Achilles tendinopathy is a prevalent, highly debilitating condition. It is believed to result from repetitive overuse, which creates micro-damage tendon, and initiates a catabolic cell response. The aetiology of tendinopathy remains poorly understood, therefore appropriate treatment remains unclear. Current data support the use of shock wave therapy and eccentric exercise as some of the more effective treatment options for tendinopathy. Studies have shown that these treatments generate perturbations within tendon at a frequency of approximately 8-12Hz. Consequently, it is hypothesised that 10Hz loading initiates increased anabolic tenocyte behaviour promoting tendon repair. The primary aim of this thesis is to investigate the effects of 10Hz perturbations on tenocyte metabolism, comparing tenocyte gene expression in response to a 10Hz and 1Hz loading profile. A variety of in vitro models for mechanically stimulating cells were explored, comparing tissue explants with isolated cells on a 2D or within a 3D collagen gel. The mechanical environment of each model was investigated, in addition to cell viability and gene stabilisation following strain, as needed for future cell studies. 3D collagen gels arose as the most suitable model. Human tenocytes from healthy semitendinosus and tendinopathic Achilles tendons were seeded into 3D collagen gels and subjected to cyclic strain at 10Hz and 1Hz to establish cell response. Tenocyte gene expression was characterised using qRT-PCR. Healthy tenocytes showed increased expression of all analysed genes in response to loading. Furthermore, the increase was significantly larger in the 10Hz loading group. Tendinopathic tenocytes showed a more varied response, possibly indicative of an early healing response. Nevertheless, the response to 10Hz loading was consistently greater than seen with 1Hz loading. Analysis of the signalling pathways involved suggested that the IL1 signalling pathway may be involved in the strain response reported. This study has demonstrated for the first time that loading at a frequency of 10Hz may enhance metabolic response in healthy tenocytes.

Tendons transfer forces from muscle to bone and allow the locomotion of the body. However, tendons, especially for tendons in the hand, get lacerated commonly in different injuries and the healing of tendon within the narrow channel in the hand will normally lead to tendon adhesion and sacrificed tendon mechanics. Researches have been focused on addressing tendon adhesion prevention but neglecting healed tendon mechanics. This thesis discusses the principles and challenges in the design of biomaterials regarding flexor tendon repair with advanced polymer chemistry and materials science. A rational platform, not only focusing on the prevention of tendon adhesion, but devoting more efforts on final healed properties of tendons via implementing glycopolymer-based materials to guide tendon cells attachment, was designed, fabricated and characterized. Controlled ring opening polymerizations and atom transfer radical polymerizations were combined for the synthesis of miktoarm well-defined block copolymers. Para-fluorine click reactions were then implemented to afford glycopolymers with glucose units. Obtained copolymers were transformed into 3D membranes constituting a porous fibrous structure utilizing electrospinning. The aligned structure was then fabricated to optimize the mechanics of these materials for practical application as well as reconstruct normal tendon physiological structure. Lastly, the toxicity, cell affinity and cell activity of obtained materials were evaluated in vitro employing tendon cells as a cell line to confirm the suitability of obtained platforms for flexor tendon repair.

Fibrotic diseases account for an estimated 45% of the total number of deaths in the developed world (Wynn 2007). Tendons are an excellent model for studying the dysregulated response which leads to fibrosis, as tendons have an organized, parallel matrix, in which tissue defects could easily be distinguished. Wong et al. (2006b) demonstrated the presence of a bell-shaped region around sutures in tendons that was devoid of cells in histological sections. The mechanisms of the formation of this acellular zone, that was also noted in cornea and cartilage (Matsuda et al. 1999; Hunziker and Stähli 2008), were unknown. It was hypothesized that the acellular zone was formed by cell death and that suturing caused alterations to the extracellular matrix of sutured regions of tendon, which made the acellular zone refractory to cellular re-population. The acellular zone was tracked in sutured tendons for up to a year to determine the temporal properties of the acellular zone. Electron microscopic and time lapse studies were carried out to determine if the acellular zone formed by cell migration or cell death. Microarray analysis was conduced to confirm this and to reveal potential molecular targets for future studies. The extracellular matrix of sutured tendons was studied by electron, atomic, scanning and polarized light microscopy and mechanical measurements were obtained using nanoindentation. It was concluded that the acellular zone formed within 24 hours and persisted for up to a year. Tension and size of the suture's grasp were also shown to be important for acellular zone formation. Cell death was the main effector of acellular zone formation. Microarray analysis showed evidence of upregulation of inflammatory mediators and programmed necrosis pathways. The sutured extracellular matrix was denser, more disorganized and had a lower Young's modulus than unsutured regions of the same tendon. These differences in the properties of the extracellular matrix of sutured tendons may be the cause of the persistence of the acellular zone.

