Operative Treatment of Acute Fractures of the Tarsal Navicular Body: Midterm Results With a New Classification.

BACKGROUND Treatment of displaced tarsal navicular body fractures usually consists of open reduction and internal fixation. However, there is little literature reporting results of this treatment and correlation to fracture severity. METHODS We report the results of 24 patients treated in our institution over a 12-year period. Primary outcome measurements were Visual-Analogue-Scale Foot and Ankle score (VAS-FA), AOFAS midfoot score, and talonavicular osteoarthritis at final follow-up. According to a new classification system reflecting talonavicular joint damage, 2-part fractures were classified as type I, multifragmentary fractures as type II, and fractures with talonavicular joint dislocation and/or concomitant talar head fractures as type III. Spearman's coefficients tested this classification's correlation with the primary outcome measurements. Mean patient age was 33 (range 16-61) years and mean follow-up duration 73 (range 24-159) months. RESULTS Average VAS-FA score was 74.7 (standard deviation [SD] 16.9), and average AOFAS midfoot score was 83.8 (SD = 12.8). Final radiographs showed no talonavicular arthritis in 5 patients, grade 1 in 7, grade 2 in 3, grade 3 in 6, and grade 4 in 1 patient. Two patients had secondary or spontaneous talonavicular fusion. Spearman coefficients showed strong correlation of the classification system with VAS-FA score (r = -0.663, P < .005) and talonavicular arthritis (r = 0.600, P = .003), and moderate correlation with AOFAS score (r = -.509, P = .011). CONCLUSION At midterm follow-up, open reduction and internal fixation of navicular body fractures led to good clinical outcome but was closely related to fracture severity. A new classification based on the degree of talonavicular joint damage showed close correlation to clinical and radiologic outcome. LEVEL OF EVIDENCE Level IV, retrospective case series.

First Metatarsophalangeal Joint Degeneration: Arthroscopic Treatment

Arthroscopic treatment of hallux rigidus is appropriate after failed nonoperative treatment. Debridement with cheilectomy, and fusion are the main indications for arthroscopic treatment of hallux rigidus. If the cartilage damage is extensive and the patient has consented, then a fusion is performed at the same sitting.

Temporary Internal Fixation for Ligamentous and Osseous Lisfranc Injuries: Outcome and Technical Tip

BACKGROUND Open rather than closed reduction and internal fixation as well as primary definitive arthrodesis are well accepted for ligamentous and osseous Lisfranc injuries. For ligamentous injuries, a better outcome after primary definitive partial arthrodesis has been published. METHODS Of 135 Lisfranc injuries that were treated from 1998 to 2012 with open reduction, temporary internal fixation by screws and plates, and restricted weight bearing in a lower leg cast for 3 months followed by an arch support for another 4 to 6 weeks, 29 ligamentous Lisfranc injuries were available for follow-up. They were compared with 29 osseous Lisfranc injuries matched in age and gender. RESULTS Between the groups, there were no significant differences in average age (39.9 vs 38 years) or in average follow-up time (8.3 vs 9.1 years). Also, no significant differences were seen in the AOFAS midfoot score (84 vs 85.3 points), the FFI pain scale (9.9 vs 14.9 points), SF 36 physical component (56.2 vs 53.9 points), SF 36 mental component (57 vs 56.4 points), or VAS for pain (1.6 vs 1.5 points). The FFI function scale was significantly lower in the ligamentous group (11.6 vs 19.5 points). Radiographically, loss of reduction was recorded 3 times in the ligamentous injuries and 4 times in the osseous injuries. Arthritis was mild/moderate/severe in 5/3/0 ligamentous injuries and in 7/2/1 osseous injuries, requiring 1 definitive secondary Lisfranc arthrodesis in each group. CONCLUSION With longer and conservative postoperative management, open reduction and temporary internal fixation in ligamentous and osseous Lisfranc injuries led to equal medium-term outcome. Inferior outcome in ligamentous injuries was not found. LEVEL OF EVIDENCE Level III, retrospective comparative cohort study.

Non-surgical treatment of pain associated with posterior tibial tendon dysfunction: study protocol for a randomised clinical trial

