The behavior of neuronal cells on tendon-derived collagen sheets as potential substrates for nerve regeneration

Peripheral nervous system injuries result in a decreased quality of life, and generally require surgical intervention for repair. Currently, the gold standard of nerve autografting, based on the use of host tissue such as sensory nerves is suboptimal as it results in donor-site loss of function and requires a secondary surgery. Nerve guidance conduits fabricated from natural polymers such as collagen are a common alternative to bridge nerve defects. In the present work, tendon sections derived through a process named bioskiving were studied for their potential for use as a substrate to fabricate nerve guidance conduits. We show that cells such as rat Schwann cells adhere, proliferate, and align along the fibrous tendon substrate which has been shown to result in a more mature phenotype. Additionally we demonstrate that chick dorsal root ganglia explants cultured on the tendon grow to similar lengths compared to dorsal root ganglia cultured on collagen gels, but also grow in a more oriented manner on the tendon sections. These results show that tendon sections produced through bioskiving can support directional nerve growth and may be of use as a substrate for the fabrication of nerve guidance conduits.     

聚乳酸防粘连膜在Ⅱ区屈肌腱损伤修复中的临床应用

目的观察可吸收性防粘连膜预防肌腱粘连的临床应用效果。方法对23例手部屈肌腱II区损伤修复后的患者随访,分为置膜组(A组)和对照组(B组),A组用粘克聚-DL-乳酸可吸收医用膜包绕肌腱缝合端,B组不放置防粘连膜,4~6周后均行主动屈伸指锻炼。采用MRC(Medical Research Council)、TAM(Total Active Motion)、Strickland System和Buck-Gramcko System 4种评价方法对屈指深肌腱修复后的功能进行评定。结果术后随访时间1.5~12个月,平均3个月。在屈肌腱肌力MRC评定中,A组优良率为66.6%,B组优良率为58.3%;对于TAM评级,A组优良率为66.6%,B组优良率为50.0%;在Strickland评级中,A组优良率为80.0%,B组优良率为58.3%;在Buck-Gramcko系统评定中,A组优良率为86.7%,B组优良率为41.7%。前三项评级0.05;Buck-Gramcko系统评定中,0.05,A组和B组有统计学差异。结论在II区屈肌腱损伤修复中,聚乳酸防粘连膜具有良好的预防肌腱粘连的作用。     

Lysyl oxidase-mediated collagen crosslinks may be assessed as markers of functional properties of tendon tissue formation

Mechanical property elaboration of engineered tissues is often assumed on the basis of gene and protein characterizations, rather than mechanical testing. However, we recently demonstrated that mechanical properties are not consistently correlated with matrix content and organization during embryonic tissue development. Based on this, mechanical properties should be assessed independently during natural or engineered tissue formation. Unfortunately, mechanical testing is destructive, and thus alternative means of assessing these properties are desirable. In this study, we examined lysyl oxidase (LOX)-mediated crosslinks as markers for mechanical properties during embryonic tendon formation and the potential to detect them non-destructively. We used tandem mass spectrometry (LC-MS/MS) to quantify changes in hydroxylysyl pyridinoline (HP) and lysyl pyridinoline (LP) crosslink density in embryonic chick tendon as a function of developmental stage. In addition, we assessed a multiphoton imaging approach that exploits the natural fluorescence of HP and LP. With both techniques, we quantified crosslink density in normal and LOX-inhibited tendons, and correlated measurements with mechanical properties. HP and LP crosslink density varied as a function of developmental stage, with HP-to-dry mass ratio correlating highly to elastic modulus, even when enzymatic crosslink formation was inhibited. Multiphoton optical imaging corroborated LC-MS/MS data, identifying significant reductions in crosslink density from LOX inhibition. Taken together, crosslink density may be useful as a marker of tissue mechanical properties that could be assessed with imaging non-destructively and perhaps non-invasively. These outcomes could have significant scientific and clinical implications, enabling continuous and long-term monitoring of mechanical properties of collagen-crosslinked tissues or engineered constructs.     

