Preliminary study of elastic-tension digital neoprene orthoses for proximal interphalangeal joint flexion contracture.

Flexion contracture of the proximal interphalangeal joint (PIPJ) is one of the most frequent complications in finger trauma. Orthoses are the most widely used method to optimize total end-range time (TERT). No previous studies showed that an elastic tension orthosis could be applied for longer than 12 h. We aimed to demonstrate that the elastic-tension digital neoprene orthosis (ETDNO) can achieve higher TERT and therefore better range of motion than other elastic-tension orthoses (ETO) described in the literature. A prospective study of treatment of PIPJ flexion contracture included 10 PIP joints in 8 patients who met the selection criteria. They were instructed to use the ETDNO for around 23 h per day as far as possible, during a period of 3 weeks. Patients reported a mean TERT of 20.6 h a day. PIPJ contracture improved by a mean Torque Range of Motion (TROM) of 23.5° at 500 g and 22.9° at 800 g of passive extension force during the 3-week treatment. Based on the results of this study, the ETDNO appears to offer a highly effective approach for improving PIPJ flexion contracture, increasing range of motion in extension. ETDNO's efficacy probably lies in the significantly improved comfort and low-profile design, enabling excellent compliance and thus optimizing TERT. LEVEL OF EVIDENCE: Level III.

Wrist kinetics after scaphoidectomy.

BACKGROUND: The scaphoid cannot be excised without generating substantial carpal dysfunction. The extent and nature of such a destabilizing procedure, however, has never been properly studied in the laboratory. METHODS: We used a six-degrees-of-freedom motion tracking device to quantify the changes in carpal alignment produced by isometric simultaneous loading of five wrist motor tendons in 12 fresh normal cadaver arms, before and after excising the entire scaphoid. FINDINGS: In the intact wrist, tendon loading consistently extended and supinated the capitate while flexing the triquetrum. After scaphoidectomy, the opposite rotations were always found: the capitate collapsed into flexion and pronation, whereas the triquetrum migrated proximally, while extending and radial deviating. All these changes were statistically significant. INTERPRETATION: Unless it is supplemented by some sort of midcarpal stabilization, scaphoidectomy alone is much too aggressive as a procedure to be considered a treatment option for wrist osteoarthritis. LEVEL OF EVIDENCE: Laboratory study. Not applicable.

Clasificación del patrón transversal de las fracturas de la cabeza del radio tipo Mason II y su utilidad en la osteosíntesis mediante técnica artroscópica. Estudio anatomoquirúrgico / Classification of the transverse pattern of Mason II radial head fractures and its usefulness in arthroscopic osteosynthesis. Anatomo-surgical study

Objetivo: La reducción y fijación de la fractura de la cabeza del radio tipo MasonII asistida por artroscopia es una técnica válida que proporciona buenos resultados. El objetivo de este estudio es llamar la atención sobre la utilidad de la localización de la fractura en la cabeza del radio en cuadrantes definidos con respecto a la tuberosidad bicipital mediante la TC. Ello ayudaría a planificar la posición del antebrazo óptima para acceder a cada cuadrante y prever las dificultades específicas de cada uno. Material y método: Se ha procedido a la disección de 4 especímenes de cadáver criopreservado. Hemos dividido la cabeza del radio en 4 cuadrantes con respecto a la tuberosidad bicipital objetivando el cambio de posición en pronación y en supinación máxima con respecto a la cavidad sigmoidea menor y a las estructuras neurovasculares. Resultados: La cabeza del radio se desplaza con la pronosupinación, por lo que existen áreas de convergencia entre los distintos cuadrantes. El cuadrante1 se aborda en supinación por un portal anteromedial. El cuadrante2 se aborda en pronación máxima mediante un portal lateral. El cuadrante3 se puede abordar a través de portales laterales, con el antebrazo en posición neutra y en pronación. El cuadrante4 es accesible con el antebrazo en posición neutra y en supinación a través de un portal lateral. Conclusiones: Según la localización de la fractura en la cabeza del radio con respecto a la tuberosidad bicipital, necesitaremos acceder por un portal artroscópico determinado, siendo los cuadrantes mediales (anteromedial y posteromedial) los más exigentes técnicamente

