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1.
Equine Vet J ; 53(1): 149-156, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32386069

RESUMO

BACKGROUND: Rehabilitation of tendon injuries in horses often involves cryotherapy to reduce inflammation and occasionally tissue heating to increase collagen extensibility. The application of alternating cold and hot (ie contrast therapy) is widely used in human physical therapy; however, its utility in equine rehabilitation is largely unknown. OBJECTIVES: The objectives of this study were to (a) assess if the equipment could achieve therapeutic tissue temperatures (<15 and >40°C) at different tissue depths relative to the digital flexor tendons and (b) evaluate the time-temperature profiles during serial heating and cooling cycles using a contrast therapy device. STUDY DESIGN: In vivo experiment. METHODS: In 4 adult horses with normal forelimb digital flexor tendons, fine-wire temperature probes were placed superficially on the skin and implanted subcutaneously, deep to the superficial digital flexor tendon (SDFT) and deep to the deep digital flexor tendon (DDFT). Temperatures were recorded over three complete thermal (hot-cold) cycles. Minimum and maximum temperatures were recorded and the rate of temperature changes and the areas underneath the time-temperature curves (ie thermal load) were calculated. RESULTS: Minimum and maximum tissue temperatures (°C) included: superficial skin [12.6 ± 1.0; 42.4 ± 2.4], subcutaneous tissues [14.1 ± 0.8; 42.3 ± 2.2], deep to the SDFT [15.6 ± 0.8; 41.7 ± 2.6] and deep to DDFT [25.1 ± 2.0; 38.0 ± 3.5]. An initial rapid rate of tissue temperature change between 3.2 and 4.3°C/min occurred within tissues to the depth of the DDFT. Tissue thermal loads during heating ranged from 255 to 607°C*second and from 309 to 780°C*second during tissue cooling, with the lower values noted deep to the DDFT. MAIN LIMITATIONS: Unknown clinical efficacy in diseased tissues. CONCLUSIONS: The applied contrast therapy was consistently able to induce cooling and heating of tissues to the depth of the DDFT.


Assuntos
Doenças dos Cavalos , Traumatismos dos Tendões , Animais , Extremidades , Membro Anterior , Calefação , Doenças dos Cavalos/terapia , Cavalos , Traumatismos dos Tendões/veterinária , Tendões
2.
Nat Commun ; 11(1): 6375, 2020 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-33311457

RESUMO

Syncytial skeletal muscle cells contain hundreds of nuclei in a shared cytoplasm. We investigated nuclear heterogeneity and transcriptional dynamics in the uninjured and regenerating muscle using single-nucleus RNA-sequencing (snRNAseq) of isolated nuclei from muscle fibers. This revealed distinct nuclear subtypes unrelated to fiber type diversity, previously unknown subtypes as well as the expected ones at the neuromuscular and myotendinous junctions. In fibers of the Mdx dystrophy mouse model, distinct subtypes emerged, among them nuclei expressing a repair signature that were also abundant in the muscle of dystrophy patients, and a nuclear population associated with necrotic fibers. Finally, modifications of our approach revealed the compartmentalization in the rare and specialized muscle spindle. Our data identifies nuclear compartments of the myofiber and defines a molecular roadmap for their functional analyses; the data can be freely explored on the MyoExplorer server ( https://shiny.mdc-berlin.de/MyoExplorer/ ).


Assuntos
Núcleo Celular/genética , Núcleo Celular/metabolismo , Músculo Esquelético/crescimento & desenvolvimento , Músculo Esquelético/metabolismo , Transcriptoma , Animais , Linhagem Celular , Citoplasma , Modelos Animais de Doenças , Regulação da Expressão Gênica no Desenvolvimento , Heterogeneidade Genética , Humanos , Camundongos , Camundongos Endogâmicos mdx , Fibras Musculares Esqueléticas , Músculo Esquelético/citologia , Distrofias Musculares/genética , Distrofias Musculares/metabolismo , RNA-Seq , Regeneração , Tendões
3.
Nat Commun ; 11(1): 6374, 2020 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-33311464