BACKGROUND Symptoms associated with pes planovalgus or flatfeet occur frequently, even though some people with a flatfoot deformity remain asymptomatic. Pes planovalgus is proposed to be associated with foot/ankle pain and poor function. Concurrently, the multifactorial weakness of the tibialis posterior muscle and its tendon can lead to a flattening of the longitudinal arch of the foot. Those affected can experience functional impairment and pain. Less severe cases at an early stage are eligible for non-surgical treatment and foot orthoses are considered to be the first line approach. Furthermore, strengthening of arch and ankle stabilising muscles are thought to contribute to active compensation of the deformity leading to stress relief of soft tissue structures. There is only limited evidence concerning the numerous therapy approaches, and so far, no data are available showing functional benefits that accompany these interventions. METHODS After clinical diagnosis and clarification of inclusion criteria (e.g., age 40-70, current complaint of foot and ankle pain more than three months, posterior tibial tendon dysfunction stage I & II, longitudinal arch flattening verified by radiography), sixty participants with posterior tibial tendon dysfunction associated complaints will be included in the study and will be randomly assigned to one of three different intervention groups: (i) foot orthoses only (FOO), (ii) foot orthoses and eccentric exercise (FOE), or (iii) sham foot orthoses only (FOS). Participants in the FOO and FOE groups will be allocated individualised foot orthoses, the latter combined with eccentric exercise for ankle stabilisation and strengthening of the tibialis posterior muscle. Participants in the FOS group will be allocated sham foot orthoses only. During the intervention period of 12 weeks, all participants will be encouraged to follow an educational program for dosed foot load management (e.g., to stop activity if they experience increasing pain). Functional impairment will be evaluated pre- and post-intervention by the Foot Function Index. Further outcome measures include the Pain Disability Index, Visual Analogue Scale for pain, SF-12, kinematic data from 3D-movement analysis and neuromuscular activity during level and downstairs walking. Measuring outcomes pre- and post-intervention will allow the calculation of intervention effects by 3×3 Analysis of Variance (ANOVA) with repeated measures. DISCUSSION The purpose of this randomised trial is to evaluate the therapeutic benefit of three different non-surgical treatment regimens in participants with posterior tibial tendon dysfunction and accompanying pes planovalgus. Furthermore, the analysis of changes in gait mechanics and neuromuscular control will contribute to an enhanced understanding of functional changes and eventually optimise conservative management strategies for these patients. TRIAL REGISTRATION ClinicalTrials.gov Protocol Registration System: ClinicalTrials.gov ID NCT01839669.

Endothelial progenitor cells as a biological marker of peripheral artery disease.

The role of endothelial progenitor cells (EPCs) in peripheral artery disease (PAD) remains unclear. We hypothesized that EPC mobilization and function play a central role in the development of endothelial dysfunction and directly influence the degree of atherosclerotic burden in peripheral artery vessels. The number of circulating EPCs, defined as CD34(+)/KDR(+) cells, were assessed by flow cytometry in 91 subjects classified according to a predefined sample size of 31 non-diabetic PAD patients, 30 diabetic PAD patients, and 30 healthy volunteers. Both PAD groups had undergone endovascular treatment in the past. As a functional parameter, EPC colony-forming units were determined ex vivo. Apart from a broad laboratory analysis, a series of clinical measures using the ankle-brachial index (ABI), flow-mediated dilatation (FMD) and carotid intima-media thickness (cIMT) were investigated. A significant reduction of EPC counts and proliferation indices in both PAD groups compared to healthy subjects were observed. Low EPC number and pathological findings in the clinical assessment were strongly correlated to the group allocation. Multivariate statistical analysis revealed these findings to be independent predictors of disease appearance. Linear regression analysis showed the ABI to be a predictor of circulating EPC number (p=0.02). Moreover, the functionality of EPCs was correlated by linear regression (p=0.017) to cIMT. The influence of diabetes mellitus on EPCs in our study has to be considered marginal in already disease-affected patients. This study demonstrated that EPCs could predict the prevalence and severity of symptomatic PAD, with ABI as the determinant of the state of EPC populations in disease-affected groups.

An analysis of IN.PACT DEEP randomized trial on the limitations of the societal guidelines-recommended hemodynamic parameters to diagnose critical limb ischemia.

OBJECTIVE Recent small single-center data indicate that the current hemodynamic parameters used to diagnose critical limb ischemia are insensitive. We investigated the validity of the societal guidelines-recommended hemodynamic parameters against core laboratory-adjudicated angiographic data from the multicenter IN.PACT DEEP (RandomIzed AmPhirion DEEP DEB vs StAndard PTA for the treatment of below the knee Critical limb ischemia) Trial. METHODS Of the 358 patients in the IN.PACT DEEP Trial to assess drug-eluting balloon vs standard balloon angioplasty for infrapopliteal disease, 237 had isolated infrapopliteal disease with an available ankle-brachial index (ABI), and only 40 of the latter had available toe pressure measurements. The associations between ABI, ankle pressure, and toe pressure with tibial runoff, Rutherford category, and plantar arch were examined according to the cutoff points recommended by the societal guidelines. Abnormal tibial runoff was defined as severely stenotic (≥70%) or occluded and scored as one-, two-, or three-vessel disease. A stenotic or occluded plantar arch was considered abnormal. RESULTS Only 14 of 237 patients (6%) had an ABI <0.4. Abnormal ankle pressure, defined as <50 mm Hg if Rutherford category 4 and <70 mm Hg if Rutherford category 5 or 6, was found only in 37 patients (16%). Abnormal toe pressure, defined as <30 mm Hg if Rutherford category 4 and <50 mm Hg if Rutherford category 5 or 6, was found in 24 of 40 patients (60%) with available measurements. Importantly, 29% of these 24 patients had an ABI within normal reference ranges. A univariate multinomial logistic regression found no association between the above hemodynamic parameters and the number of diseased infrapopliteal vessels. However, there was a significant paradoxic association where patients with Rutherford category 6 had higher ABI and ankle pressure than those with Rutherford category 5. Similarly, there was no association between ABI and pedal arch patency. CONCLUSIONS The current recommended hemodynamic parameters fail to identify a significant portion of patients with lower extremity ulcers and angiographically proven severe disease. Toe pressure has better sensitivity and should be considered in all patients with critical limb ischemia.

