Asymmetric atrophy of the supraspinatus muscle following tendon tear.

Muscle atrophy is a known consequence of muscle disuse, muscle denervation and tendon tear. Whereas after nerve injury muscle atrophies in the denervated area, the distribution of muscle atrophy following tear of its tendon is not known. Standardized MRI scans of 64 consecutive, painful shoulders were evaluated for supraspinatus tendon tearing, myotendinous retraction, supraspinatus muscle atrophy, fatty infiltration, ratio of the scapular (deep) and fascial (superficial) muscle area ("symmetry") and position of the central tendon within the supraspinatus fossa. There were thirteen shoulders with no and eleven shoulders with partial thickness supraspinatus tendon tears. In the forty cases with full thickness tendon tear, there was significant muscle atrophy and fatty infiltration. Atrophy of the fascial muscle portion was 43%, on the bony side it was 9% (p<0.005). The position of the central tendon within the supraspinatus fossa, was unaltered. Muscular changes following tendon tear occur highly asymmetrically: the muscle portion originating from the fascia primarily atrophies, the portion originating from the scapula primarily undergoes fatty infiltration. Muscular changes are not simply a consequence of muscle disuse, but dependent on architectural changes in the muscle.     

Bilateral patellar tendon rupture without predisposing systemic disease or steroid use: a case report and review of the literature

Simultaneous bilateral patella tendon ruptures are very rare injuries of the knee extensor complex often associated with systemic disorders such as lupus erythematosus or rheumatoid arthritis. We describe the case of a 34-year-old man without concomitant systemic disease or steroid use and provide the most comprehensive review of the German and English literature. Furthermore, we discuss the predisposing factors and causal mechanisms as well as current diagnostic procedures and treatment options. In the literature review, only a few patients without systemic disorder or steroid medication present with potential predisposing factors that may be responsible for degenerative changes of the patella tendon, weakening its stability. In addition, in most of these cases, it remains difficult to explain the bilateral and simultaneous nature of this injury.     

Ultrastructural aspects of degenerative tendinopathy

Summary The authors describe changes in the ultrastructure of degenerate tendon that has undergone spontaneous rupture.The cellular elements show alteration of shape and widespread fatty degeneration. The cytoplasmic organules (mitochondria, rough endoplasmic reticulum, Golgi apparatus) are often completely absent, proof of a reduced metabolic activity of the cells.The matrix also shows serious degenerative phenomena with irregular orientation of the collagen fibrils frequently with variation in diameter, fraying and absence of periodicity.

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Résumé Les auteurs décrivent les modifications de la structure microscopique des tendons dégénérés qui ont été le siège d'une rupture spontanée.Les éléments cellulaires sont déformés et témoignent d'une dégénérescence graisseuse étendue. Les organes cytoplasmiques (mitochondries, réticulum endoplasmique granuleux, appareil de Golgi) ont souvent disparu, ce qui est la preuve d'une diminution de l'activité métabolique des cellules.Il existe également d'importants phénomènes dégénératifs au niveau de la matrice, avec orientation irrégulière des fibres de collagène, qui présentent des variations de diamètre, un aspect effiloché et une absence de périodicité.

     

Gene transfer to the tendon-bone insertion site

This study investigated whether gene transfer to the tendon-bone insertion site is possible during early tendon-transplant healing using viral vectors. In addition, we evaluated the optimal gene delivery technique for an in vivo adenoviral gene transfer to a tendon-bone insertion site in a bone tunnel. Twenty-six rabbits underwent a bilateral transfer of the flexor digitorum longus tendon into a bone canal in the calcaneus. The animals were divided into two groups. The first group (n=18) received a direct injection of an adenoviral vector carrying the luciferase marker gene into the tendon on the left side, while on the right side the adenoviral vector was first injected into the bone trough and the tendon was later inserted into the trough. The analysis of this experiment showed that over a 4-week period a higher luciferase activity was achieved using the bone trough immersion technique. In the second group (n=8) we therefore used the qualitative marker virus (Ad/-LacZ) with the bone trough immersion technique in order to show the site of gene expression. The histological analysis of this experiment demonstrated the presence of -galactosidase positive cells within the tendon-bone interface over a 4-week period. Therefore we showed in the first part of this study that the bone canal provides a more efficient target for direct adenoviral gene delivery than the tendon. In the second part of the study we demonstrated the feasibility of the bone trough immersion technique since sustained gene expression within the tendon-bone interface was obtained for up to 4 weeks. This study has shown the feasibility of gene delivery to the tendon-bone interface and provides the basis for the application adenoviral delivery of growth factor genes to the tendon-bone insertion site.     