RESUMO

While the majority of cells contain a single nucleus, cell types such as trophoblasts, osteoclasts, and skeletal myofibers require multinucleation. One advantage of multinucleation can be the assignment of distinct functions to different nuclei, but comprehensive interrogation of transcriptional heterogeneity within multinucleated tissues has been challenging due to the presence of a shared cytoplasm. Here, we utilized single-nucleus RNA-sequencing (snRNA-seq) to determine the extent of transcriptional diversity within multinucleated skeletal myofibers. Nuclei from mouse skeletal muscle were profiled across the lifespan, which revealed the presence of distinct myonuclear populations emerging in postnatal development as well as aging muscle. Our datasets also provided a platform for discovery of genes associated with rare specialized regions of the muscle cell, including markers of the myotendinous junction and functionally validated factors expressed at the neuromuscular junction. These findings reveal that myonuclei within syncytial muscle fibers possess distinct transcriptional profiles that regulate muscle biology.


Assuntos
Núcleo Celular/genética , Heterogeneidade Genética , Fibras Musculares Esqueléticas/metabolismo , RNA-Seq/métodos , Animais , Núcleo Celular/metabolismo , Citoplasma , Genômica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Músculo Esquelético/crescimento & desenvolvimento , Músculo Esquelético/metabolismo , Junção Neuromuscular , Análise de Sequência de RNA , Tendões
4.
Arthroscopy ; 36(12): 2982-2983, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33276886

RESUMO

Tenodesis of the long head of the biceps tendon has long been a source of dialogue, discussion, debate, and dogma. In general, the shoulder literature has been exhaustive regarding various biceps tenodesis techniques and outcomes, and studies have shown positive clinical outcomes of tenodesis, regardless of location, along the proximal humerus. Fewer studies have evaluated the outcomes of revision tenodesis; however, those that have looked at this have generally found that a revision to a subpectoral tenodesis site is usually quite successful.


Assuntos
Tenodese , Braço/cirurgia , Humanos , Músculo Esquelético/cirurgia , Ombro/cirurgia , Tendões/cirurgia
5.
PLoS One ; 15(11): e0242324, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33186411

RESUMO

The aim of the current study was to investigate the effect of a single session of prolonged tendon vibration combined with low submaximal isometric contraction on maximal motor performance. Thirty-two young sedentary adults were assigned into two groups that differed based on the knee angle tested: 90° or 150° (180° = full knee extension). Participants performed two fatigue-inducing exercise protocols: one with three 10 min submaximal (10% of maximal voluntary contraction) knee extensor contractions and patellar tendon vibration (80 Hz) another with submaximal knee extensor contractions only. Before and after each fatigue protocol, maximal voluntary isometric contractions (MVC), voluntary activation level (assessed by the twitch interpolation technique), peak-to-peak amplitude of maximum compound action potentials of vastus medialis and vastus lateralis (assessed by electromyography with the use of electrical nerve stimulation), peak twitch amplitude and peak doublet force were measured. The knee extensor fatigue was significantly (P<0.05) greater in the 90° knee angle group (-20.6% MVC force, P<0.05) than the 150° knee angle group (-8.3% MVC force, P = 0.062). Both peripheral and central alterations could explain the reduction in MVC force at 90° knee angle. However, tendon vibration added to isometric contraction did not exacerbate the reduction in MVC force. These results clearly demonstrate that acute infrapatellar tendon vibration using a commercial apparatus operating at optimal conditions (i.e. contracted and stretched muscle) does not appear to induce knee extensor neuromuscular fatigue in young sedentary subjects.


Assuntos
Contração Isométrica , Joelho/fisiologia , Fenômenos Mecânicos , Tendões/fisiologia , Vibração , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Fadiga Muscular , Adulto Jovem
6.
Am J Sports Med ; 48(13): 3347-3358, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33136454