Enhancing Authenticity in Simulation Using Appropriate Techniques of Moulage

Workshop Overview The use of special effects (moulage) is a way to augment the authenticity of a scenario in simulation. This workshop will introduce different techniques of moulage (oil based cream colors, watercolors, transfer tattoos and 3D Prosthetics). The participants will have the opportunity to explore these techniques by applying various moulages. They will compare the techniques and discuss their advantages and disadvantages. Moreover, strategies for standardization and quality assurance will be discussed. Workshop Rationale Moulage supports the sensory perception in an scenario (1). It can provide evaluation clues (2) and help learners (and SPs) to engage in the simulation. However, it is of crucial importance that the simulated physical pathologies are represented accurate and reliable. Accuracy is achieved by using the appropriate technique, which requires knowledge and practice . With information about different moulage techniques, we hope to increases the knowledge of moulage during the workshop. By applying moulages in various techniques we will practice together. As standardization is critical for simulation scenarios in assessment (3, 4) strategies for standardization of moulage will be introduced and discussed. Workshop Objectives During the workshop participants will: - gain knowledge about different techniques of moulages - practice moulages in various techniques - discuss the advantages and disadvantages of moulage techniques - describe strategies for standardization and quality assurance of moulage Planned Format 5 min Introduction 15 min Overview – Background & Theory (presentation) 15 min Application of moulage for ankle sprain in 4 different techniques (oil based cream color, water color, temporary tatoo, 3D prosthetic) in small groups 5 min Comparing the results by interactive viewing of prepared moulages 15 min Application of moulages for burn in different techniques in small groups 5 min Comparing results the results by interactive viewing of prepared moulages 5 min Sharing experiences with different techniques in small groups 20 min Discussion of the techniques including standardization and quality assurance strategies (plenary discussion) 5 min Summary / Take home points

Driving and emergency braking may be impaired after tibiotalar joint arthrodesis: conclusions after a case series.

PURPOSE To assess whether reaction time (RT) and movement time (MT), as the two components of the total brake response time (TBRT) and brake force (BF) are different in patients with a foot joint arthrodesis in comparison to controls. METHODS The study was a comparative case series in a driving simulator under realistic driving conditions. Mobile patients without a walker, ≥6 months after surgery who were driving a car and had no neurological co-morbidity, knee or hip joint prosthesis were included in the study. The selection criteria resulted in 12 patients with right tibiotalar joint arthrodesis (TTJA) and 12 patients with another right foot joint arthrodesis (OFJA), who were compared to 17 individuals without any ankle-joint pathology. For TBRT, an empirical safe driving threshold of 700 ms was used. The outcome measures were RT, MT, TBRT, BF and McGuire score. RESULTS MT (p = 0.034) and TBRT (p = 0.026) were longer in TTJA patients in comparison with the controls. Also, more patients with TTJA than patients with OFJA and controls exceeded the safe driving threshold (p = 0.028). The outcomes in OFJA patients and in controls were comparable. The McGuire score was similar between the TTJA and OFJA patients (p = 0.26). CONCLUSIONS Significantly slower MT and TBRT, and significantly more patients exceeding the safe driving threshold, were observed after a tibiotalar-joint arthrodesis in comparison to the controls. Patients with OFJAs were not significantly different from the controls. Driving and emergency braking may be impaired after tibiotalar-joint arthrodesis.

Prescripción de medicamentos en las farmacias : una realidad preocupante

Se presume que la prescripción de medicamentos sin receta médica en las farmacias es una práctica frecuente. El objetivo fue conocer la conducta del personal de las farmacias ante una consulta realizada por estudiantes de medicina entrenados para actuar como pacientes simulados de las siguientes situaciones: 1: Infección respiratoria alta, 2: Diarrea aguda; 3: Disuria, 4: Ulcera genital, 5: Hipertensión arterial, 6: Cefalea aguda, 7: Artralgia de tobillo. Se efectuaron 100 entrevistas y cada una de las situaciones se realizó al menos 12 veces. En solo el 28% de los casos no se indicó tratamiento y las 72 prescripciones fueron realizadas por 38 farmacéuticos y 34 no profesionales. La medicación se consideró inadecuada en 58.3%, iatrogénica en 51.4% y la posología incorrecta en 50%. Los fármacos más indicados fueron antibióticos (23.6%), AINES (20.8%), antidiarreicos (11.8%) y antigripales (9.7%). Las situaciones 7 (100%), 1 (93.3%) y 2 (84.6%) tuvieron la mayor frecuencia de indicación de tratamiento y fue significativa la negativa a medicar en las situaciones 4 (OR, 0.16) y 5 (OR, 0.22) (p<0.05). La prescripción fue incorrecta en el 100% de las situaciones 2 y 4 y iatrogénica en el 100% de las situaciones 2, 4 y 5. En 48 casos se sugirió consulta médica y la situación 5 tuvo 4.27 veces más posibilidades de ser derivada (p= 0.01). Este estudio demuestra que en las farmacias del gran Mendoza es común la venta de medicamentos sin prescripción médica lo que compromete la seguridad y salud de las personas.