Flexor tendon repair of the hand and rehabilitation are frequently discussed between hand surgeons and therapists. This is mainly due to the poor outcomes commonly achieved after this type of surgery. There are many patients in public hospitals in South Africa who require flexor tendon repair surgery. They are regularly sent to therapists for rehabilitation, where the early passive motion protocol is commonly implemented. Although the early active motion protocol has yielded improved results globally, there is limited evidence on the comparison of the outcomes of these two protocols in the South African context. The aim of the study was to compare the outcomes of an early active motion protocol to the outcomes of an early passive motion protocol in patients with zone II to IV flexor tendon repairs of the hand, attending rehabilitation at Chris Hani Baragwanath Academic Hospital. The study was a quantitative single-blinded comparative controlled trial. Forty-six patients who sustained a zone II-IV flexor tendon injury were recruited for the study and equally distributed between the two groups (early active motion and early passive motion). Out of these participants, 11 did not return for the initial assessment at four weeks post-surgery and were therefore excluded. There were 19 participants in the early active motion group and 16 participants in the early passive motion group. Results were collected and classified at 4, 8 and 12 weeks post-surgery. Data collection took place from December 2014 to January 2016 in the Chris Hani Baragwanath Academic Hospital Hand Unit. At 12 weeks post-surgery, the total active motion, fingertip to table, and distal palmar crease measurements were similar between the two groups. Tendon rupture occurred in 8.57% (n=3, early active motion = 5.71%, early passive motion = 2.86%) of patients. This study found that there was no difference in outcomes between the two groups. Therefore, either protocol could be implemented in South African public hospitals. However, since the early active motion protocol takes less time to implement, this protocol is recommended. A study with a greater magnitude would be necessary to determine a significant comparison between the two groups; however, this is challenging due to poor patient compliance. / Dissertation (MOccupational Therapy)--University of Pretoria, 2017. / Occupational Therapy / MOccupational Therapy / Unrestricted

No description available.

Although rare, distal biceps tears are common in middle-aged men in their 4th and 5th decades of life. The evidence surrounding prognosis, complications and rehabilitation interventions for distal biceps ruptures are of poor quality and therefore, many questions remain to be answered. This thesis includes four manuscripts describing studies that aim to improve our understanding of the rehabilitation of surgical and non-surgical management of distal biceps tendon rupture, prognostic factors associated with surgical repair and the outcomes for non-surgical management. The first manuscript is a scoping review of rehabilitation procedures described in the literature for the management of distal biceps ruptures. Overall, rehabilitation descriptions for distal biceps ruptures are poor for both post-surgical and non-surgical management. The findings suggest heterogeneity, both on the reporting and the content of rehabilitation delivered as a stand-alone intervention or post-operatively. The second manuscript is a cross-sectional study evaluating potential factors associated with reduced function post double incision surgical repair. The findings suggest that having a smoking history and weaker biceps flexion strength are associated with a poor prognosis and accounted for 50.4% of the variability in functional scores. These findings support existing studies that indicate a smoking history is associated with less favourable pain, function and disability outcomes follow distal biceps repair. The third manuscript is a prospective study evaluating prognostic factors associated with reduced function for those undergoing double incision surgical repair. These findings suggest that the majority of persons undergoing a distal biceps repair using a two-incision approach have minimal complications and good functional outcomes. In addition, having surgery on the non-dominant hand and having a weaker grip strength at baseline accounted for 43.4% of the variability of functional scores. The fourth manuscript describes two cases of non-surgical management of a complete distal biceps rupture. Despite the common belief that surgical repair for biceps rupture results in superior elbow flexion and supination strength, these cases demonstrated that full recover of strength and function is possible through rehabilitation alone. This study contributes to the evidence-base by questioning the need for surgical repair for all cases of distal biceps ruptures. / Dissertation / Doctor of Philosophy (PhD) / The biceps tendon is prone to rupture where it inserts into the elbow. While not a common injury, it does occur more often in middle aged men following a forceful movement. Most of the research regarding the prognosis and management of distal biceps ruptures is of poor quality and imprecise due to small sample sizes. This thesis examined management in a set of studies. A scoping review indicated that rehabilitation descriptions for distal bicep ruptures were of very poor quality for both surgical and non-surgical management for this condition. A cross-sectional analysis of 60 patients revealed that having a smoking history and weaker flexion strength was associated with poor outcomes after distal biceps repairs. A prospective cohort study of 34 patients found that having surgery on the non-dominant arm and weaker grip strength was associated with poor outcomes 6-12 months after surgical repair. Given the excellent outcomes after surgery and presumption of the need for surgery as standard practice, there has been little attention to the role of conservative management. We evaluated two cases where patients refused surgery and were able to recover full strength and functional abilities using a comprehensive rehabilitation program. This thesis confirms that excellent outcomes occur after this injury and raises the need for future trials comparing surgery and rehabilitation as treatment options. The fact that this injury often occurs in healthy men may partially explain the excellent outcomes with surgery or rehabilitation.

