Arthroscopic stabilisation of an acute acromioclavicular dislocation grade III in a patient with ectopic insertion of the pectoralis minor: technical considerations

The different approaches used in arthroscopic stabilisation of the acromioclavicular joint are well known. However, and despite a great incidence of ectopic pectoralis minor insertion, an alternative choice for the use of arthroscopic portal has not being sufficiently described. Here, we describe a case of acute acromioclavicular dislocation grade III. The arthroscopic stabilisation was achieved using the TightRope (Arthrex, Naples, USA) implant. Through this technique, the approach to the articular portion of the coracoid process can be made intra-articularly or from the subacromial space. We accessed intra-articularly, by opening the rotator interval to reach the coracoid process from the joint cavity. After opening the rotator interval, an ectopic insertion of the pectoralis minor was observed. The choice of approach of the coracoid process from the subacromial space would have complicated the intervention, making it necessary to sever the ectopic tendon to complete the technique, lengthening the surgical time and increasing the chance of complications. For this reason, the use of a standard posterior portal providing intra-articular arthroscopic access through the rotator interval is recommended since the aforementioned anatomical variation is not infrequent. Level of evidence Therapeutic studies—investigating the results of treatment, Level V.

Composición corporal y somatotipo en triatletas universitarios

Introducción: el triatlón es un deporte de resistencia e individual que está formado por tres disciplinas diferentes: natación, ciclismo y carrera a pie. El objetivo del estudio es describir las características antropométricas en triatletas varones universitarios, además de analizar y describir la composición corporal y el somatotipo de dichos triatletas. Metodología: estudio observacional y descriptivo de las características antropométricas, la composición corporal y el somatotipo de 39 triatletas varones universitarios entre 24 ± 4,5 años, participantes en el campeonato de España universitario de triatlón, modalidad sprint (Alicante 2010), procedentes de diferentes universidades españolas. Según la técnicas de medición antropométrica adoptadas por la International Society for the Advancement of Kinanthropometry (ISAK) y el Grupo Español de Cineantropometría (GREC) por un evaluador acreditado ISAK de nivel II. Resultados: nos encontramos con deportistas de talla baja, en los que destacan valores inferiores a lo normal en los pliegues cutáneos subescapular, supraespinal, tricipital y bicipital, un porcentaje de masa muscular (45,27 ± 3,29%), de masa grasa (10,22 ± 2,92%) y de masa ósea (16,65 ± 1,34%) y un somatotipo en el que predomina la mesomorfia. Discusión: los triatletas y corredores presentan más baja talla que los ciclistas y nadadores. Los triatletas y ciclistas muestran un peso similar, siendo menor que el de los nadadores de fondo y mayor que el de los corredores de 10 km. Los pliegues cutáneos cresta ilíaca, abdominal y muslo frontal de los ciclistas son inferiores al de los triatletas. El porcentaje de masa grasa de triatletas corredores y nadadores son similares; sin embargo, el de la masa muscular de los triatletas suele ser inferior al de los ciclistas pero similar a las demás modalidades. El somatotipo del triatleta se asemeja al del ciclista (mesomorfo). El del corredor es mesomorfo-ectomorfo y el del nadador puede oscilar de mesomorfo a ectomorfo.

Shoulder pain in overhead athletes : a systematic review of orthopaedic causes

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

MR morphometry of posterior tibialis muscle in adult acquired flat foot

We conducted magnetic resonance imaging of the posterior tibial (PT) and flexor digitorum longus (FDL) muscle bellies in 12 patients undergoing surgical treatment for unilateral posterior tibial tendon (PTT) dysfunction. All patients had atrophy of the PT muscle compared to the normal leg (mean 10.7%, p=0.008). In those patients with a complete rupture of PTT there was replacement of the PT muscle by fatty infiltration. Conversely, the FDL muscle showed a compensatory hypertrophy (mean 17.2%, p

Temporal expression of fibroblast growth factor receptors during primary ligament repair

Following injury, it is inherently difficult to completely restore the biomechanical properties of ligaments. Relatively little is known about the cellular mechanisms controlling ligament healing. Numerous studies have implicated fibroblast growth factors (FGFs) as key molecules during the initiation of the cellular proliferation, differentiation, migration and matrix deposition that characterise wound healing. While current surgical emphasis concentrates on growth factor intervention, the role of their cognate receptors (FGFRs) has largely been overlooked. Following transection of the medial collateral ligament (MCL) in rabbits, we examined FGFR expression over a 14-day healing period. Using semiquantitative RT-PCR, we observed a significant upregulation in FGFR2 expression after 3 days. By 7 days post injury, FGFR2 expression fell to basal levels in line with those of FGFR1 and 3, both of which remained unaffected by surgical transection. These results demonstrate a role for FGFR2 in fibroblast and endothelial cell proliferation in damaged ligament, and suggest a window for FGF therapy.