Acute effects of endurance exercise on jumping and kicking performance in top-class young soccer players

The aim of this study was to examine the acute effects of endurance exercise on jumping and kicking performance in young soccer players. Twenty-one top-class young soccer players (16.1±0.2 years) performed a countermovement jump test and a maximal instep soccer kick test before and after running for 20 min on a treadmill at 80% of their individual maximum heart rate. Two force platforms were used to obtain the following parameters during the countermovement jump: jump height, maximum power, maximum power relative to body mass, maximum vertical ground reaction force, maximum vertical ground reaction force relative to body mass, and maximum vertical ground reaction force applied to each leg. Maximum vertical ground reaction force and maximum vertical ground reaction force relative to body mass applied to the support leg during the kicks were also calculated with a force platform. The kicking motion was recorded using a three-dimensional motion-capture system. Maximum velocity of the ball, maximum linear velocity of the toe, ankle, knee and hip, and linear velocity of the toe at ball contact during the kicks were calculated. Non-significant differences were found in the parameters measured during the countermovement jump and the maximal instep soccer kick test before and after running, suggesting that the jumping and kicking performances of top-class young soccer players were not significantly affected after 20 min treadmill running at 80% of their individual maximum heart rate.

Influencia de la información termográfica infrarroja en el protocolo de prevención de lesiones de un equipo de fútbol profesional español

