New bioreactor for mechanical stimulation of cultured tendon-like constructs: design and validation.

OBJECTIVE: Although several different types of bioreactors are currently available with mechanical stimulation of constructs or prostheses for tendon regeneration, they are in many cases expensive and difficult to operate. This paper proposes a simple bioreactor to mechanically stimulate up to three constructs for tendon and ligament repair, composed of a stainless-steel frame and an electric motor. METHODS: The deformation is produced by a cam wheel, whose eccentricity defines the maximum deformation. The test samples, braids of PLA seeded in surface with mouse fibroblasts, are immersed in the culture medium during mechanical stimulation. RESULTS: Its advantages over existing similar bioreactor designs include: easy renewal of the culture medium and an external electric motor to avoid heating and contamination issues. After 14 days of stretching, the culture samples showed enhanced cellular proliferation and cell fiber alignment in addition to higher production of type I collagen. The cells initially seeded on the braid surface migrated to the inside of the braid. CONCLUSION: Although the results obtained have a poor statistical basis, they do suggest that the bioreactor could be usefully applied to stimulate constructs for tendon and ligament repair. Anyway, further experiments should be conducted in the future.

A study of reproducibility of kinesiology tape applications: review, reliability and validity.

BACKGROUND: Literature addressing the mechanical properties of kinesiology tape is quite scarce. There are no studies which focus on the mechanical characteristics of kinesiology tape, its mechanical properties, nor its adherence following the ISO international standard test methods for tape elongation. METHODS: This study quantified the mechanical characteristics of 380 samples of kinesiology tape from 19 different brands and in 4 different colors using a dynamometer. Mechanical testing was controlled by UNE EN ISO 13934-1. RESULTS: Significant differences were found between tape brands in terms of grammage, maximum force tenacity, work, pre-elongation and percentage elongation (P < .001). Regarding kinesiology tape color, statistically significant differences were found between tape brands in terms of grammage, maximum force and tenacity (P < .001), work and pre-elongation (P < .05). When adherence was studied, statistically significant differences were found between tape brands in terms of maximum force and work (P < .001). CONCLUSIONS: The different kinesiology tapes presented different behaviors with regard to rupture and removal when applied to skin in dry state, wet state and after being submerged in artificial acidic sweat solution. Therefore, different kinesiology tape brands will produce different levels of strain even though the same elongation is used. Depending on the characteristics (body dimensions) and properties (skin elongation) of each subject in the sample, bandages with different elongations must be applied to achieve the same strain in all of the tapes and therefore produce the same effect. The absence of these data at this time limits the reliability of previous clinical studies, makes comparing their findings impossible and presents new challenges for research in this field.

Lesiones deportivas de la muñeca y mano / Sports injuries of the wrist and hand

El objetivo de este trabajo es exponer de un modo sistemático, las lesiones deportivas más frecuentes o más graves de la mano y la muñeca, presentando los tratamientos basados en métodos sencillos y seguros. Las lesiones de la mano representan una gran proporción de todas las lesiones que acuden a los servicios de urgencias (aproximadamente un tercio). En los deportistas, son particularmente frecuentes las lesiones por avulsión del flexor profundo, el dedo en martillo (lesión cerrada más común del deportista), las roturas de la placa volar, o las lesiones de los ligamentos colaterales. Se revisan además las tendinitis y tendinosis, luxaciones tendineas a distintos niveles, neuropatías de los nervios mediano, cubital y colaterales digitales, síndrome de impactación cubito carpiano, esguinces, fracturas y luxaciones articulares, deformidades más comunes de los dedos (Boutonnière, Jersey finger, mallet finger y dedo caído), los esguinces e inestabilidades carpianas y las lesiones del fibrocartílago triangular. La evaluación de las lesiones óseas debe iniciarse con unas radiografías simples. La TAC debe reservarse para la comprensión de las lesiones óseas complejas. La ecografía y la resonancia para el estudio de los tejidos blandos. Se exponen los tratamientos más comunes con la idea de que sirva como una guía rápida para enfocar estas lesiones a pie de pista. La mayoría de mecanismos de lesión de las manos relacionados con el deporte se pueden prevenir. La literatura actual sugiere que los esfuerzos dirigidos al cambio de reglas en los distintos deportes para conseguir entornos de juego más seguros, así como los cambios en la educación y formación de entrenadores, deportistas y personal sanitario minimizan los riesgos de lesión

The aim of this work is to expose systematically the most frequent or severe sports injuries of the hand, presenting treatments based on simple and safe. Hand injuries account for a large proportion of injuries treated in the emergency departments (approximately one third). In athletes, particularly frequent avulsion injuries are deep flexor, mallet finger (closed most common injury of the athlete), the volar plate ruptures, or collateral ligament injuries. Tendinitis and tendinosis, tendinous dislocations at different levels, neuropathy of median, ulnar and digital collateral, impactation ulnar carpal syndrome, sprains, fractures and joint dislocations, common deformities of the fingers (Boutonnière, Jersey finger, mallet finger and thumb down), carpal instabilities, sprains and injuries of the triangular fibrocartilage are reviewed. The evaluation of bone lesions should start with a plain radiographs. The CT-scan should be reserved for the understanding of complex bone lesions. Ultrasound and MRI are recommended for the study of soft tissue injuries. The most common treatment protocols are addressed that constitutes a rapid guide to assess all these lesions at the course. Most injury mechanisms related to the different hand lesions in sports are preventable. The current literature suggests that some efforts should be done to change rules in different sports to get safer playing environments. Changes in the education and training of coaches, athletes and healthcare personnel are needed to minimize the risk of injury