Objective: The management of MasonII fracture pattern assisted by arthroscopy is a valid technique that provides good results. The objective of this study was to draw attention to the usefulness of the location of the fracture in the head of the radius in defined quadrants with respect to the bicipital tuberosity through CT. This would help to plan the optimal forearm position to access each quadrant and foresee the specific difficulties of each one. Material and method: We dissected 4 specimens of cryopreserved cadaver. We divided the radial head into 4 quadrants with regard to the bicipital tuberosity, objectifying the change of position in pronation and maximum supination with respect to the sigmoid cavity and neurovascular structures. Results: The head of the radio moves with pronosupination, so there are areas of convergence between the different quadrants. Quadrant1 is approached in supination via an anteromedial portal. Quadrant2 is approached in maximum pronation through a lateral portal. Quadrant3 can be approached through lateral portals, with the forearm in neutral position and in pronation. Quadrant4 is accessible with the forearm in a neutral position and in supination through a lateral portal. Conclusions: Depending on the location of the fracture in the head of the radius with respect to the bicipital tuberosity, we will need access through a specific arthroscopic portal, with the medial quadrants (anteromedial and posteromedial) being the most technically demanding

Classification of the transverse pattern of Mason II radial head fractures and its usefulness in arthroscopic osteosynthesis. Anatomo-surgical study. / Clasificación del patrón transversal de las fracturas de la cabeza del radio tipo Mason II y su utilidad en la osteosíntesis mediante técnica artroscópica. Estudio anatomoquirúrgico.

OBJECTIVE: The management of MasonII fracture pattern assisted by arthroscopy is a valid technique that provides good results. The objective of this study was to draw attention to the usefulness of the location of the fracture in the head of the radius in defined quadrants with respect to the bicipital tuberosity through CT. This would help to plan the optimal forearm position to access each quadrant and foresee the specific difficulties of each one. MATERIAL AND METHOD: We dissected 4 specimens of cryopreserved cadaver. We divided the radial head into 4 quadrants with regard to the bicipital tuberosity, objectifying the change of position in pronation and maximum supination with respect to the sigmoid cavity and neurovascular structures. RESULTS: The head of the radio moves with pronosupination, so there are areas of convergence between the different quadrants. Quadrant1 is approached in supination via an anteromedial portal. Quadrant2 is approached in maximum pronation through a lateral portal. Quadrant3 can be approached through lateral portals, with the forearm in neutral position and in pronation. Quadrant4 is accessible with the forearm in a neutral position and in supination through a lateral portal. CONCLUSIONS: Depending on the location of the fracture in the head of the radius with respect to the bicipital tuberosity, we will need access through a specific arthroscopic portal, with the medial quadrants (anteromedial and posteromedial) being the most technically demanding.

Infecciones necrosantes de partes blandas atendidas en un servicio de urgencias de tercer nivel: evolución y correlación con la escala laboratory risk indicator for necrotizing fasciitis (LRINEC) / Necrotizing fasciitis attended in the Emergency Department in a tertiary Hospital: evaluation of the LRINEC scale

Objetivo. Describir la mortalidad y las complicaciones de pacientes atendidos en urgencias, con diagnóstico de infección necrosante de partes blandas (INPB) y su correlación con la escala Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC). Método. Estudio observacional retrospectivo con inclusión de pacientes con diagnóstico de INPB en urgencias de un hospital terciario durante 7 años. Los resultados se muestran como mediana, rango intercuartílico y rango absoluto para las variables cuantitativas. En el caso de las variables cualitativas, como frecuencias absoluta y relativa. La comparación se ha llevado a cabo mediante comparación post-hoc a partir de un análisis ANOVA con aproximación no paramétrica. Las comparaciones entre grupos de LRINEC en las variables cualitativas se han realizado con la prueba exacta de Fisher. Resultados. Se identificaron 24 pacientes con edad media de 51,9 años. La escala LRINEC se determinó en 21 pacientes: en 10 indicó bajo riesgo (<6), en 4 riesgo intermedio (6 o 7) y en 7 alto riesgo (≥8). La tasa de amputación en riesgos bajo, intermedio y alto fue del 10, 25 y 66%, respectivamente, con una mortalidad del 4,2%. Se observa un aumento en la estancia hospitalaria entre los niveles bajo y alto de la escala (p=0,007). Conclusiones. En general no se ha podido constatar un cambio en el pronóstico entre los niveles medio y alto de la escala LRINEC. Pero sí entre la estancia hospitalaria entre el nivel bajo y el alto, triplicando prácticamente la mediana de días de estancia hospitalaria (AU)