Abstract The purposes of the present research were to compare the outcome after Achilles tendon rupture repair in two postoperative regimens, to compare Achilles tendon elongation in two postoperative treatment methods, to compare the effects of two postoperative methods on motor performance aspects such as simple reaction time, choice reaction time, speed of movement, foot tapping speed and coordination, to test the mechanical properties of the recently developed poly-L/D-lactide (PLDLA) sutures and Maxon® sutures when implanted in the Achilles tendons of rabbits, and to study the histological tissue reactions and biodegradation of these sutures under the same conditions. Isokinetic calf muscle strength scores at the last control check-up were excellent in 56% of the patients in the early motion group, good in 32%, fair in 8%, and poor in 4%, whereas the scores in the cast group were excellent in 29% of cases, good in 50% and fair in 21%. The ankle performance scores were excellent or good in 88% of the patients in the early motion group, fair in 4% and poor in 8%, whereas the scores in the cast group were excellent or good in 92% of cases and fair in 8%. No significant differences were seen between the two groups at 3 months and at the last control checkups with regard to pain, stiffness, subjective calf muscle weakness, footwear restrictions, range of ankle motion, isokinetic calf muscle strength or overall outcome. The complications included 1 re-rupture in the early motion group and 1 deep infection and 2 re-ruptures in the cast group. AT elongation occurred in both groups, but was somewhat less marked in the early motion group. The AT elongation curves rose at first and then fell slowly in both groups. The patients who had less AT elongation achieved a better clinical outcome. AT elongation did not correlate significantly with age, body mass index or isokinetic peak torques. The recovery of motor performance functions such as simple reaction time, choice reaction time, speed of movement, foot tapping speed and coordination did not depend on the two postoperative regimens. The motor functions of the operated leg had obviously recovered to the level of the non-operated leg 12 weeks after the operation. Sutures made of PLDLA were used successfully for Achilles tendon repair in rabbits. There was no significant difference between the in vitro and in vivo tensile strength retention of the sutures. By comparison with Maxon®, PLDLA was found to have a lower initial tensile strength but more prolonged strength retention. The breaking strength values of the Achilles tendons repaired with sutures of these types were not significantly different at 6 weeks. Intratendinous PLDLA sutures formed a thinner fibrous capsule during the 12-week follow-up period than did Maxon® sutures of the same diameter. The suture materials had not been totally absorbed by 12 weeks.