El fútbol es un deporte en cuya práctica existe una alta incidencia de lesión. Además, en el ámbito profesional las lesiones suponen un duro proceso de recuperación para el futbolista, una reducción del rendimiento deportivo para éste y para el equipo, y unos grandes costes económicos para el club. Dentro de esta problemática, la bibliografía consultada concluye que en las pretemporadas se produce una mayor incidencia de lesión por sobrecarga, es decir, sin contacto; un tipo de lesiones que está a nuestro alcance poder prevenir. Por ello, consideramos importante el conocer y desarrollar métodos, herramientas y principios para obtener programas preventivos efectivos, que reduzcan las elevadas cifras de incidencia de lesión mostradas por la literatura. El presente estudio observa y registra las lesiones, a través del cuestionario F-MARC, de un equipo profesional de fútbol de la Liga Española durante las pretemporadas 2008 (n=24) y 2009 (n=24). Además, durante la pretemporada 2009 se aplicó la termografía infrarroja para adquirir información sobre la asimilación de la carga de entrenamiento por parte de los jugadores, y dicha información se utilizarón para mejorar las tomas de decisiones de protocolos post-ejercicio específicos en prevención de lesiones, los cuales fueron los mismos que se utilizaron previamente en la pretemporada 2008. El estudio tiene un diseño con características pre-post sin grupo de control. Es un estudio longitudinal donde, tras un registro inicial de lesiones en la pretemporada 2008, los sujetos fueron expuestos a la variable independiente, utilización de la termografía infrarroja, en el protocolo de prevención de lesiones durante la pretemporada 2009. Los resultados de este trabajo muestran una reducción significativa de hasta el 60% en la frecuencia de lesión durante la pretemporada 2009, y un descenso de la incidencia de lesión total que pasa de 8,3 lesiones por cada 1000 horas de exposición en 2008 a 3,4 en 2009. Con ello, la probabilidad de lesión se redujo considerablemente pasando de un 85% de los jugadores lesionados en 2008 a un 26% en 2009; además, las lesiones de carácter muscular descendieron en 2009 un 70% con respecto al 2008, y los días de baja que causaron todas las lesiones pasó a reducirse un 91,8% en la pretemporada 2009. Por otro lado, el perfil térmico de los jugadores en función de su lateralidad y dominancia, guarda una gran similitud en sus temperaturas, tanto medias como máximas, con temperaturas más elevadas en la zona corporal lumbar y poplítea, y con temperaturas más bajas en tobillos y rodillas. Todas las zonas corporales estudiadas, exceptuando el tobillo (p<0,05), no presentan diferencias significativas entre ambos hemicuerpos, estableciendo un promedio de diferencia entre ambos lados de 0,06±0,16 ºC. Teniendo en cuenta estos resultados, consideramos el límite superior de normalidad de asimetría térmica bilateral en 0,3ºC para todas las zonas corporales estudiadas del miembro inferior exceptuando los tobillos. El parámetro ambiental que más relación tiene con la temperatura registrada por la cámara termográfica es la temperatura de la sala con un coeficiente de correlación cercano a r=1,00, seguido de la presión atmosférica con un coeficiente de correlación cercano r=0,50, y, por último, la humedad que no guarda ningún tipo de relación con la temperatura registrada en cada zona corporal en el rango de valores considerados en el estudio. Por otro lado, los resultados del ANOVA de un factor nos indican que existen diferencias de medias entre los tres grupos formados de temperatura ambiente de sala (1º=18º-21ºC, 2º=22º-24ºC y 3º=25º-31ºC). Además, los resultados de la prueba HSD de Tukey nos indican que existen diferencias entre cada uno de los grupos en todas las zonas corporales estudiadas exceptuando los tobillos. Por último, se propone la ecuación; TC-estándar = TC-real – [0,184 * (TS – 21ºC)] para predecir la influencia de la temperatura ambiente sobre la temperatura registrada por la cámara termográfica. Para concluir, tras los resultados obtenidos, podemos afirmar que la aplicación de un protocolo post-ejercicio de prevención de lesiones basado en la información adquirida a través de valoraciones con termografía infrarroja reduce la incidencia de lesión en el grupo de futbolistas profesionales estudiado. Tenemos que ser conscientes que nos encontramos ante un estudio de campo, donde existen muchos factores que han podido influenciar en los resultados y que son difíciles de controlar. Por lo tanto, debemos ser cautos y concluir que la información adquirida de las evaluaciones termográficas ha sido uno de los aspectos que ayudó a la reducción significativa de la incidencia de lesión en la pretemporada 2009 en el equipo de fútbol profesional español de este estudio, pero que seguramente hayan podido existir otros factores que también hayan favorecido este hecho. ABSTRACT Soccer is a sport with a high incidence of injury. Moreover, in professional soccer injuries lead to a tough recovery process for the players, a reduction athletic performance for them and for their teams, and large economic costs for the club. In this issue, the literature concludes that in the preseason a greater incidence of overuse injury occurs (ie, without contact), and this is a type of injury that we can prevent. Therefore, we consider that it is important to know and develop methods, tools and principles to obtain effective preventive programs that reduce the high injury incidence figures shown in the literature. This study observed and recorded injuries, through the questionnaire F-MARC, from a professional soccer team in the Spanish league during the preseason 2008 (n = 24) and 2009 (n = 24). Moreover, during the 2009 preseason infrared thermography was applied to acquire information about the assimilation of the training load by the players, and this information was used to improve the decision making in the specific post-exercise injury prevention protocols, which were the same used in the previous season 2008. The study had a pre-post design without control group. Is a longitudinal study where, after an initial registration of injuries in the 2008 preseason, subjects were exposed to the independent variable, using infrared thermography, included in the protocol for injury prevention during the 2009 preseason. The results of this study show a significant reduction of up to 60% in the frequency of injury during the 2009 preseason, and a decrease in total injury incidence passing from 8.3 injuries per 1000 hours of exposure in 2008 to 3.4 in 2008. With this, the likelihood of injury decreased significantly from 85% of the players injuried in 2008 to 26% in 2009, also muscle injuries in 2009 fell 70% compared to 2008, and sick leave days that caused by all the injuries happened were reduced a 91.8% in the 2009 preseason. On the other hand, the thermal profile of the players according to their laterality and dominance, is quiet similar in their temperatures, both average and maximum values, with an estimated average of the highest temperatures in the lower back and popliteal areas in the back areas, and lower temperatures in the ankles and knees. All body areas studied, except for the ankle (p <0.05), had no significant differences between both sides of the body, establishing an average difference between both sides of 0.06 ± 0.16 °C. Given these results, we consider the upper limit of normal bilateral thermal asymmetry 0.3 °C for all body areas studied in the lower limb except for ankles. The environmental parameter higher related with temperature recorded by the camera is the temperature of the room with a correlation coefficient close to r = 1.00, followed by atmospheric pressure with a correlation coefficient near r = 0.50, and finally, the humidity that, in the range of values considered in the study, it is not related with temperature in each body area. On the other hand, the results of one-way ANOVA indicate that there are differences between the three temperature of the room groups (1 ° = 18-21 °C, 2 º = 22-24 ºC and 3 º = 25-31 ºC). Moreover, the results of the Tukey HSD test indicate that there are differences between each of the groups for all body areas studied except the ankles. Finally, we propose the equation TC-standard = TC-real – [0,184 * (TS – 21ºC)] to predict the influence of temperature on the temperature recorded by the thermographic camera. In conclusion, we can say from our results that the implementation of a post-exercise injury prevention protocol based on information from assessments with infrared thermography reduces the incidence of injury in professional soccer players. We must be aware that we are facing a field study, where there are many factors that could influence the results and they are difficult to control. Therefore, we must be cautious and conclude that the information acquired from the thermographic evaluation has been one of the aspects that helped to significantly reduce the incidence of injury in the preseason 2009 in the Spanish professional football team, but probably they could exist other factors with a positive effect on the reduction of the injury rates.