Aim. To describe mortality and complications of patients seen in the emergency room, diagnosed with necrotizing soft tissue infection (NSTI) and the correlation of such complications with the Laboratory Risk Indicator for Necrotizing fasciitis scale (LRINEC). Methods. Retrospective observational study including patients with a diagnosis of NSTI in the emergency room of a tertiary hospital over 7 years. The results are shown as median, interquartile range and absolute range for quantitative variables. In the case of qualitative variables, the results are shown as absolute and relative frequency. The comparison between the categories of the LRINEC scale was performed through a post-hoc comparison from a non-parametric ANOVA analysis. Comparisons between LRINEC groups in the qualitative variables were performed using Fisher's Exact test. Results. 24 patients with a mean age of 51.9 years were identified. The LRINEC scale was used on 21 patients: in 10, the value indicated low risk (<6), in 4 it indicated intermediate risk (6 or 7) and in 7 it indicated high risk (≥8). The amputation rate in patients with low, intermediate and high risk was 10%, 25% and 66% respectively with a mortality of 4.2%. There was an increase in hospital stay between the low and high level of the scale (p=0,007). Conclusions. In general, a change in the prognosis between the medium and high levels of the LRINEC scale could not be recorded, but was recorded in hospital stay between the low and the high level, practically tripling the median of days of hospital stay (AU)

El neuroma de la porción distal del nervio interóseo posterior como causa de dolor dorsal persistente de muñeca / Neuroma of the distal posterior interosseous nerve as a cause of persistent dorsal wrist pain

El dolor en el dorso de la muñeca es una causa frecuente de consulta médica en nuestra práctica clínica habitual. Normalmente este dolor puede ser debido a procesos traumáticos, inflamatorios o degenerativos. Pero en ocasiones el origen del dolor se aleja de estas causas frecuentes. Presentamos un caso de dolor crónico al nivel dorsal de muñeca sin claro antecedente traumático ni componente degenerativo o inflamatorio atribuible. Siendo de etiología neuropática, debido a un neuroma del nervio interóseo posterior precapsular. Se discuten posibles causas, métodos de diagnóstico y opciones de tratamiento (AU)

Dorsal wrist pain is a very common cause of complaint in the clinical practice of the hand surgeon. Such pain can frequently be related to traumatic, inflammatory or degenerative diseases, but sometimes its origin is far away from these common causes. A rare case is reported of chronic dorsal wrist pain of neuropathic origin, due to a pre-capsular neuroma of the posterior interosseous nerve. Possible causes, diagnostic hints, and treatment options are thoroughly discussed (AU)

Necrotizing fasciitis attended in the Emergency Department in a tertiary Hospital: Evaluation of the LRINEC scale. / Infecciones necrosantes de partes blandas atendidas en un servicio de urgencias de tercer nivel: evolución y correlación con la escala laboratory risk indicator for necrotizing fasciitis (LRINEC).