RESUMO

BACKGROUND: Efforts are being made to treat rotator cuff tears (RCTs) that exhibit poor healing and high retear rates. Tendon-to-bone healing using mesenchymal stem cells is being explored, but research is needed to establish effective delivery options. PURPOSE: To evaluate the effects of an adipose-derived stem cell (ADSC) sheet on mesenchymal stem cell delivery for tendon-to-bone healing of a chronic RCT in rats and to demonstrate that ADSC sheets enhance tendon-to-bone healing. STUDY DESIGN: Controlled laboratory study. METHODS: Mesenchymal stem cells were obtained from rat adipose tissue, and a cell sheet was prepared using a temperature-responsive dish. To evaluate the efficacy of stem cells produced in a sheet for the lesion, the experiment was conducted with 3 groups: repair group, cell sheet transplantation after repair group, and cell sheet-only group. Histological, biomechanical, and micro-computed tomography (micro-CT) results were compared among the groups. RESULTS: Hematoxylin and eosin staining for histomorphological analysis revealed that the cell sheet transplantation after repair group (5.75 ± 0.95) showed statistically significant higher scores than the repair (2.75 ± 0.50) and cell sheet-only (3.25 ± 0.50) groups (P < .001). On safranin O staining, the cell sheet transplantation after repair group (0.51 ± 0.04 mm2) had a larger fibrocartilage area than the repair (0.31 ± 0.06 mm2) and cell sheet-only (0.32 ± 0.03 mm2) groups (P = .001). On micro-CT, bone volume/total volume values were significantly higher in the cell sheet transplantation after repair group (23.98% ± 1.75%) than in the other groups (P < .039); there was no significant difference in the other values. On the biomechanical test, the cell sheet transplantation after repair group (4 weeks after repair) showed significantly higher results than the other groups (P < .005). CONCLUSION: Our study shows that engineered stem cells are a clinically feasible stem cell delivery tool for rotator cuff repair. CLINICAL RELEVANCE: This laboratory study provides evidence that ADSCs are effective in repairing RCTs, which are common sports injuries.


Assuntos
Lesões do Manguito Rotador , Engenharia Tecidual , Cicatrização , Tecido Adiposo , Animais , Modelos Animais de Doenças , Ratos , Manguito Rotador , Tendões , Microtomografia por Raio-X
7.
PLoS Biol ; 18(11): e3000902, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33201874

RESUMO

Coordinated development of muscles, tendons, and their attachment sites ensures emergence of functional musculoskeletal units that are adapted to diverse anatomical demands among different species. How these different tissues are patterned and functionally assembled during embryogenesis is poorly understood. Here, we investigated the morphogenesis of extraocular muscles (EOMs), an evolutionary conserved cranial muscle group that is crucial for the coordinated movement of the eyeballs and for visual acuity. By means of lineage analysis, we redefined the cellular origins of periocular connective tissues interacting with the EOMs, which do not arise exclusively from neural crest mesenchyme as previously thought. Using 3D imaging approaches, we established an integrative blueprint for the EOM functional unit. By doing so, we identified a developmental time window in which individual EOMs emerge from a unique muscle anlage and establish insertions in the sclera, which sets these muscles apart from classical muscle-to-bone type of insertions. Further, we demonstrate that the eyeballs are a source of diffusible all-trans retinoic acid (ATRA) that allow their targeting by the EOMs in a temporal and dose-dependent manner. Using genetically modified mice and inhibitor treatments, we find that endogenous local variations in the concentration of retinoids contribute to the establishment of tendon condensations and attachment sites that precede the initiation of muscle patterning. Collectively, our results highlight how global and site-specific programs are deployed for the assembly of muscle functional units with precise definition of muscle shapes and topographical wiring of their tendon attachments.


Assuntos
Músculos Oculomotores/embriologia , Músculos Oculomotores/crescimento & desenvolvimento , Tretinoína/metabolismo , Animais , Tecido Conjuntivo/fisiologia , Desenvolvimento Embrionário , Olho , Imageamento Tridimensional/métodos , Camundongos/embriologia , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Morfogênese , Transdução de Sinais , Tendões/fisiologia , Tretinoína/fisiologia
8.
PLoS One ; 15(11): e0242416, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33216756

