肩袖肌腱损伤动物模型的建立及初步研究

目的:采用兔肩胛下肌建立肩袖肌腱损伤动物模型,验证其可行性并进行肩袖肌腱损伤生物力学、组织学研究。方法:40只成熟雄性新西兰大白兔随机编号,选取4只不进行任何处理,用于前期准备及调试工作,其数据不计入实验结果;其余36只均行右侧肩胛下肌部分离断,建立肩袖部分损伤模型,对侧行假手术进行对照。术后不限制活动。分别于术后2、4、6、8周行肩关节MRI观察肩袖肌腱愈合情况;采用HE染色观察肌腱愈合情况;采用Masson染色观察组织中肌纤维愈合情况;采用生物力学测试检测肌腱强度。结果:兔肩胛下肌具有与人相似的解剖结构和组织结构,适用于建立肩袖损伤模型,手术操作过程简便,可重复性高。除去实验麻醉死亡4只,实验动物右侧肌腱损伤后8周,HE染色及Masson染色可观察到肌腱基本愈合;MRI检查显示肌腱内信号均匀,关节腔内基本无高信号影。生物力学结果显示术后2、4、6周肌腱最大载荷均低于假手术侧,差异有统计学意义(P<0.05),术后8周肌腱最大载荷与假手术侧差异无统计学意义(P>0.05)。结论:兔肩袖肌腱损伤8周时,基本恢复正常的肌腱排列结构,肌腱的生物力学强度基本恢复正常。采用兔肩胛下肌建立肩袖损伤模型适用于肩袖疾病的研究。     

肌腱干/祖细胞和生长因子促进肌腱愈合的作用机制研究进展

肌腱损伤常需手术治疗,能够一定程度上恢复肌腱的结构与稳定性,但往往难以恢复到正常的强度,其主要原因是肌腱自然愈合能力有限,修复后的肌腱不能完全恢复功能.随着对肌腱愈合的研究不断加深,生物学技术为肌腱修复提供了新的方向.当前对肌腱修复的研究热点之一是使用生物辅助物来促进肌腱愈合,这些辅助物包括肌腱干/祖细胞(TSPCs)...     

重建腱周组织一期修复指伸肌腱断裂的疗效分析

目的探讨在指伸肌腱修复术中重建腱周组织减少肌腱粘连的方法。方法指伸肌腱损伤68例分为A、B两组（按配对设计原则）,应用显微外科技术一期修复损伤。A组修复腱旁组织、深筋膜;B组不修复腱旁组织,仅修复深筋膜。术后早期进行保护性功能锻炼。术后随访3～12个月。结果术后6个月按美国手外科学会总主动活动度（TAM）系统评定方法评定疗效：A组优26例,良7例,可1例,优良率97.06%。B组优20例,良6例,可8例,优良率76.47%。两组优良率比较差异有统计学差异（P〈0.05）,A组效果优于B组。结论新鲜的指伸肌腱损伤,应用显微外科技术一期缝合腱旁组织,能更好地促进肌腱功能的恢复。     

生物膜重建腱鞘防止手屈肌腱粘连40例临床分析

生物膜重建腱鞘防止手屈肌腱粘连４０例临床分析武警河北总队医院外三科（石家庄０５００８１）牛艳辉，邵新中，孟凡军，李超发，赵杰，李红旗，郑修存关键词生物膜，腱鞘，手屈肌键，修复手屈肌腱损伤修复后，在保证肌腱愈合的前提下，减少与周围组织粘连，恢复滑动功能...     

早期活动对肌腱和韧带修复的影响

肌腱、韧带损伤和断裂后修复的好坏直接关系到损伤部位的功能。对于一般人来说只要能够恢复韧带和肌腱的连续性和一般功能也就算治疗满意了。而对运动员来说,则要求恢复肌腱和韧带的良好功能,而     