A novel solution for the notorious long-leg cylinder cast

Although the long-leg cylinder cast is an effective means of immobilization, it is prone to distal migration which commonly results in skin compromise. Described here is a simple technique that involves using adhesive tape as a suspension mechanism. This technique is clinically effective, has a low complication rate and requires only a small diversion from standard practice.     

Spontaneous healing process of a supraspinatus tendon tear in rabbits

Introduction The rotator cuff has a characteristic structure, in that one surface faces articular cartilage and another faces bursa. This structure may produce differences in the healing process between the rotator cuff and other tendons. We investigated the spontaneous healing process of a surgically created supraspinatus tendon tear in rabbits.Materials and methods A transverse, full-thickness tear of the supraspinatus tendon was created and its healing examined.Results A tear of 12 mm was not repaired within 3 weeks. With a tear of 5 mm, reparative tissue gradually encroached into the defect from the bursal side, and the tear united from the bursal side to the articular side by 12 weeks. The healing rates (width of reparative tissue/width of the tendon×100%) were 32.2%, 52.4%, 58.0%, 88.9%, and 93.8% at 1, 2, 3, 6, and 12 weeks, respectively. The reparative tissue had continuity to the epitenon of the bursal side. Immunohistochemical study showed that at week 1, type III collagen was detected in the reparative tissue and the cutting ends, and the expression gradually decreased. On the other hand, the expression of type I collagen in the reparative tissue was weak at week 1 and increased until week 3. PCNA-positive cells were observed in the reparative tissue.Conclusion These results show that the origin of the reparative tissue is the epitenon, and from the bursal side rather than the articular side. This model is very useful for the investigation of the remodeling process of an acute rotator cuff tear.     

Anatomic study of the tendinous insertion lamina of the temporalis muscle

Lengthening temporalis myoplasty is indicated in long-standing and congenital facial paralysis. Its principle is the transfer of the coronoid tendinous insertions onto the lip and the nasolabial fold. Knowledge of the anatomy of this strong and wide tendon is necessary for successful use of its anatomic advantages. A study on 10 cadavers (20 temporalis muscles) confirmed the surgical anatomy found during lengthening temporalis myoplasty procedures: the strong tendon, when freed from the coronoid process, is 4–6 cm wide.     

锁式肌腱缝合的生物力学研究

目的本实验通过比较Strickland、Augmented Becker、Savage及Tang法四种锁式缝合的生物力学特性,以期指导临床肌腱修复.方法将40根新鲜成年猪后蹄Ⅱ区屈肌腱随机分成4组,分别用Strickland、Augmented Becker、Savage及Tang法进行修复.用材料力学测定仪测定2-mm间隙形成负荷、最大负荷、弹性模量及断裂功耗,同时记录中心缝合的操作时间.结果Tang法的2-mm间隙形成负荷、最大负荷、断裂功耗与Savage法相近,弹性模量为各组中最高,中心缝合的操作时间明显短于Augmented Becker及Savage法.结论Tang法能提供较大的抗张强度、有效抵御间隙形成、操作简便,有利于肌腱早期活动.     

锁式肌腱缝合的生物力学研究

目的本实验通过比较Strickland、augmented Becker、Savage及Tang法四种锁式缝合的生物力学特性,以期指导临床肌腱修复.方法将40根新鲜成年猪后蹄Ⅱ区屈肌腱随机分成4组,分别用Strickland、augmented Becker、Savage及Tang法进行修复.用材料力学测定仪测定2-mm间隙形成负荷、最大负荷、弹性模量及断裂功耗,同时记录中心缝合的操作时间.结果Tang法的2-mm间隙形成负荷、最大负荷、断裂功耗与Savage法相近,弹性模量为各组中最高,中心缝合的操作时间明显短于augmented Becker及Savage法.结论Tang法能提供较大的抗张强度、有效抵御间隙形成、操作简便,有利于肌腱早期活动.     

川芎嗪注射液及丹红注射液联合可吸收生物膜预防肌腱粘连的临床研究

目的探讨川芎嗪注射液及丹红注射液联合可吸收生物膜预防肌腱粘连的临床效果,以供参考。方法将该院2011年3月—2013年2月收治的单指屈指肌腱断裂患者110例纳入该研究,根据随机原则分组。对照组接受生物膜修复肌腱,实验组同时辅以川芎嗪注射液及丹红注射液联合治疗。对比两组在手部肌腱总主动活动度方面的差异性。结果对照组患者手部肌腱总主动活动度优良率为76.36%;观察组患者手部肌腱总主动活动度优良率为96.36%。与对照组对比,该院发现实验组手部肌腱总主动活动度优良率明显较高,组间差异有统计学意义（P〈0.05）。结论川芎嗪注射液及丹红注射液联合可吸收生物膜可有效预防肌腱粘连,促进手部肌腱功能恢复,是一种良好的联合治疗方案。