabilization procedures.     

Neovascularisation in chronic tendon injuries detected with colour Doppler ultrasound in horse and man: implications for research and treatment

Recent research on chronic painful Achilles tendons in humans using ultrasonography and immunohistochemistry, has demonstrated an association between neurovascular ingrowth and tendon pain. In horses, chronic debilitating tendon conditions are well-known to be very difficult to treat, and the background to impaired function and pain is not scientifically clarified. In a collaborative research project between the Sports Medicine Unit in Umeå and Strömsholm Equine Hospital, grey-scale ultrasonography (US) and colour Doppler (CD) examination were performed in ten horses with chronic tendon injuries (>3 months) and a control group of six healthy and asymptomatic horses. In all symptomatic tendons, but not in any of the tendons in the control group, neovessels were seen in the area with structural tendon changes. The neovessels found in the horse tendons looked similar to what has recently been presented in human Achilles tendons. These findings motivate evaluation of the same treatment, a sclerosing injection that was demonstrated recently to give promising results in the treatment of chronic Achilles tendon injuries (tendinosis) in humans.