RESUMO

INTRODUCTION: Illusion of movement induced by tendon vibration is an effective approach for motor and sensory rehabilitation in case of neurological impairments. The aim of our study was to investigate which modality of visual feedback in Virtual Reality (VR) associated with tendon vibration of the wrist could induce the best illusion of movement. METHODS: We included 30 healthy participants in the experiment. Tendon vibration inducing illusion of movement (wrist extension, 100Hz) was applied on their wrist during 3 VR visual conditions (10 times each): a moving virtual hand corresponding to the movement that the participants could feel during the tendon vibration (Moving condition), a static virtual hand (Static condition), or no virtual hand at all (Hidden condition). After each trial, the participants had to quantify the intensity of the illusory movement on a Likert scale, the subjective degree of extension of their wrist and afterwards they answered a questionnaire. RESULTS: There was a significant difference between the 3 visual feedback conditions concerning the Likert scale ranking and the degree of wrist's extension (p<0.001). The Moving condition induced a higher intensity of illusion of movement and a higher sensation of wrist's extension than the Hidden condition (p<0.001 and p<0.001 respectively) than that of the Static condition (p<0.001 and p<0.001 respectively). The Hidden condition also induced a higher intensity of illusion of movement and a higher sensation of wrist's extension than the Static condition (p<0.01 and p<0.01 respectively). The preferred condition to facilitate movement's illusion was the Moving condition (63.3%). CONCLUSIONS: This study demonstrated the importance of carefully selecting a visual feedback to improve the illusion of movement induced by tendon vibration, and the increase of illusion by adding VR visual cues congruent to the illusion of movement. Further work will consist in testing the same hypothesis with stroke patients.


Assuntos
Retroalimentação Sensorial/fisiologia , Ilusões/fisiologia , Movimento/fisiologia , Tendões/fisiologia , Realidade Virtual , Adulto , Idoso , Idoso de 80 Anos ou mais , Sinais (Psicologia) , Voluntários Saudáveis , Humanos , Pessoa de Meia-Idade , Reabilitação do Acidente Vascular Cerebral , Vibração , Adulto Jovem
9.
Medicine (Baltimore) ; 99(46): e22912, 2020 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-33181657

RESUMO

Peroneus longus and peroneus brevis tendon grafts have been frequently used to reconstruct the lateral ankle ligaments. However, there is no literature comparing the effect of the 2 methods. The purpose of this study was to compare the effects of 2 autologous tendon transplants on ankle joint activity.This retrospective study included 100 adult patients with chronic lateral ankle instability (CLAI) who underwent surgery from January 2014 to December 2017. Group A (50 patients): Reconstruction of the lateral ankle ligaments using the anterior half of peroneus longus tendon graft; Group B (50 patients): Using the anterior half of peroneus brevis tendon graft. Outcomes were assessed by comparing pre- and postoperative AOFAS scores, VAS pain scores, and Karlsson scores, and the radiographic assessment included talar tilt and anterior talar translation. A sensitive dynamometer was used before and after surgery to assess inversion, valgus, plantarflexion, and dorsiflexion strength to evaluate changes in muscle strength in the patients feet.Postoperatively, 88 patients were followed up for 12 to 24 months, including 46 cases in group A and 42 in group B. No severe complications were recorded in the 2 groups. There were significant pre- to post-operative differences between the groups. No significant differences were observed in the postoperative scores and muscle strength changes between the groups. However, the number of patients with decreased valgus strength in group B was statistically significant compared with group A.Both methods can improve the stability of the ankle joint, but the peroneus longus tendon has little effect on the postoperative muscle strength of the foot and should be used as the preferred surgical treatment for the treatment of CLAI.


Assuntos
Articulação do Tornozelo/cirurgia , Artroplastia/métodos , Instabilidade Articular/cirurgia , Ligamentos Laterais do Tornozelo/cirurgia , Tendões/transplante , Adulto , Pesquisa Comparativa da Efetividade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
10.
Syst Rev ; 9(1): 264, 2020 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-33220705