Análisis de la marcha: evaluación de un exoesqueleto aplicado a la marcha asistida

La marcha humana es el mecanismo de locomoción por el cual el cuerpo humano se traslada en línea recta gracias a una serie de movimientos coordinados de la pelvis y de las articulaciones del miembro inferior. Frecuentemente se encuentra influenciada por factores biomecánicos, anatómicos o patologías del sistema neuromusculoesquelético que modifican la forma de caminar de cada individuo. La lesión de médula espinal es una de las patologías que afectan el desarrollo normal de los patrones de la marcha por alteración de la movilidad, de la sensibilidad o del sistema nervioso autónomo. Aunque la lesión medular afecta otras funciones, además de la pérdida de función motora y sensorial, la recuperación de la capacidad de caminar es la mayor prioridad identificada por los pacientes durante la rehabilitación. Por ello, el desarrollo de dispositivos que faciliten la rehabilitación o compensación de la marcha es uno de los principales objetivos de diferentes grupos de investigación y empresas. En el contexto del proyecto Hybrid Technological Platform for Rehabilitation, Functional Compensation and Training of Gait in Spinal Cord Injury Patients se ha desarrollado un dispositivo que combina una órtesis activa (exoesqueleto) y un andador motorizado. Este sistema, como otros dispositivos, tiene el movimiento humano como estándar de referencia, no obstante no se evalúa de manera habitual, cómo es el patrón de la marcha reproducido y su similitud o diferencias con la marcha humana, o las modificaciones o adaptaciones en la interacción con el cuerpo del paciente. El presente estudio trata de examinar las características de la marcha normal en diversos grupos de población, y las diferencias con el patrón de marcha lenta. Finalmente, se pretende evaluar qué modificaciones y adaptaciones sufre el patrón de marcha lenta teórico al ser reproducido por el exoesqueleto. La presente investigación consiste en un estudio cuantitativo transversal desarrollado en dos etapas: estudio 1 y estudio 2. En el estudio 1 se analizó el patrón de la marcha a velocidad libremente seleccionada (normal) y el patrón de la marcha a velocidad lenta (0.25m/s) en 62 sujetos distribuidos en grupos considerando el sexo y los percentiles 25, 50 y 75 de estatura de la población española. Durante el estudio 2 se analizó el patrón de la marcha lenta reproducido por el dispositivo Hybrid a diferentes porcentajes de peso corporal (30%, 50% y 70%) en diez sujetos seleccionados aleatoriamente de la muestra del estudio 1. En ambos estudios se obtuvieron variables espacio-temporales y cinemáticas mediante un sistema de captura de movimiento con 6 cámaras distribuidas a lo largo de un pasillo de marcha. Se calcularon las medias, las desviaciones estándar y el 95% de intervalo de confianza, y el nivel alfa de significación se estableció en α=0.05 para todas las pruebas estadísticas. Las principales diferencias en el patrón normal de la marcha se encontraron en los parámetros cinemáticos de hombres y mujeres, aunque también se presentaron diferencias entre los grupos en función de la estatura. Las mujeres mostraron mayor flexión de cadera y rodilla, y mayor extensión de tobillo que los hombres durante el ciclo normal, aunque la basculación lateral de la pelvis, mayor en las mujeres, y el desplazamiento lateral del centro de gravedad, mayor en los hombres, fueron los parámetros identificados como principales discriminantes entre sexos. La disminución de la velocidad de la marcha mostró similares adaptaciones y modificaciones en hombres y en mujeres, presentándose un aumento de la fase de apoyo y una disminución de la fase de oscilación, un retraso de los máximos y mínimos de flexoextensión de cadera, rodilla y tobillo, y una disminución del rango articular en las tres articulaciones. Asimismo, la basculación lateral de la pelvis y el movimiento vertical del centro de gravedad disminuyeron, mientras que el movimiento lateral del centro de gravedad y el ancho de paso aumentaron. Durante la evaluación del patrón de la marcha reproducido por el exoesqueleto se observó que las tres articulaciones del miembro inferior disminuían el rango de movimiento por la falta de fuerza de los motores para contrarrestar el peso corporal, incluso con un 70% de descarga de peso. Además, la transferencia de peso se encontró limitada por la falta de movimiento de la pelvis en el plano frontal y se sustituyó por un aumento de la inclinación del tronco y, por tanto, del movimiento lateral del centro de gravedad. Este hecho, junto al aumento del desplazamiento vertical del centro de gravedad, hizo del patrón de la marcha reproducido por el exoesqueleto un movimiento poco eficiente. En conclusión, se establecen patrones de marcha normal diferenciados por sexos, siendo la basculación lateral de la pelvis y el movimiento lateral del centro de gravedad los parámetros discriminantes más característicos entre sexos. Comparando la marcha a velocidad libremente seleccionada y la velocidad lenta, se concluye que ambos sexos utilizan estrategias similares para adaptar el patrón de la marcha a una velocidad lenta y se mantienen las características diferenciadoras entre hombres y mujeres. En relación a la evaluación del dispositivo Hybrid, se deduce que