The effect of weightbearing exercise with low frequency, whole body vibration on lumbosacral proprioception: A pilot study on normal subjects

Patients with low back pain (LBP) often present with impaired proprioception of the lumbopelvic region. For this reason, proprioception training usually forms part of the rehabilitation protocols. New exercise equipment that produces whole body, low frequency vibration (WBV) has been developed to improve muscle function, and reportedly improves proprioception. The aim of this pilot study was to investigate whether weightbearing exercise given in conjunction with WBV would affect lumbosacral position sense in healthy individuals. For this purpose, twenty-five young individuals with no LBP were assigned randomly to an experimental or control group. The experimental group received WBV for five minutes while holding a static, semi-squat position. The control group adopted the same weightbearing position for equal time but received no vibration. A two-dimensional motion analysis system measured the repositioning accuracy of pelvic tilting in standing. The experimental (WBV) group demonstrated a significant improvement in repositioning accuracy over time (mean 0.78 degrees) representing 39% improvement. It was concluded that WBV may induce improvements in lumbosacral repositioning accuracy when combined with a weightbearing exercise. Future studies with WBV should focus on evaluating its effects with different types of exercise, the exercise time needed for optimal outcomes, and the effects on proprioception deficits in LBP patients.

Muscle fiber and motor unit behavior in the longest human skeletal muscle

The sartorius muscle is the longest muscle in the human body. It is strap-like, up to 600 mm in length, and contains five to seven neurovascular compartments, each with a neuromuscular endplate zone. Some of its fibers terminate intrafascicularly, whereas others may run the full length of the muscle. To assess the location and timing of activation within motor units of this long muscle, we recorded electromyographic potentials from multiple intramuscular electrodes along sartorius muscle during steady voluntary contraction and analyzed their activity with spike-triggered averaging from a needle electrode inserted near the proximal end of the muscle. Approximately 30% of sartorius motor units included muscle fibers that ran the full length of the muscle, conducting action potentials at 3.9 +/- 0.1 m/s. Most motor units were innervated within a single muscle endplate zone that was not necessarily near the midpoint of the fiber. As a consequence, action potentials reached the distal end of a unit as late as 100 ms after initiation at an endplate zone. Thus, contractile activity is not synchronized along the length of single sartorius fibers. We postulate that lateral transmission of force from fiber to endomysium and a wide distribution of motor unit endplates along the muscle are critical for the efficient transmission of force from sarcomere to tendon and for the prevention of muscle injury caused by overextension of inactive regions of muscle fibers.

Disrupted cortical proprioceptive representation evokes symptoms of peculiarity, foreignness and swelling, but not pain

Objectives. It has been proposed that disruption of the internal proprioceptive representation, via incongruent sensory input, may underpin pathological pain states, but experimental evidence relies on conflicting visual input, which is not clinically relevant. We aimed to determine the symptomatic effect of incongruent proprioceptive input, imparted by vibration of the wrist tendons, which evokes the illusion of perpetual wrist flexion and disrupts cortical proprioceptive representation. Methods. Twenty-nine healthy and naive volunteers reported symptoms during five conditions: control, active and passive wrist flexion, extensor carpi radialis tendon vibration to evoke illusion of perpetual wrist flexion, and ulnar styloid (sham) vibration. No advice was given about possible illusions. Results. Twenty-one subjects reported the illusion of perpetual wrist flexion during tendon vibration. There was no effect of condition or of whether or not subjects reported an illusion on discomfort/pain (P > 0.28). Peculiarity, swelling and foreignness were greater during tendon vibration than during the other conditions, and greater during tendon vibration in those who reported an illusion of wrist flexion than in those who did not (P < 0.05 for all). Symptoms were reported by at least two subjects in each condition and four subjects reported systemic symptoms (e.g. nausea). Conclusions. In healthy volunteers, incongruent proprioceptive input does not cause discomfort or pain but does evoke feelings of peculiarity, swelling and foreignness in the limb.

Preparation and characterisation of novel polycaprolactone-chitosan blends

This research paper reports on the production of a biocompatible and biodegradable material to be used in a polymer stent used for counteracting the occurrence of anastomotic leakage following gastrointestinal surgery. Chitosan was blended with polycaprolactone in a solvent mixture of acetic acid and water. Membranes were formed with a range of 50/50%, 60/40%, 65/35%, 70/30% and 80/20% polycaprolactone/chitosan. The tensile properties of the blends were examined over a time period to access material degradation. In addition the biocompatibilities of the polycaprolactone/chitosan blends were tested for cytotoxic effect using primary tendon fibroblastic cells. This research concluded that the polycaprolactone/chitosan was non-toxic to the fibroblasts cells in-vitro. Analysis of the mechanical properties of the blends showed a range of mechanical strengths and polymer life spans. Overall, blends of 65/35%, 70/30% and 80/20% polycaprolactone/chitosan emerged as possible candidates for the production of a gastrointestinal stent. © 2011 Inderscience Enterprises Ltd.