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。     

肌腱内横向结扎缝合法修复肌腱的生物力学实验研究

目的：对不同方法修复肌腱的生物力学进行研究以使修复肌腱有足够张力强度．方法：对兔跟腱一侧用肌腱内横向结扎缝合法缝合（实验组），对侧用Ｋｅｓｓｌｅｒ法缝合（对照组），术后０～５周，经手术显微镜、光镜及电镜观察，并进行详细的生物力学性能测试．结果：（１）组织学观察实验组优于对照组．（２）实验组载荷、强度极限、拉伸刚度、比能及应变率分别较对照组高４８．４％、５５．３％、３３．９％、７９．２％及４６．９％，统计学分析有非常显著性差异（Ｐ＜０．０１）．结论：肌腱愈合过程中，修复方法与其生物力学性能恢复有关，该法修复的肌腱力学性能好     

采用骨-韧带-骨移植重建腕舟月韧带

在腕关节的诸多骨间韧带中，舟月韧带(scapholunate interosseous ligament，SLIL)最易受到损伤。而陈旧性SLIL损伤的修复与重建一直是临床工作中比较棘手的难题，这类损伤由于难以进行韧带的直接缝合或止点重建，既往常用关节囊紧缩和肌腱编织的方法，不仅手术切口和创伤较大，而且会对供区组织功能造成一定的损害。更为重要的是，这类重建方法不能恢复SLIL解剖形态，从而在生物力学特性和生理功能上难以令人满意。     

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。     

电场促进兔肌腱愈合实验研究

电刺激已被证实有增强各种组织再生作用。本实验应用方形波耦合电场刺激一侧损伤的兔屈趾深肌腱,并与未受电刺激的对侧进行比较。于损伤后不同时期分别测定腱内羟脯氨酸含量、光学显微镜下组织学检查及测试腱修复处愈合强度。统计学处理后证实经该电场刺激后在第14、21和42天可提高腱内羟脯氨酸含量,第42天时腱愈合强度明显高于非刺激侧,组织学检查表明该电场刺激可增强损伤肌腱的早期愈合反应及加快恢复腱内胶原定向排列结构。     

中医药治疗跟腱运动损伤的实验研究

通过对大强度训练后兔跟腱的组织学和生物力学观察，发现跟腱随训练发生不同程度的运动损伤，同时伴有某些生物力学性质的增强，中医药对这些损伤的治疗效果明显。     

The response of rabbit patellar tendons after autologous blood injection.

PURPOSE: Blood is a rich source of growth factors that can stimulate fibrocyte migration and help induce neovascular ingrowth. These properties may be able to stimulate a healing response in chronic degeneration of a tendon (tendonosis). The purpose of this study was to assess the biomechanical and histological effects of autologous blood injection on animal tendons. METHODS: New Zealand white rabbit left side patellar tendons were injected with 0.15 cc of autologous blood. We then compared the mechanical properties and histology to the normal right patellar tendon at 6 and 12 wk. RESULTS: At 6 and 12 wk after the injection, there were no differences in the histology compared with normal tendon tissue, and there were no significant changes in tendon stiffness. Biomechanically, the tendons were not damaged at 6 wk after the injection. By 12 wk, tendons that were injected with blood were significantly (P < 0.014) stronger. CONCLUSION: We found that injecting blood directly into normal tendons appears safe. Further evaluation of this technique would appear indicated.     

Does immobilization after radiofrequency-induced shrinkage influence the biomechanical properties of collagenous tissue? An in vivo rabbit study

BACKGROUND: Despite widespread use of radiofrequency-induced shrinkage of collagenous tissue, there have been no animal studies on the effects of postoperative immobilization on the biomechanical behavior of shrunken tissue. PURPOSE: To examine the role of postoperative immobilization after radiofrequency-induced shrinkage, with special emphasis on the biomechanical properties of shrunken collagenous tissue. STUDY DESIGN: Controlled laboratory study. METHODS: One patellar tendon of 66 New Zealand White rabbits was shrunk. Six rabbits were sacrificed immediately after surgery. Twenty rabbits were not immobilized, twenty were immobilized for 3 weeks, and twenty were immobilized for 6 weeks. The biomechanical parameters failure strength, stiffness, and relaxation were tested. RESULTS: Nine weeks after surgery, biomechanical parameters were still low compared to control tendons. Shrunken tendons did not reach levels of normal tissue at any time after surgery, regardless of whether the animals had been immobilized. According to time-related development, all biomechanical parameters had the lowest levels 3 weeks after surgery. Immobilized tendons demonstrated a better and faster recovery than nonimmobilized tendons compared to the immediate postoperative level. CONCLUSION: Postoperative immobilization supports recovery of biomechanical properties after shrinkage. Despite immobilization, biomechanical properties of shrunken tissue did not completely reach levels of normal tissue. CLINICAL RELEVANCE: Careful rehabilitation is imperative after radiofrequency-induced shrinkage. This animal model supports an immobilization period of at least 6 weeks after surgery.     