la falta de movimiento lateral de la pelvis condiciona la transferencia de peso y el aumento del rango de movimiento del centro de gravedad y, en consecuencia, tiene como resultado un patrón de la marcha poco eficiente. Este patrón no resultaría indicado para los procesos de rehabilitación o recuperación de la marcha, aunque podría considerarse adecuado para la compensación funcional de la bipedestación y la locomoción. ABSTRACT The human walking is a means of moving body forward using a repetitious and coordinated sequence of pelvis and lower limb motions. It is frequently influenced by biomechanical and anatomical factors or by musculoskeletal pathologies which modify the way of walking. The spinal injury is one of those pathologies which affect the normal pattern of walking, due to the alteration of the mobility, the sensory or the autonomic nervous system. Although the spinal injury affects many other body functions, apart from the motor and sensory ones, the main priority for patients is to recover the ability of walking. Consequently, the main objective of many research groups and private companies is the development of rehabilitation and compensation devices for walking. In this context, the Hybrid Technological Platform for Rehabilitation, Functional Compensation and Training of Gait in Spinal Cord Injury Patients project has developed a device which integrates an exoskeleton and a motorized smart walker. This system, as other similar devices, has the human movement as standard reference. Nevertheless, these devices are not usually evaluated on the way they reproduce the normal human pattern or on the modifications and in the interactions with the patient’s body. The aim of the present study is to examine the normal walking characteristics, to analyze the differences between self-selected and low speed walking patterns, and to evaluate the modifications and adaptations of walking pattern when it is reproduced by the exoskeleton. The present research is a quantitative cross-sectional study carried out in two phases: study 1 and study 2. During the study 1, the self-selected and the low speed (0.25m/s) walking patterns were analyzed in sixty-two people distributed in groups, according to sex and 25th, 50th and 75th percentiles of height for Spanish population. The study 2 analyzed the low speed walking pattern reproduced by the Hybrid system in three conditions: 30%, 50% and 70% of body weight support. To do this, ten subjects were randomly selected and analyzed from the people of study 1. An optoelectronic system with six cameras was used to obtain spatial, temporal and kinematic parameters in both studies. Means, standard deviations and 95% confidence intervals of the study were calculated. The alpha level of significance was set at α=0.05 for all statistical tests. The main differences in normal gait pattern were found in kinematic parameters between men and women. The hip and the knee were more flexed and the ankle plantar flexion was higher in women than in men during normal gait cycle. Although the greater pelvic obliquity of women and the higher lateral movement of center of gravity of men were the most relevant discriminators between male and female gait patterns. Comparing self-selected and low speed walking patterns, both sexes showed similar adaptations and modifications. At low speed walking, men and women increased the stance phase ratio and decreased the swing phase ratio. The maximum and minimum peak flexion of hip, knee and ankle appeared after and the range of motion of them decreased during low speed walking. Furthermore, the pelvic obliquity and the vertical movement of the center of gravity decreased, whereas the lateral movement of center of gravity and step width increased. Evaluating the gait pattern reproduced by the exoskeleton, a decrease of lower limb range of motion was observed. This was probably due to the lack of strength of the engines, which were not able to control the body weight, even with the 70% supported. Moreover, the weight transfer from one limb to the contralateral side was restricted due to the lack of pelvis obliquity. This movement deficiency was replaced by the lateral torso sway and, consequently, the increase of lateral movement of the center of gravity. This fact, as well as the increase of the vertical displacement of the center of gravity, made inefficient the gait pattern reproduced by the exoskeleton. In conclusion, different gait patterns of both sexes have been determined, being pelvis obliquity and lateral movement of center of gravity the most relevant discriminators between male and female gait patterns. Comparing self-selected and low speed walking patterns, it was concluded that both sexes use similar strategies for adapting the gait pattern to a low speed, and therefore, the differentiating characteristics of normal gait are maintained. Regarding the Hybrid system evaluation, it was determined that the gait pattern reproduced by the exoskeleton is inefficient. This was due to the lack of pelvis obliquity and the increase of the center of gravity displacement. Consequently, whereas the walking pattern reproduced by the exoskeleton would not be appropriated for the rehabilitation process, it could be considered suitable for functional compensation of walking and standing.