Efeitos da terapia laser de baixa intensidade associada ao exercício aeróbio no reparo de tenotomia do tendão de aquiles de ratos diabéticos

Diabetes Mellitus (DM ) is a complex disease that requires continuous medical care for the reduction of risk factors in addition to glycemic control. The typical hyperglycemia of this disease produces glycosylation of proteins and so the consequence is the accumulation of glycosylation final products in various human tissues, among them, the tendon. The aerobic exercise (AE) and the low level laser therapy (LLLT) have been used to treat tendinopathies in individuals with or without DM. Objective: The aim of this study was to watch the effect of the LLLT and the AE, in association, in partial tenotomy of the tissue repair of the Achilles tendon (AT) of diabetic rats. Methods: 91 animals were utilized and divided in to the following groups: control group (GC), injured control group (GCL), diabetic group (GD), diabetic group LLLT (GD – TLBI), diabetic group trained (GD - EX) and diabetic group trained laser (GD-EX+TLBI). The animals were submitted to intervention with AE, using a protocol with a progressive increase of time (12 to 60 min) and speed of (4 to 9 m/min), and the LLLT (660 nm laser, 10mW, 4 J/cm², single point for 16 seconds, three times for week). It was analyzed morphological, biomechanical and molecular characteristics. For data showing normal distribution was used one-way ANOVA test and post hoc Tukey and data without normal distribution was used Mann Whitney test and post hoc Dunn's. It was accepted p <0.05 for statistical significance Results: The biomechanical tests indicated major improvement in the GC and GD-EX+TLBI groups when compared with the diabetic groups in the following variables: maximum load, strain, absorbed energy, stress, cross section area, elastic modulus and energy density (p<0.05). The analysis through molecular biology indicated that the association of aerobic exercise and LLLT generated an increase of the collagen I gene expression and modulated the expression of the MMP2 and MMP9 (p<0.05). No observed any major improvement in the morphological variable studied. Conclusion: the LLLT associated with aerobic exercise promotes and increase of the mechanical properties, in the control of collagen I gene expression and of the MMP2 and MMP9 of the diabetic rats.

Dynamic effects of anchor positional tolerance on tension moored floating wind turbine

For water depths greater than 60m floating wind turbines will become the most economical option for generating offshore wind energy. Tension mooring stabilised units are one type of platform being considered by the offshore wind energy industry. The complex mooring arrangement used by this type of platform means that the dynamics are greatly effected by offsets in the positioning of the anchors. This paper examines the issue of tendon anchor position tolerances. The dynamic effects of three positional tolerances are analysed in survival state using the time domain FASTLink. The severe impact of worst case anchor positional offsets on platform and turbine survivability is shown. The worst anchor misposition combinations are highlighted and should be strongly avoided. Novel methods to mitigate this issue are presented.

Mechanical properties and cellular response of novel electrospun nanofibers for ligament tissue engineering: Effects of orientation and geometry

Electrospun nanofibers are a promising material for ligamentous tissue engineering, however weak mechanical properties of fibers to date have limited their clinical usage. The goal of this work was to modify electrospun nanofibers to create a robust structure that mimics the complex hierarchy of native tendons and ligaments. The scaffolds that were fabricated in this study consisted of either random or aligned nanofibers in flat sheets or rolled nanofiber bundles that mimic the size scale of fascicle units in primarily tensile load bearing soft musculoskeletal tissues. Altering nanofiber orientation and geometry significantly affected mechanical properties; most notably aligned nanofiber sheets had the greatest modulus; 125% higher than that of random nanofiber sheets; and 45% higher than aligned nanofiber bundles. Modifying aligned nanofiber sheets to form aligned nanofiber bundles also resulted in approximately 107% higher yield stresses and 140% higher yield strains. The mechanical properties of aligned nanofiber bundles were in the range of the mechanical properties of the native ACL: modulus=158±32MPa, yield stress=57±23MPa and yield strain=0.38±0.08. Adipose derived stem cells cultured on all surfaces remained viable and proliferated extensively over a 7 day culture period and cells elongated on nanofiber bundles. The results of the study suggest that aligned nanofiber bundles may be useful for ligament and tendon tissue engineering based on their mechanical properties and ability to support cell adhesion, proliferation, and elongation.

Human Fetal Progenitor Tenocytes for Regenerative Medicine.

Tendon injuries are very frequent and affect a wide and heterogeneous population. Unfortunately, the healing process is long with outcomes that are not often satisfactory due to fibrotic tissue appearance, which leads to scar and adhesion development. Tissue engineering and cell therapies emerge as interesting alternatives to classical treatments. In this study, we evaluated human fetal progenitor tenocytes (hFPTs) as a potential cell source for treatment of tendon afflictions, as fetal cells are known to promote healing in a scarless regenerative process. hFPTs presented a rapid and stable growth up to passage 9, allowing to create a large cell bank for off-the-shelf availability. hFPTs showed a strong tenogenic phenotype with an excellent stability, even when placed in conditions normally inducing cells to differentiate. The karyotype also indicated a good stability up to passage 12, which is far beyond that necessary for clinical application (passage 6). When placed in coculture, hFPTs had the capacity to stimulate human adult tenocytes (hATs), which are responsible for the deposition of a new extracellular matrix during tendon healing. Finally, it was possible to distribute cells in porous or gel scaffolds with an excellent survival, thus permitting a large variety of applications (from simple injections to grafts acting as filling material). All of these results are encouraging in the development of an off-the-shelf cell source capable of stimulating tendon regeneration for the treatment of tendon injuries.