RESUMO

BACKGROUND: Flexor tendon injuries most commonly occur following a penetrating injury to the hand or wrist. These are challenging injuries and the standard treatment is surgical repair under general or regional anaesthesia. 'Wide-awake' surgery is an emerging technique in hand surgery where a conscious patient is operated on under local anaesthetic. The vasoconstrictive effect of adrenaline (epinephrine) creates a 'bloodless' operating field and a tourniquet is not required. The potential advantages include intra-operative testing of the repair; removal of the risks of general anaesthesia; reduced costs; no aerosol generation from intubation therefore reduced risk of COVID-19 spread to healthcare professionals. The aim of this study will be to systematically evaluate the evidence to determine if wide-awake surgery is superior to general/regional anaesthetic in adults who undergo flexor tendon repair. METHODS: We designed and registered a study protocol for a systematic review and meta-analysis of comparative and non-comparative studies. The primary outcome will be functional active range of motion. Secondary outcomes will be complications, resource use (operative time) and patient-reported outcome measures. A comprehensive literature search will be conducted (from 1946 to present) in MEDLINE, EMBASE, CINAHL, and Cochrane Library. Grey literature will be identified through Open Grey, dissertation databases and clinical trials registers. All studies on wide-awake surgery for flexor tendon repair will be included. The comparator will be general or regional anaesthesia. No limitations will be imposed on peer review status or language of publication. Two investigators will independently screen all citations, full-text articles and abstract data. Potential conflicts will be resolved through discussion or referral to a third author when necessary. The study methodological quality (or bias) will be appraised using an appropriate tool. If feasible, we will conduct a random effects meta-analysis. DISCUSSION: This systematic review will summarise the best available evidence and definitively establish if function, complications, cost, or patient-reported outcomes are improved when flexor tendons are repaired using wide-awake technique. It will determine if this novel approach is superior to general or regional anaesthesia. This knowledge will help guide hand surgeons by continuing to improve outcomes from flexor tendon injuries. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020182196.


Assuntos
Anestesia Local , Anestésicos Locais , Mãos/cirurgia , Controle de Infecções , Traumatismos dos Tendões/cirurgia , Vigília , Adulto , Anestesia por Condução , Anestesia Geral , /virologia , Epinefrina , Humanos , Metanálise como Assunto , Procedimentos Ortopédicos , Pandemias , Amplitude de Movimento Articular , Projetos de Pesquisa , Revisões Sistemáticas como Assunto , Tendões/cirurgia , Torniquetes , Resultado do Tratamento
11.
Bone Joint J ; 102-B(12): 1608-1617, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33249900

RESUMO

AIMS: The aim of this systematic review and meta-analysis is to evaluate differences in functional outcomes and complications between single- (SI) and double-incision (DI) techniques for the treatment of distal biceps tendon rupture. METHODS: A comprehensive search on PubMed, MEDLINE, Scopus, and Cochrane Central databases was conducted to identify studies reporting comparative results of the SI versus the DI approach. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was used for search strategy. Of 606 titles, 13 studies met the inclusion criteria; methodological quality was assessed with the Newcastle-Ottawa scale. Random- and fixed-effects models were used to find differences in outcomes between the two surgical approaches. The range of motion (ROM) and the Disabilities of the Arm, Shoulder and Hand (DASH) scores, as well as neurological and non-neurological complications, were assessed. RESULTS: A total of 2,622 patients were identified. No significant differences in DASH score were detected between the techniques. The SI approach showed significantly greater ROM in flexion (standardized mean difference (SMD) -0.508; 95% confidence interval (CI) -0.904 to -0.112) and pronation (SMD -0.325, 95% CI -0.637 to -0.012). The DI technique was associated with significantly less risk of lateral antebrachial cutaneous nerve damage (odds ratio (OR) 4.239, 95% CI 2.171 to 8.278), but no differences were found for other nerves evaluated. The SI group showed significantly fewer events of heterotopic ossification (OR 0.430, 95% CI 0.226 to 0.816) and a lower reoperation rate (OR 0.503, 95% CI 0.317 to 0.798). CONCLUSION: No significant differences in functional scores can be expected between the SI and DI approaches after distal biceps tendon repair. The SI approach showed greater flexion and pronation ROM and a lower risk of heterotopic ossification and reoperation. The DI approach was favourable in terms of lower risk of neurological complications. Cite this article: Bone Joint J 2020;102-B(12):1608-1617.