AIM: To describe mortality and complications of patients seen in the emergency room, diagnosed with necrotizing soft tissue infection (NSTI) and the correlation of such complications with the Laboratory Risk Indicator for Necrotizing fasciitis scale (LRINEC). METHODS: Retrospective observational study including patients with a diagnosis of NSTI in the emergency room of a tertiary hospital over 7 years. The results are shown as median, interquartile range and absolute range for quantitative variables. In the case of qualitative variables, the results are shown as absolute and relative frequency. The comparison between the categories of the LRINEC scale was performed through a post-hoc comparison from a non-parametric ANOVA analysis. Comparisons between LRINEC groups in the qualitative variables were performed using Fisher's Exact test. RESULTS: 24 patients with a mean age of 51.9 years were identified. The LRINEC scale was used on 21 patients: in 10, the value indicated low risk (<6), in 4 it indicated intermediate risk (6 or 7) and in 7 it indicated high risk (≥8). The amputation rate in patients with low, intermediate and high risk was 10%, 25% and 66% respectively with a mortality of 4.2%. There was an increase in hospital stay between the low and high level of the scale (p=0,007). CONCLUSIONS: In general, a change in the prognosis between the medium and high levels of the LRINEC scale could not be recorded, but was recorded in hospital stay between the low and the high level, practically tripling the median of days of hospital stay.

Abordaje anterior limitado del codo para la reducción abierta y fijación interna de las fracturas del capitellum. Técnica quirúrgica y experiencia clínica en 2casos con más de 2 años de seguimiento / The limited anterior approach of the elbow for open reduction and internal fixation of capitellum fractures. Surgical technique and clinical experience in 2 cases with more than 2 years follow-up

Objetivo. Las fracturas que afectan al capitellum pueden ser tratadas quirúrgicamente mediante escisión del fragmento, o mediante reducción y fijación interna con tornillos con o sin cabeza. El abordaje lateral de Kocher es el más usado para la reducción abierta. Creemos que el abordaje anterior limitado del codo podría ser una opción válida para tratar este tipo de fracturas, ya que no implica la desinserción de ningún grupo muscular ni de ningún ligamento y facilita la colocación anteroposterior de los tornillos, que ha demostrado ser biomecánicamente superior. Material y método. Describimos la técnica quirúrgica y evaluamos los resultados en 2casos clínicos con una fractura de tipo 1 de Bryan y Morrey (tipo 1A de Dubberley) mediante evolución clínica y radiológica. Dos cuestionarios diferentes sobre calidad de vida fueron realizados por teléfono: el EuroQol Five Dimensions Questionnaire (EQ-5D) y la porción contestada por el paciente del Liverpool Elbow Score (PAQ-LES). Resultados. Los 2pacientes presentaron una evolución clínica favorable a los 36 y 24 meses, respectivamente con un arco de movimiento de extensión/flexión de −5°/145° y −10°/145°, así como una pronosupinación de 85°/80° y de 90°/90°. Los 2pacientes presentaron consolidación radiológica sin signos de osteonecrosis, con el EQ-5D de 0,857 y 0,910 (rango: 0,36-1) y el PAQ-LES de 35 y 35 (rango: 17-36), respectivamente. Conclusiones. Creemos que el abordaje anterior limitado del codo es una opción técnica que tener en cuenta en caso de decidirse un tratamiento quirúrgico abierto de una fractura de capitellum, si bien necesitamos de estudios posteriores que demuestren su superioridad y seguridad clínica con respecto al abordaje clásico lateral de Kocher (AU)

Objective. Fractures involving the capitellum can be treated surgically by excision of the fragment, or by reduction and internal fixation with screws, with or without heads. The lateral Kocher approach is the most common approach for open reduction. We believe that the limited anterior approach of the elbow, could be a valid technique for treating these fractures, as it does not involve the detachment of any muscle group or ligament, facilitating the recovery process. Material and method. A description is presented of the surgical technique, as well as of 2cases with a Bryan-Morrey type 1 fracture (Dubberley type 1A). Two different final quality of life evaluation questionnaires were completed by telephone: the EuroQol Five Dimensions Questionnaire (EQ-5D), and the patient part of the Liverpool Elbow Score (PAQ-LES) questionnaire. Results. The 2patients showed favourable clinical progress at 36 and 24 months, respectively, with an extension/flexion movement arc of −5°/145° and −10°/145°, as well as a pronosupination of 85°/80° and 90°/90°. The 2patients showed radiological consolidation with no signs of osteonecrosis. The EQ-5D score was 0.857 and 0.910 (range: 0.36-1), and a PAQ-SLE of 35 and 35 (range: 17-36), respectively. Conclusions. We believe that the limited anterior approach of the elbow is a technical option to consider for the open surgical treatment of a capitellum fracture, although further studies are needed to demonstrate its superiority and clinical safety compared to the classical lateral Kocher approach (AU)

The limited anterior approach of the elbow for open reduction and internal fixation of capitellum fractures. Surgical technique and clinical experience in 2 cases with more than 2 years follow-up. / Abordaje anterior limitado del codo para la reducción abierta y fijación interna de las fracturas del capitellum. Técnica quirúrgica y experiencia clínica en 2casos con más de 2 años de seguimiento.