Low dimensionality of supraspinally induced force fields

Recent experiments using electrical and N-methyl-d-aspartate microstimulation of the spinal cord gray matter and cutaneous stimulation of the hindlimb of spinalized frogs have provided evidence for a modular organization of the frog’s spinal cord circuitry. A “module” is a functional unit in the spinal cord circuitry that generates a specific motor output by imposing a specific pattern of muscle activation. The output of a module can be characterized as a force field: the collection of the isometric forces generated at the ankle over different locations in the leg’s workspace. Different modules can be combined independently so that their force fields linearly sum. The goal of this study was to ascertain whether the force fields generated by the activation of supraspinal structures could result from combinations of a small number of modules. We recorded a set of force fields generated by the electrical stimulation of the vestibular nerve in seven frogs, and we performed a principal component analysis to study the dimensionality of this set. We found that 94% of the total variation of the data is explained by the first five principal components, a result that indicates that the dimensionality of the set of fields evoked by vestibular stimulation is low. This result is compatible with the hypothesis that vestibular fields are generated by combinations of a small number of spinal modules.

Suppression of experimental arthritis by gene transfer of interleukin 1 receptor antagonist cDNA.

Restoration of the impaired balance between pro- and antiinflammatory cytokines should provide effective treatment of rheumatoid arthritis. Gene therapy has been proposed as an approach for delivery of therapeutic proteins to arthritic joints. Here, we examined the efficacy of antiinflammatory gene therapy in bacterial cell wall-induced arthritis in rats. Human secreted interleukin 1 receptor antagonist (sIL-1ra) was expressed in joints of rats with recurrent bacterial cell wall-induced arthritis by using ex vivo gene transfer. To achieve this, primary synoviocytes were transduced in culture with a retroviral vector carrying the sIL-1ra cDNA. Transduced cells were engrafted in ankle joints of animals prior to reactivation of arthritis. Animals in control groups were engrafted with synoviocytes transduced with lacZ and neo marker genes. Cells continued to express transferred genes for at least 9 days after engraftment. We found that gene transfer of sIL-1ra significantly suppressed the severity of recurrence of arthritis, as assessed by measuring joint swelling and by the gross-observation score, and attenuated but did not abolish erosion of cartilage and bone. The effect of intraarticularly expressed sIL-1ra was essentially local, as there was no significant difference in severity of recurrence between unengrafted contralateral joints in control and experimental groups. We estimate that locally expressed sIL-1ra was about four orders of magnitude more therapeutically efficient than systemically administered recombinant sIL-1ra protein. These findings provide experimental evidence for the feasibility of antiinflammatory gene therapy for arthritis.

Pré-condicionamento isquêmico remoto em portadores de claudicação intermitente de membros inferiores

INTRODUÇÃO: Pré-condicionamento isquêmico remoto (PCIR) é o fenômeno pelo qual curtos períodos de isquemia sub-letal sobre um órgão ou tecido, intercalados com reperfusão do mesmo, conferem a outros órgãos ou tecidos distantes deste, um aumento na capacidade da resistir a episódios subsequentes de isquemia, a qual os mesmos possam ser expostos. Com base nesse fato, testamos a hipótese de que o pré-condicionamento isquêmico remoto em pacientes portadores de claudicação intermitente de membros inferiores poderia aumentar a capacidade de deambulação desses pacientes, extrapolando o conceito do PCIR de aumento da capacidade de preservação da integridade celular frente à isquemia, para a manutenção da função celular, tornando a célula mais apta ao trabalho em situações de privação de oxigênio, geradas pela restrição do fluxo sanguíneo, como ocorre nos pacientes com claudicação intermitente de membros inferiores, durante o exercício. OBJETIVOS: Avaliar se o PCIR aumenta a distância de início de claudicação e/ou a distância total de claudicação em pacientes com doença arterial obstrutiva periférica. MÉTODOS: Foram estudados 52 pacientes ambulatoriais que apresentavam queixa de claudicação intermitente dos membros inferiores, associada a um pulso arterial ausente ou reduzido no membro sintomático e/ou um índice tornozelo-braço <0,90. Estes pacientes foram randomizados em três grupos (A, B e C). Todos os pacientes foram submetidos a dois testes de caminhada em esteira de acordo com o protocolo de Gardner. O grupo A fez o primeiro teste de esteira sem o pré-condicionamento isquêmico remoto e, após 7 dias, foi submetido a um novo teste de esteira, agora precedido pelo pré-condicionamento isquêmico remoto. O grupo B foi submetido ao pré-condicionamento isquêmico remoto antes do primeiro teste de esteira e, após 7 dias, realizou novo teste de esteira, agora sem o pré-condicionamento isquêmico remoto. Já no Grupo C (grupo controle), ambos os testes de esteira foram realizados sem pré-condicionamento isquêmico remoto, também com 7 dias de intervalo. RESULTADOS: Os grupos A e C mostraram um aumento na distância de início de claudicação, no segundo teste, em comparação com o primeiro teste. O grupo A teve um aumento estatisticamente significativo, em relação ao grupo C (grupo controle). Com relação à distância total de claudicação, todos os grupos (A, B e C), mostraram um aumento estatisticamente significativo a favor do segundo teste, porém não foi observada diferença entre os grupos (A, B e C). CONCLUSÕES: O pré-condicionamento isquêmico remoto aumentou a distância inicial de claudicação em pacientes com claudicação intermitente, no entanto, ele não afetou a distância total de claudicação dos pacientes portadores de claudicação intermitente de membros inferiores