Assuntos
Traumatismos do Braço/cirurgia , Traumatismos dos Tendões/cirurgia , Tendões/cirurgia , Humanos , Músculo Esquelético/lesões , Músculo Esquelético/cirurgia , Procedimentos Ortopédicos/métodos , Ferida Cirúrgica
12.
Acta Ortop Mex ; 34(2): 107-111, 2020.
Artigo em Espanhol | MEDLINE | ID: mdl-33244911

RESUMO

INTRODUCTION: Since William Clancy (1979) and Richard Ferkel (1997) publications, the technique of peroneal groove deepening in patients with chronic dislocation, has been used with very satisfactory results and few complications. The aim of the present study is to describe a new minimally invasive technique of peroneal groove deepening with burs and specific percutaneous surgery instrumentation and without fibula osteotomy; and to evaluate the clinical and imaging results, in 5 patients operated with this technique. MATERIAL AND METHODS: A retrospective study of 5 patients with clinical and imaging diagnosis of chronic dislocation of peroneal tendons. They were treated with minimally invasive technique. This technique was described in this paper. Results were evaluated by preoperative and postoperative AOFAS score and by images (dynamic ultrasound, TAC and RMN). RESULTS: None of the treated patients presented dislocation recurrence or pain at the time of evaluation. The AOFAS score improved an average of 25.5 points and was statistically significant (p value 0.001). In the images we observed a concavity of the groove in all the evaluated cases. CONCLUSIONS: This minimally invasive technique of deepening the groove of the peroneal tendons is reproducible, has reduced operating times compared to open surgery and has excellent results. This is a noninvasive treatment alternative for dislocation of peroneal tendons.


Assuntos
Traumatismos do Tornozelo , Luxações Articulares , Traumatismos dos Tendões , Humanos , Estudos Retrospectivos , Tendões
13.
Acta Cir Bras ; 35(10): e202001007, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33237178

RESUMO

PURPOSE: Previous studies have questioned whether the triceps brachii muscle tendon (TBMT) has a double or single insertion on the ulna. Aiming to provide an answer, we describe the anatomy of the TBMT and review a magnetic resonance imaging (MRI) series of the elbow. METHODS: Forty-one elbows were dissected to assess the details of the triceps brachii insertion. Elbow plastination slices were analyzed to determine whether there was a space on the TBMT. Magnetic resonance imaging from the records of the authors were also obtained to demonstrate the appearance of the pre-tricipital space on MRI. RESULTS: A virtual space on the medial aspect near the TBTM insertion site in the olecranon was consistently found on anatomic dissections. It was a distal pre-tricipital space. Magnetic resonance imaging demonstrated the appearance of the pre-tricipital space on MRI, and its extension was measured longitudinally either in elbow flexion or extension. There was no statistically significant difference between the measurements of this space in the right and left elbows or between flexion and extension (p > 0.05). The coefficient of variation was <10% for all measurements. CONCLUSION: Knowledge of this structure may be essential to avoid incorrect diagnosis and unnecessary therapeutic interventions.


Assuntos
Articulação do Cotovelo , Músculo Esquelético , Cotovelo , Articulação do Cotovelo/diagnóstico por imagem , Imagem por Ressonância Magnética , Músculo Esquelético/diagnóstico por imagem , Tendões/diagnóstico por imagem
14.
Arthroscopy ; 36(11): 2831, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33172582

RESUMO

Modification of the Patte rotator cuff tear classification by using 2 coronal cuts to judge severity of retraction can help differentiate repairable from irreparable rotator cuff tears and allow for more accurate tear pattern identification.


Assuntos
Lesões do Manguito Rotador , Humanos , Imagem por Ressonância Magnética , Manguito Rotador/diagnóstico por imagem , Manguito Rotador/cirurgia , Lesões do Manguito Rotador/diagnóstico por imagem , Ruptura , Tendões
15.
Zhonghua Yan Ke Za Zhi ; 56(11): 853-858, 2020 Nov 11.
Artigo em Chinês | MEDLINE | ID: mdl-33152844