Compression etiology in tendinopathy

Recent studies have emphasized that the etiology of tendinopathy is not as simple as was once thought. The etiology is likely to be multifactorial. Etiologic factors may include some of the traditional factors such as overuse, inflexibility, and equipment problems; however, other factors need to be considered as well, such as age-related tendon degeneration and biomechanical considerations as outlined in this article. More research is needed to determine the significance of stress-shielding and compression in tendinopathy. If they are confirmed to play a role, this finding may significantly alter our approach in both prevention and in treatment through exercise therapy. The current biomechanical studies indicate that certain joint positions are more likely to place tensile stress on the area of the tendon commonly affected by tendinopathy. These joint positions seem to be different than the traditional positions for stretching exercises used for prevention and rehabilitation of tendinopathic conditions. Incorporation of different joint positions during stretching exercises may exert more uniform, controlled tensile stress on these affected areas of the tendon and avoid stresshielding. These exercises may be able to better maintain the mechanical strength of that region of the tendon and thereby avoid injury. Alternatively, they could more uniformly stress a healing area of the tendon in a controlled manner, and thereby stimulate healing once an injury has occurred. Additional work will have to prove if a change in rehabilitation exercises is more efficacious that current techniques.     

A nonlinear rheological assessment of muscle recovery from eccentric stretch injury

PURPOSE: To better understand the mechanical behavior of healing skeletal muscle; specifically the tissue's response after acute eccentric stretch injury. METHODS: Rabbit tibialis anterior (TA) muscle tendon units were subjected to an in vivo single stretch (eccentric) injury and mechanically evaluated (constant rate elongation to failure) at 1, 3, and 7 d postinjury. In addition to a traditional linear analysis (linear stiffness and failure load), an existing nonlinear rheological model was modified to interpret the experimental load-to-failure data. The models' performance were evaluated and discussed. RESULTS: No significant injury effect was observed, either within or between groups, across the 7-d healing interval, using the linear analysis. However, interpretation of the data using our nonlinear phenomenological model identified significant changes in mechanical behavior that went undetected by linear analyses. Percent differences, between injured and contralateral control limbs, of model parameter estimates were analyzed. Nonparametric statistical analysis illustrated significant changes in the first-order stiffness (k1) throughout the 7-d healing interval. Model simulations using mean values of each parameter revealed increased low-load tissue compliance after injury, with a decrease in linear slope that recovered steadily toward control values by day 7. At 7 d postinjury, virtually no differences were observed between injured and sham control tissues. CONCLUSIONS: Our findings suggest that acute eccentric injury increases the muscle's compliance 24 h after injury, with a steady recovery to uninjured values by the 7th day, yet these changes went undetected by linear analysis. Therefore, nonlinear analysis is necessary to recognize valuable information contained in the low-load region and to quantify important biomechanical phenomena of stretch-injured healing skeletal muscle.     

The effects of augmentation with Swine small intestine submucosa on tendon healing under tension: histologic and mechanical evaluations in sheep