Abstract Early motion is crucial for tendon healing and functional results after flexor tendon repair in the fingers. Motion, however, causes stress in the repair site, which can result in failure of the repair. A flexor tendon repair is made with fine calibre sutures, which sets exceptional requirements for the suture materials used in flexor tendon repair. Nitinol (nickel-titanium alloy) is a shape memory alloy, which can exist in two temperature-dependent forms, soft martensite and stiff austenite. It is possible to fabricate a nitinol wire that is soft and pliable, yet has high tensile strength. It also has excellent biocompatibility. Therefore, it is a potential candidate flexor tendon repair suture material. This study evaluates biomechanical aspects of martensite nitinol wire as a flexor tendon repair suture material. The study hypothesis was that nitinol wire improves the strength of the repairs compared with the repairs made with conventional suture materials. It was found that nitinol core repairs and circumferential repairs performed significantly better when compared with repairs made with commonly used braided polyester and polypropylene of equal calibre. To further optimise the performance of the nitinol wire in tendon surgery, two experimental models were developed to study the suture-tendon interface. The aim was to prevent pull-out of the suture loop so that surgeons could have full advantage of the tensile strength of the nitinol suture. First, it was tested whether it is possible to improve the suture’s ability to grip the tendon tissue by changing the suture type from monofilament to multifilament. Multifilament suture loops reached higher pull-out strength when compared with round monofilament loops when a locking loop was used. Subsequently, the grip of four different previously reported core repair loops was tested. Based on their failure mechanism, two novel loops were developed. The novel loops demonstrated superior ability to grip the tendon. The novel loops can be useful with high tensile strength suture materials and in repairs, which are prone to suture pull-out. / Tiivistelmä Varhainen korjauksen jälkeinen aktiivinen kuntoutus on osoittautunut hyödylliseksi jänteen paranemiselle. Varhainen liike altistaa korjauksen kuormitukselle, joka voi johtaa korjauksen pettämiseen. Korjaukset tehdään ohuilla langoilla. Tämä asettaa erityisiä vaatimuksia jännekorjauksessa käytettävälle ommelainemateriaalille. Nikkeli-titaani (nitinoli) on nk. muistimetalli. Sillä on kaksi lämpötilariippuvaista muotoa: pehmeä martensiitti ja jäykkä austeniitti. Nitinolista voidaan valmistaa ohutta pehmeää ja taipuisaa lankaa, jonka vetolujuus on suuri. Nitinolin siedettävyys jännekudoksessa on todettu hyväksi, minkä vuoksi se on lupaava materiaali käytettäväksi jännekorjauksissa. Tässä tutkimuksessa kokeiltiin martensiittisen nitinolilangan käyttöä jänteen ydinompeleena ja pintaompeleena. Olettamuksena oli, että nitinolilangalla saadaan kestävämpiä korjauksia kuin nykyään käytössä olevilla langoilla. Tulosten mukaan nitinolilangalla tehdyt korjaukset olivat kestävämpiä, kun niitä verrattiin saman paksuiseen punottuun polyesteriin ja polypropyleeniin. Lisäksi kehitimme kaksi mallia, joiden tarkoituksena oli parantaa nitinolilankasilmukan pitoa jännekudoksesta. Tarkoituksena oli löytää keinoja, joilla langan otetta jännekudoksesta voidaan parantaa ja langan hyvät vetolujuusominaisuudet pääsevät oikeuksiinsa. Ensin muutimme langan muotoa perinteisestä yksisäikeisestä pyöreästä monisäikeiseen muotoon. Monisäikeisen langan läpileikkausvoima oli huomattavasti suurempi kuin yksisäikeisen pyöreän langan. Ero oli havaittavissa vain, kun käytettiin lukitsevaa silmukkaa. Tämän jälkeen testasimme neljän perinteisesti käytetyn korjaustekniikan silmukan pitokykyä ja tulosten perusteella kehitimme kaksi uutta silmukkaa. Työssä kehitetyt silmukat pitivät kiinni jänteestä huomattavasti paremmin kuin perinteiset silmukat. Työssä kehitetyillä silmukoilla voidaan optimoida vahvojen ommelainemateriaalien suorituskyky jännekirurgiassa.