OBJECTIVE: Fractures involving the capitellum can be treated surgically by excision of the fragment, or by reduction and internal fixation with screws, with or without heads. The lateral Kocher approach is the most common approach for open reduction. We believe that the limited anterior approach of the elbow, could be a valid technique for treating these fractures, as it does not involve the detachment of any muscle group or ligament, facilitating the recovery process. MATERIAL AND METHOD: A description is presented of the surgical technique, as well as of 2cases with a Bryan-Morrey type 1 fracture (Dubberley type 1A). Two different final quality of life evaluation questionnaires were completed by telephone: the EuroQol Five Dimensions Questionnaire (EQ-5D), and the patient part of the Liverpool Elbow Score (PAQ-LES) questionnaire. RESULTS: The 2patients showed favourable clinical progress at 36 and 24 months, respectively, with an extension/flexion movement arc of -5°/145° and -10°/145°, as well as a pronosupination of 85°/80° and 90°/90°. The 2patients showed radiological consolidation with no signs of osteonecrosis. The EQ-5D score was 0.857 and 0.910 (range: 0.36-1), and a PAQ-SLE of 35 and 35 (range: 17-36), respectively. CONCLUSIONS: We believe that the limited anterior approach of the elbow is a technical option to consider for the open surgical treatment of a capitellum fracture, although further studies are needed to demonstrate its superiority and clinical safety compared to the classical lateral Kocher approach.

Neuroma of the distal posterior interosseous nerve as a cause of persistent dorsal wrist pain. / El neuroma de la porción distal del nervio interóseo posterior como causa de dolor dorsal persistente de muñeca.

Dorsal wrist pain is a very common cause of complaint in the clinical practice of the hand surgeon. Such pain can frequently be related to traumatic, inflammatory or degenerative diseases, but sometimes its origin is far away from these common causes. A rare case is reported of chronic dorsal wrist pain of neuropathic origin, due to a pre-capsular neuroma of the posterior interosseous nerve. Possible causes, diagnostic hints, and treatment options are thoroughly discussed.

Control muscular de la inestabilidad escafolunar. Estudio experimental / Muscular control of scapholunate instability. An experimental study

Objetivo. El uso del cemento óseo esta muy extendido en COT, existiendo multitud de estudios experimentales que lo avalan. La mayoría de los ensayos mecánicos están realizados en seco, lo que cuestiona la extrapolación de los resultados a la clínica. El objetivo de este estudio es evaluar si las propiedades mecánicas del polimetilmetacrilato (PMMA) obtenidas en series previas en seco, se mantienen en un medio fisiológico. Material y método. Se ha diseñado un estudio experimental para evaluar este aspecto, utilizando PMMA con antibiótico (vancomicina). Cuatro grupos fueron definidos en función del medio estudiado (seco o líquido) y de la realización de un acondicionamiento previo en suero fisiológico (una semana o un mes). Se hicieron estudios de desgaste y resistencia a flexión según las normativas ISO y ASTM, valorando el desgaste, el coeficiente de fricción, la resistencia a la rotura y el modulo de Young. Las muestras fueron analizadas mediante microscopía electrónica. Resultados. Las muestras ensayadas en medio líquido presentaron menores valores de desgaste, así como menor resistencia a flexión, obteniéndose significación en el desgaste. El tipo de desgaste se modificó de un desgaste abrasivo a uno adhesivo en aquellas muestras estudiadas en medio líquido. El tiempo de acondicionamiento proporcionó menores valores de desgaste (p < 0,05). Conclusiones. Se recomienda precaución a la hora de extrapolar los resultados de los estudios sobre PMMA en seco dado el diferente comportamiento mecánico del cemento en un medio líquido mucho más cercano a la situación clínica real, como es el suero fisiológico (AU)