BACKGROUND: Rotator cuff failure after surgery may be attributed to inferior tissue healing properties that result from repetitive cyclic loading during early rehabilitation. Enhancing the biological healing process may reduce the incidence of failures after rotator cuff repairs. HYPOTHESIS: Augmentation of rotator cuff tissue using swine small intestine submucosa in a sheep model will improve the rate and quality of tissue repair. STUDY DESIGN: Controlled laboratory study. METHODS: We resected and reattached 26 sheep infraspinatus tendons under tension, with 13 animals receiving a small intestine submucosa patch (augmented group). Animals were sacrificed at 12 weeks, and biomechanical testing and histologic evaluation were performed. Biomechanical testing was completed in 10 tendons from each group. Specimens were loaded to failure at a constant displacement to obtain the load deformation curve used to calculate load to failure and stiffness of the healed bone-tendon interface. Histologic testing addressed tissue healing at the bone-tendon interface. RESULTS: The load-to-failure data did not indicate a significant difference between the augmented and nonaugmented groups (1252 +/- 402 N vs 985 +/- 459 N, respectively; P > .05). However, the augmented group had significantly better stiffness than the nonaugmented group (215 +/- 44 N/mm vs 154 +/- 63 N/mm, respectively; P = .03). Histologic data revealed that the infraspinatus tendon in all specimens inserted into the bone through a zone of fibrocartilage, although none of the patches were intact. CONCLUSION: Although there were no differences in the load-to-failure data between the 2 groups, the statistically significant improvement in stiffness for the augmented group is clinically relevant. Stiffness is the biomechanical parameter representing the tissue response to subdestructive loads seen with early rehabilitation. Augmenting the repair with a collagen matrix improved the early healing characteristics of the repair construct. CLINICAL RELEVANCE: Enhancing the biological process of tendon healing under tension by using a collagen matrix patch may improve the ultimate success of rotator cuff repair.     

“Soft, hard, or just right?” Applications and limitations of axial-strain sonoelastography and shear-wave elastography in the assessment of tendon injuries

Injury to a tendon leads to alterations in the mechanical properties of the tendon. Axial-strain sonoelastography and shear-wave elastography are relatively new, real-time imaging techniques that evaluate the mechanical properties of tendons in addition to the existing morphological and vascular information that is obtained with traditional imaging tools. Axial-strain sonoelastography displays the subjective distribution of strain data on an elastogram caused by tissue compression, whereas shear-wave elastography provides a more objective, quantitative measure of the intrinsic tissue elasticity using the acoustic push-pulse. Recent studies suggest that axial-strain sonoelastography is able to distinguish between asymptomatic and diseased tendons, and is potentially more sensitive than conventional ultrasound in detecting early tendinopathy. Shear-wave elastography seems to be a feasible tool for depicting elasticity and functional recovery of tendons after surgical management. While initial results have been promising, axial-strain sonoelastography and shear-wave elastography have not yet found routine use in wider clinical practice. Possible barriers to the dissemination of axial-strain sonoelastography technique include operator dependency, technical limitations such as artefacts and lack of reproducibility and quantification of sonoelastography data. Shear-wave elastography may improve the reproducibility of elastography data, although there is only one published study on the topic to date. Large-scale longitudinal studies are needed to further elucidate the clinical relevance and potential applications of axial-strain sonoelastography and shear-wave elastography in diagnosing, predicting, and monitoring the progress of tendon healing before they can be widely adopted into routine clinical practice.     

The role of pro-inflammatory and immunoregulatory cytokines in tendon healing and rupture: new insights

Owing to limited self-healing capacity, tendon ruptures and healing remain major orthopedic challenges. Increasing evidence suggests that post-traumatic inflammatory responses, and hence, cytokines are involved in both cases, and also in tendon exercise and homeostasis. This review summarizes interrelations known between the cytokines interleukin (IL)-1β, tumor necrosis factor (TNF)α, IL-6 and vascular endothelial growth factor (VEGF) in tendon to assess their role in tendon damage and healing. Exogenic cytokine sources are blood-derived leukocytes that immigrate in damaged tendon. Endogenous expression of IL-1β, TNFα, IL-6, IL-10 and VEGF was demonstrated in tendon-derived cells. As tendon is a highly mechanosensitive tissue, cytokine homeostasis and cell survival underlie an intimate balance between adequate biomechanical stimuli and disturbance through load deprivation and overload. Multiple interrelations between cytokines and tendon extracellular matrix (ECM) synthesis, catabolic mediators e.g. matrix-degrading enzymes, inflammatory and angiogenic factors (COX-2, PGE2, VEGF, NO) and cytoskeleton assembly are evident. Pro-inflammatory cytokines affect ECM homeostasis, accelerate remodeling, amplify biomechanical adaptiveness and promote tenocyte apoptosis. This multifaceted interplay might both contribute to and interfere with healing. Much work must be undertaken to understand the particular interrelation of these inflammatory and regulatory mediators in ruptured tendon and healing, which has relevance for the development of novel immunoregulatory therapeutic strategies.