RESUMO

Objective: To investigate the long-term clinical efficacy and safety of the bilateral superior oblique tendon suture spacer in treatment of A-pattern strabismus with superior oblique overaction (SOOA). Methods: Retrospective case series study. Twenty-one A-pattern strabismus patients who received the quantitative bilateral superior oblique tendon suture spacer with a complete follow-up from January 2009 to August 2017 were enrolled. Among these patients, 19 were exotropic and 2 were esotropic, including 11 males and 10 females, aged (14±9) years. Patients with unilateral superior oblique overaction, Broun syndrome or Helveston syndrome were excluded. The A-pattern strabismus, objective torsion, function of the superior oblique muscle and binocular vision were examined pre-and post-operatively. Paired t-test was used for normal distribution data, Wilcoxon rank-sum test was used for non-normal distribution data, Spearman rank correlation test and simple linear regression were used to analyze the correlation between the two variables. Results: The follow-up was 12 to 109 months (mean, 26±17 months). Twenty patients showed good alignment in the primary position with a deviation angle less than 10 prism diopter (PD), and 1 patient with esotropia had an angle greater than 15 PD. All the patients had no A pattern after surgery. The average pre-and post-operative A-patterns were (23.81±9.47) PD and (0.90±3.59) PD (t=11.29, P<0.01), respectively, and the average corrected A pattern was (23.52±9.68) PD.The average pre-and post-operative torsion was 3.18°±3.26° and -4.81°±4.13° (t=8.87, P<0.01), espectively, and the average corrected torsion was 7.95°±3.88°. No patient complained of torsional diplopia after surgery. The average amount of pre-and post-operative SOOA was 3.0 (2.0) and 0.0 (1.0) in 42 eyes (Z=-5.78, P<0.01), respectively. Suture extension of the superior oblique tendon was related with the pre-operative SOOA (r=0.47, P<0.01), but was not related with the pre-operative torsion (r=0.02, P=0.88). The linear regression results was suture extension=2.71× the grade of pre-operative SOOA (t=27.93, P<0.01). Conclusions: The bilateral superior oblique tendon suture spacer can improve the A-pattern, objective torsion and SOOA, with no torsional diplopia or V pattern after the long-term follow-up. It is a safe and effective superior oblique muscle weakening procedure. (Chin J Ophthalmol, 2020, 56: 853-858).


Assuntos
Músculos Oculomotores , Estrabismo , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Músculos Oculomotores/cirurgia , Procedimentos Cirúrgicos Oftalmológicos , Estudos Retrospectivos , Estrabismo/cirurgia , Suturas , Tendões/cirurgia , Resultado do Tratamento , Visão Binocular , Adulto Jovem
16.
Am J Vet Res ; 81(9): 714-719, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33112169

RESUMO

OBJECTIVE: To evaluate the effect of suture caliber on the tensile strength of tenorrhaphies performed with a locking-loop technique in cadaveric canine tendons. SAMPLE: 60 superficial digital flexor tendons (SDFTs) from 30 cadaveric adult dogs. PROCEDURES: Transverse tenotomy was performed, and SDFTs were repaired with a locking-loop technique and polypropylene suture of 5 randomly assigned calibers: size-0, 2-0, 3-0, 4-0, or 5-0 (n = 12 SDFTs/suture caliber). Tendon constructs were tested to failure. Yield, peak, and failure forces and causes of failure were compared between groups. RESULTS: Mean ± SD failure force for the constructs was significantly greater with large-caliber suture (size-0: 73.5 ± 3.1 N; size 2-0: 54.4 ± 7.1 N; size 3-0: 28.7 ± 4.9 N; size 4-0: 18.7 ± 3.4 N; and size 5-0: 8.8 ± 2.8 N). The likelihood of construct failure by suture pullout through the tendon substance increased with large-caliber suture (size-0: 12/12), whereas the likelihood of construct failure by suture breakage increased with small-caliber suture (2-0: 10/12; 3-0, 4-0, and 5-0: 12/12 each). CONCLUSIONS AND CLINICAL RELEVANCE: Large-caliber suture had greater tensile strength for tenorrhaphies performed with a locking-loop technique in cadaveric canine tendons. Prior to the use of large-caliber suture in patients requiring tenorrhaphy, however, in vivo studies are required to confirm the results obtained here.


Assuntos
Doenças do Cão , Traumatismos dos Tendões , Animais , Fenômenos Biomecânicos , Cadáver , Cães , Técnicas de Sutura/veterinária , Suturas/veterinária , Traumatismos dos Tendões/cirurgia , Traumatismos dos Tendões/veterinária , Tendões/cirurgia , Resistência à Tração
17.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 4680-4686, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33019038