Made available in DSpace on 2016-06-02T20:19:05Z (GMT). No. of bitstreams: 1 1361.pdf: 7031010 bytes, checksum: e59579f600a182ade6d5f0cd26523978 (MD5) Previous issue date: 2007-02-27 / Universidade Federal de Sao Carlos / There is a rapid increase in the size of the elderly population due to a complex interaction of medical and epidemiological factors. Also, there is a parallel increase in morbidity associated with age-related delayed tendinopathy healing, and treatment of such acute and chronic condition costs the Health Services over 1 Billion dollars per year. Despite the obvious clinical impact, the basic cellular and molecular mechanisms underlying impaired human tendon healing are largely unknown. However, recent reports have showed the action mechanism of low level laser therapy (LLLT) in producing accelerated tendon healing, but the real effects of this therapy associated with aging effects are not yet known. This study evaluated the effects of the LLLT on repair process of rat calcaneal tendon in two different ages. Eighty male Wistar rats were divided in 2 experimental groups with 40 rats at each one: young group (4 weeks old, body mass = 111.3±34,3g) and mature adult group (27 weeks old, body mass = 385.4±34,3g). The young group was subdivided in subgroup Y3J (12 session, total energy = 101.7mJ, laser 685nm, 5.4W/cm2, 3J/cm2), subgroup Y10J (12 session, total energy = 339.6mJ, laser 685nm, 5.4W/cm2, 10J/cm2); subgroup YPL (placebo treatment) and subgroup YCL (no treatment). The mature adult group was subdivided in subgroup A3J (12 session, total energy = 101.7mJ, laser 685nm, 5.4W/cm2, 3J/cm2), subgroup A10J (12 session, total energy = 339.6mJ, laser 685nm, 5.4W/cm2, 10J/cm2); subgroup APL (placebo treatment) and subgroup ACL (no treatment). All animals had the medial region of right calcaneal tendon totally tenotomized. They were sacrified on the 13th post-operate day and their tendons were surgically removed for a quantitative and qualitative analysis The Atomic Force Microscopy analysis showed better organization quality (alignment, thickness and aggregation) of collagen bounds in mature irradiated groups. However, it was found differences (p < 0.05) in thickness of collagen bundles (TCBs) for several intersections among subgroups. The subgroup A10J presented greatest TCBs (5.69±0.69), and the ACL subgroup presented smallest TCBs (4.51±0.6) in the mature group. The dimensional data showed higher differences in the irradiated subgroup in mature group when compared to the same subgroup in young group. Histological analysis showed increase (p < 0.05) in the number of capillar vessels and fibroblast cell proliferation after LLLT in both young and mature groups, however the higher modulation was observed in the mature group. Minor influence of laser radiation in the young group may be justified by divergence on chemistry, physics and metabolic age-related. Maybe the accumulated oxidative stress resulting from a gradual shift in the redox status of tissues should be a key mechanism underlying the aging process and the higher laser effect noted in the mature group. Age should be considerated an important parameter to LLLT. / O envelhecimento biológico é uma das principais causas para a predisposição do tendão aos processos degenerativos, patológicos e retardo da reparação tecidual.Várias modalidades terapêuticas são utilizadas para promover a aceleração e melhora do reparo tendíneo, dentre elas a terapia laser de baixa intensidade (LLLT). Porém são pouco conhecidos os reais efeitos desta terapia quando se associa um fator potencialmente decisivo na resposta celular como o envelhecimento. Este estudo avaliou através de técnicas de microscopia de luz comum e de força atômica os efeitos da LLLT, aplicada na reparação do tendão calcanear em duas fases maturacionais. Um grupo de ratos jovens (4 semanas de idade, n = 40, massa = 111,3±8,3g), subdividido aleatoriamente em 4 subgrupos contendo cada um 10 animais: J3J (dose 3J/cm2, energia total = 101,7mJ), J10J (10J/cm2, energia total = 339,6mJ), placebo - JPL (dose 0J/cm2), controle - JCL (nenhum tratamento); e um grupo adulto (27 semanas de idade, n = 40, massa = 385,4±34,3g), subdividido aleatoriamente em 4 subgrupos: A3J (dose 3J/cm2, energia total = 101,7mJ), A10J (dose 10J/cm2, energia total = 339,6mJ), placebo - APL (dose 0J/cm2), controle - ACL (sem tratamento). Todos os animais foram submetidos ao procedimento de tenotomia radical do tendão direito, entre a inserção calcanear e a transição miotendínea, sem posterior tenorrafia. O laser utilizado (685nm, 5,4W/cm2) foi aplicado em 12 sessões, uma vez ao dia, em um único ponto sobre a região da lesão. No 13º dia pós-operatório os animais foram sacrificados e seus tendões removidos, processados e analisados qualitativa e quantitativamente, por meio de microscopia de força atômica (MFA) e análise histológica por morfometria. A análise dos dados mostrou significativa alteração (p< 0,05) da resposta do tecido à irradiação laser, tanto de forma idade-dependente como dose-dependente, sendo que, os resultados demonstram maior relevância para o grupo adulto que para o jovem. Comparativamente, o grupo adulto apresentou qualitativamente maior resposta biológica na agregação, organização, alinhamento do colágeno. Quantitativamente, o grupo adulto apresentou melhor resposta para a dose de 10J/cm2 principalmente em relação à angiogênese, contagem de fibroblastos e espessura dos feixes de colágeno. Esses resultados possivelmente podem ter uma relação com o maior estresse oxidativo característico ao incremento da idade.