Comportamiento mecánico de 3 tipos de anudados quirúrgicos usando monofilamentos de 4/0 / Mechanical behaviour of three types of surgical knots using 4/0 monofilament

Objetivo Estudiar experimentalmente mediante ensayos mecánicos el comportamiento de 4 tipos de monofilamento con 3 diseños de nudo, muy frecuentemente utilizados en cirugía. Material y métodos Se eligieron 4 monofilamentos de 4/0, dos de nailon y otros dos de polipropileno. Sobre cada hilo se realizaron 3 diseños de nudo. Un primer diseño (D-S-S) consistía en un seminudo doble (D) seguido de uno simple (S) en dirección contraria y un tercer S a su vez en dirección contraria. La configuración del segundo diseño fue D-S-D, y la del tercero, S-S-D. Se realizó un ensayo mecánico de rotura por estiramiento del hilo a una velocidad de 4N/s, registrándose la fuerza y la deformación en intervalos de 100ms.ResultadosEn los ensayos sobre hilos con nudos, existía una disminución de la fuerza y deformación de rotura con relación a los hilos sin nudos. En todos los casos, la rotura del hilo se producía en la zona del nudo, presumiblemente debido a daños causados al hilo durante el proceso de anudado. El nudo D-S-D fue el que mayor resistencia presentó con hilos de polipropileno, y el S-S-D el que mayor resistencia proporcionó con hilos de nailon. Conclusiones Los hilos de polipropileno, con nudos D-S-D, estarían más indicados para suturar tejidos que debieran soportar grandes fuerzas y con poca deformación de la sutura (por ejemplo, tendones). Los hilos de nailon, con nudos S-S-D, estarían mejor indicados para tejidos que tuvieran que soportar fuerzas más pequeñas y que precisaran de mayor elasticidad (por ejemplo, piel) (AU)

Objective To experimentally study the behaviour of 4 types of monofilament with 3 knotting techniques, very often used in surgery, employing mechanical tests. Material and methods Four 4/0 monofilaments were chosen, two of nylon, and the other two of polypropylene. Three types of knot designs were made with each thread. The first design (D-S-S) consisted of a double half-knot (D) followed by one single (S) in the opposite direction, a third S in turn in the opposite direction. The configuration of the second design was D-S-D, and the third, S-S-D. A mechanical fracture test was performed by stretching the thread at a rate of 4N/s, the force and deformation being recorded at intervals of 100ms.ResultsThere was a decrease in the force and deformation in the tests on threads with knots compared to threads without knots. In all cases the rupture of the thread occurred in the knot area, presumably due to damage caused to the thread during the knotting process. The D-S-D knot had the greatest resistance with polypropylene threads, and S-S-D provided the greatest resistance with nylon threads Conclusions Polypropylene threads, with D-S-D knots, should be more indicated to suture tissues that have to support great forces and with little deformation of the suture (e.g., tendons). Nylon threads, with S-S-D knots, would be better indicated for tissues that have to support smaller forces and that require greater elasticity (e.g., skin) (AU)

[Mechanical behaviour of three types of surgical knots using 4/0 monofilament]. / Comportamiento mecánico de 3 tipos de anudados quirúrgicos usando monofilamentos de 4/0.

OBJECTIVE: To experimentally study the behaviour of 4 types of monofilament with 3 knotting techniques, very often used in surgery, employing mechanical tests. MATERIAL AND METHODS: Four 4/0 monofilaments were chosen, two of nylon, and the other two of polypropylene. Three types of knot designs were made with each thread. The first design (D-S-S) consisted of a double half-knot (D) followed by one single (S) in the opposite direction, a third S in turn in the opposite direction. The configuration of the second design was D-S-D, and the third, S-S-D. A mechanical fracture test was performed by stretching the thread at a rate of 4N/s, the force and deformation being recorded at intervals of 100 ms. RESULTS: There was a decrease in the force and deformation in the tests on threads with knots compared to threads without knots. In all cases the rupture of the thread occurred in the knot area, presumably due to damage caused to the thread during the knotting process. The D-S-D knot had the greatest resistance with polypropylene threads, and S-S-D provided the greatest resistance with nylon threads CONCLUSIONS: Polypropylene threads, with D-S-D knots, should be more indicated to suture tissues that have to support great forces and with little deformation of the suture (e.g., tendons). Nylon threads, with S-S-D knots, would be better indicated for tissues that have to support smaller forces and that require greater elasticity (e.g., skin).