RESUMO

Passive elastic elements can contribute to stability, energetic efficiency, and impact absorption in both biological and robotic systems. They also add dynamical complexity which makes them more challenging to model and control. The impact of this added complexity to autonomous learning has not been thoroughly explored. This is especially relevant to tendon-driven limbs whose cables and tendons are inevitably elastic. Here, we explored the efficacy of autonomous learning and control on a simulated bio-plausible tendon-driven leg across different tendon stiffness values. We demonstrate that increasing stiffness of the simulated muscles can require more iterations for the inverse map to converge but can then perform more accurately, especially in discrete tasks. Moreover, the system is robust to subsequent changes in muscle stiffnesses and can adapt on-the-go within 5 attempts. Lastly, we test the system for the functional task of locomotion and found similar effects of muscle stiffness to learning and performance. Given that a range of stiffness values led to improved learning and maximized performance, we conclude the robot bodies and autonomous controllers-at least for tendon-driven systems-can be co-developed to take advantage of elastic elements. Importantly, this opens also the door to development efforts that recapitulate the beneficial aspects of the co-evolution of brains and bodies in vertebrates.


Assuntos
Procedimentos Cirúrgicos Robóticos , Robótica , Animais , Elasticidade , Músculo Esquelético , Tendões
18.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 4687-4693, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33019039

RESUMO

Error feedback is known to improve performance by correcting control signals in response to perturbations. Here we show how adding simple error feedback can also accelerate and robustify autonomous learning in a tendon-driven robot. We have implemented two versions of the General-to-Particular (G2P) autonomous learning algorithm using a tendon-driven leg with two joints and three tendons: one with and one without real-time kinematic feedback. We have performed a rigorous study on the performance of each system, for both simulation and physical implementation cases, over a wide range of tasks. As expected, feedback improved performance in simulation and hardware. However, we see these improvements even in the presence of sensory delays of up to 100 ms and when experiencing substantial contact collisions. Importantly, feedback accelerates learning and enhances G2P's continual refinement of the initial inverse map by providing the system with more relevant data to train on. This allows the system to perform well even after only 60 seconds of initial motor babbling.


Assuntos
Algoritmos , Retroalimentação Sensorial , Fenômenos Biomecânicos , Retroalimentação , Tendões
19.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 4694-4699, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33019040

RESUMO

Determining how the nervous system controls tendon-driven bodies remains an open question. Stochastic optimal control (SOC) has been proposed as a plausible analogy in the neuroscience community. SOC relies on solving the Hamilton-Jacobi-Bellman equation, which seeks to minimize a desired cost function for a given task with noisy controls. We evaluate and compare three SOC methodologies to produce tapping by a simulated planar 3-joint human index finger: iterative Linear Quadratic Gaussian (iLQG), Model-Predictive Path Integral Control (MPPI), and Deep Forward-Backward Stochastic Differential Equations (FBSDE). We show that averaged over 128 repeats these methodologies can place the fingertip at the desired final joint angles but-because of kinematic redundancy and the presence of noise-they each have joint trajectories and final postures with different means and variances. iLQG in particular, had the largest kinematic variance and departure from the final desired joint angles. We demonstrate that MPPI and FBSDE have superior performance for such nonlinear, tendon-driven systems with noisy controls.Clinical relevance- The mathematical framework provided by MPPI and FBSDE may be best suited for tendon-driven anthropomorphic robots, exoskeletons, and prostheses for amputees.


Assuntos
Algoritmos , Tendões , Fenômenos Biomecânicos , Dedos , Humanos , Distribuição Normal
20.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 4770-4774, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33019057

RESUMO

Recording muscle tendon junction displacements during movement, allows separate investigation of the muscle and tendon behaviour, respectively. In order to provide a fully-automatic tracking method, we employ a novel deep learning approach to detect the position of the muscle tendon junction in ultrasound images. We utilize the attention mechanism to enable the network to focus on relevant regions and to obtain a better interpretation of the results. Our data set consists of a large cohort of 79 healthy subjects and 28 subjects with movement limitations performing passive full range of motion and maximum contraction movements. Our trained network shows robust detection of the muscle tendon junction on a diverse data set of varying quality with a mean absolute error of 2.55 ± 1 mm. We show that our approach can be applied for various subjects and can be operated in real-time. The complete software package is available for open-source use.


Assuntos
Aprendizado Profundo , Tendões , Humanos , Movimento , Amplitude de Movimento Articular , Tendões/diagnóstico por imagem , Ultrassonografia
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