Made available in DSpace on 2016-06-02T20:19:19Z (GMT). No. of bitstreams: 1 DissACBS.pdf: 10545595 bytes, checksum: 079933a164ff065ae11e54e43ae5200a (MD5) Previous issue date: 2004-12-20 / The purpose of this study was to analyze the 660 nm GaAlAs laser effect with 10 mW and 40 mW, during 10 seconds, on angiogenesis process and repair quality after partial lesion of Achilles tendon in rats. It was used 104 male rats, that 96 rats had been submitted to lesion by a falling of 186 g from a height of 20 cm, above the right tendon. These rats had been randomly divided in 3 groups, treated in 3 (n = 32), 5 (n = 32) and 7 (n = 32) days, respectively. Each of these groups was divided again into 4 subgroups, which were submitted to laser with mean output of 10 mW (n = 8) and 40 mW (n = 8), a sham treatment (n = 8), and a group with no treatment (n = 8). The analyzes were made by vessels count that have been previous prepared with nanquim ink and by a semiqualitative analyze of polynuclear cells presence, mononuclear cells presence, collagen organization and neovascularization. A fourth group with 8 animals was established as control, without lesion and used as reference for qualitative analyze. The comparison of the groups made evident that the animals submitted to laser showed more vessels number than the control groups (p<0,05) and the 40 mW subgroup showed better vascularization than the others after 3 days of irradiation. (p<0,01). The semiqualitative analyze showed statistical difference (p<0,05) when considering collagen organization and neovascularization in the comparison between the 10 mW, 40 mW and control. Qualitatively, the groups treated with laser showed better repair aspect. The results permit us to conclude that Low Level Laser Therapy with 660 nm promoted an increase of the blood vessels number and better repair quality and the mean output of 40 mW had begun the neovascularization precocious, showing significant difference after 3 days of application. / A proposta desse estudo foi analisar os efeitos do laser AsGaAl, de 660 nm, com 10 mW e 40 mW de potência de saída, aplicado durante 10 segundos, no processo de angiogênese e qualidade de reparo após lesão parcial do tendão calcâneo de ratos. Foram utilizados 104 ratos machos, sendo que 96 foram submetidos à lesão com a queda de um peso de 186 gramas na altura de 20 cm sobre o tendão direito. Estes foram divididos aleatoriamente em 3 grupos, tratados em 3 (n = 32), 5 (n = 32) e 7 (n = 32) dias, respectivamente. Cada um desses grupos foi ainda dividido em 4 subgrupos, submetidos ao laser com potência de saída de 10 mW (n = 8) e 40 mW (n = 8), grupo placebo (n = 8) e grupo sem tratamento (n = 8). As análises foram feitas através da contagem dos vasos que foram previamente corados com tinta nanquim e por meio de uma análise semiqualitativa da presença de células polimorfonucleares, mononucleares, organização de colágeno e neovascularização. Um quarto grupo com 8 animais foi estabelecido como controle padrão, sem lesão que foi utilizado como referência para a análise qualitativa. A comparação dos grupos evidenciou que os animais irradiados mostraram maior número de vasos do que os grupos controle (p<0,05) e o subgrupo de 40 mW apresentou melhor vascularização que os demais após 3 dias de irradiação (p<0,01). A análise semiqualitativa evidenciou diferença estatística (p<0,05) quando foi considerada a organização de colágeno e a neovascularização na comparação entre os grupos 10 mW e 40 mW com os controle. Qualitativamente os grupos tratados com laser apresentaram melhor aspecto do reparo. Os resultados nos permitem concluir que a terapia laser de baixa intensidade, com comprimento de onda de 660 nm promoveu aumento na neovascularização e melhora na qualidade de reparo e a potência de saída de 40 mW iniciou a neovascularização precocemente, mostrando diferença significativa após 3 dias de aplicação.