电针傍刺经筋结点治疗缺血性脑卒中急性期上肢偏瘫的临床研究

目的通过观察电针傍次上肢经筋结点治疗缺血性脑卒中急性期上肢偏瘫的临床疗效,探讨电针傍次经筋结点治疗缺血性卒中急性期肢体瘫痪的作用机制。方法60例缺血性卒中急性期偏瘫的患者采用SPSS软件随机数字生成器分为治疗组与对照组各30例。治疗组采用电针傍刺上肢经筋结点治疗,对照组采用电针上肢常规经穴治疗。分别于治疗前后观察评价两组上肢的肌力(MMT徒手肌力评定法)、关节活动度(ROM关节活动度评定法)、运动功能(Fugl-Meyer运动功能评分量表、ARAT上肢动作研究量表)、临床神经功能缺损程度(NIHSS量表)确定疗效。结果两组患者治疗后ROM评分下降,Barthel指数、Fugl-Meyer评分、ARAT评分均上升。治疗组较对照组ROM评分、Barthel指数、Fugl-Meyer评分、ARAT评分改善更优(P<0.05);疗程结束后治疗组肌力经MMT评定后有效率为90%,高于对照组的76.67%(P<0.05);治疗组疗效经神经功能缺损程度评价有效率为93.33%,高于对照组76.67%(P<0.05)。结论电针傍刺经筋结点与常规针刺治疗都可以改善缺血性卒中急性期上肢瘫痪,但电针傍刺经筋结点治疗效果更佳。     

手部肌腱损伤与修复:737例流行病学因素分析

背景:目前国内外针对手部肌腱损伤所开展的流行病学调查鲜有报道.在新疆范围内,屈伸指肌腱损伤的患者呈逐年上升趋势,但对其受伤、治疗乃至预后较完整的流行病学调查极为罕见.目的:分析手部肌腱损伤患者的流行趋势及预后分布特征,了解手部肌腱损伤患者的预后功能恢复,有针对性地开展人群干预,提高干预效果,探讨屈伸指肌腱损伤因素与预后...     

Tissue fixation security in transosseous rotator cuff repairs: A mechanical comparison of simple versus mattress sutures

The primary purpose of this investigation was to compare tissue fixation security by simple sutures versus mattress sutures in transosseous rotator cuff repair. These two repair techniques were each performed in 17 human cadaver shoulders, with two bone tunnels being used for the repair by two simple sutures and two other bone tunnels being used for the repair by one mattress suture. The repairs were loaded to failure in a servohydraulic materials test system. Rotator cuff repair by simple sutures was found to be significantly stronger than repair by mattress sutures (P = .0007). The average ultimate load to failure for the simple suture construct (189.62 N) was 39.72% greater than that for the mattress suture construct (135.71 N). Most of the failures occurred by suture breakage at the knot. Load-sharing by multiple suture tails and multiple knots in the simple suture configuration likely contributed to its superior strength characteristics compared with the mattress suture configuration.     

Is there significant variation in the material properties of four different allografts implanted for ACL reconstruction

The aims of our study were to: (1) determine if there are differences in the material properties of tendon obtained from implanted tibialis anterior, achilles, bone-patella- bone and tibialis posterior allografts; (2) determine the variability in material properties between the implanted specimens. A total of 60 specimens were collected from fresh frozen allografts implanted at ACL reconstruction. Specimens collected included 15 tibialis anterior, 15 tibialis posterior, 15 achilles and 15 bone-patella-bone tendons. Each specimen was mounted in a custom made cryogrip. The mounted specimens were loaded onto a MTS Testline servo-hydraulic testing machine in a uni-axial tensile test configuration. Specimens were subjected to a strain rate of 5% per second until the ultimate tensile stress (UTS), failure strain and high strain modulus was calculated for each specimen after being normalized for specimen dimensions. Individual material properties were tested using one way analysis of variance (ANOVA) and post hoc Tukey’s B test with a P value of <0.05 considered significant. Homogeneity of variance was assessed using the Levene’s test. As a result, no significant difference was found between all four grafts with regards to UTS, failure strain or high strain linear modulus. The UTS was plotted against the modulus demonstrating a linear relationship which is typical of soft tissues. Significant variability in the results were observed. In conclusion, there was no significant statistical difference between the material properties of the four tendon allografts tested. But significant variability in results was observed within groups and between groups, which may provide one explanation for the range of results in allograft ACL reconstruction reported in the literature.