Purpose. The use of bone cement is widespread in orthopaedic surgery. Most of the mechanical tests are performed in dry medium, making it difficult to extrapolate the results. The objective of this study is to assess if the mechanical properties of polymethylmethacrylate (PMMA), obtained in previous reports, are still present in a liquid medium. Material and method. An experimental study was designed with antibiotic (vancomycin) loaded PMMA. Four groups were defined according to the medium (dry or liquid) and the pre-conditioning in liquid medium (one week or one month). Wear and flexural strength tests were performed according to ASTM and ISO standards. Volumetric wear, friction coefficient, tensile strength, and Young's modulus were analyzed. All samples were examined by scanning electron microscopy (AU)

[Muscular control of scapholunate instability. An experimental study]. / Control muscular de la inestabilidad escafolunar. Estudio experimental.

PURPOSE: As long as the neuromuscular stabilizers are intact, a lesion of the scapholunate ligament may or may not progress to a carpal instability. The mechanisms by which the muscles compensate this defect are not very well known. We designed an experimental study with the aim of clarifying these mechanisms. MATERIAL AND METHOD: Using 10 fresh wrists, with no pre-existing lesions, we studied the movements of the scaphoid, triquetrum and capitate produced by the isometrical loading of the muscles which move the wrist, each of them isolated or combined, before and after cutting off the scapholunate ligaments. To do this, we placed sensors in each of these bones and used the Fastrack system to record these movements. RESULTS: The simultaneous loading of the muscles of the wrist produce rotational movements in flexion and supination of the proximal carpal row. After cutting off the scapholunate ligaments, the scaphoid rotates in pronation and flexion, while the triquetrum rotates in pronation and extension. In this situation of a scapholunate lesion, the muscles that worsen the carpal dexasation are the extensor carpi ulnaris and flexor carpi ulnaris. On the other hand, the isolated loading of the radial muscles reduce the scapholunate diastasis, thus improving the carpal alignment. CONCLUSION: In dynamic scapholunate instabilities, isometric contraction of the ulnar carpal muscles must be avoided, as it promotes the scapholunate diastasis. The rest of the muscles have the opposite effect, stabilizing the carpus when primary stabilizers have failed.

[Carpal dynamic stability mechanisms. Experimental study]. / Mecanismos de estabilización dinámica del carpo. Estudio experimental.

OBJECTIVE: To evaluate, experimentally in cadavers, the effect of the motor muscles in the wrist in the kinetic behaviour of the carpal, under axial load, and the wrist in a neutral position. MATERIAL AND METHOD: The changes in the spatial orientation of the carpal bones were recorded with a movement trajectory gauge that functions with electromagnetic fields. A total of 30 fresh cadaver wrists were used, in which the principal motor tendons were isolated and subjected to loads proportional to the area of the physiological section of each muscle. The experiment was performed under isometric load conditions of all the tendons, and separately from each tendon. RESULTS: The simultaneous load of all the tendons studied caused a three-dimensional change of the carpal bones. The flexor carpi radialis led to supination of the scaphoids and pronation of the pyramidal. Conversely, the isolated load of the flexor carpi ulnaris, abductor pollicis longus and the extensor carpi radialis longus, caused a supination movement of the 2 carpal rows. Only the extensor carpi ulnaris led to a marked pronation of the carpal. COMMENTS AND CONCLUSIONS: The forearm muscles, as well as the movements of the wrist, cause pronation/supination/supination, flexion/extension and radial/cubital inclination movements. It is proposed that the most important movements in the dynamic stabilisation of the carpal are the intercarpal pronation and supination movements provoked by these muscles. Depending on the carpal injury mechanism or instability, the stimulating of one muscle group or the other may be beneficial.

Mecanismos de estabilización dinámica del carpo. Estudio experimental / Carpal dynamic stability mechanisms. Experimental study

Objetivo. Valorar de forma experimental en cadáver el efecto de los músculos motores de la muñeca en el comportamiento cinético del carpo, bajo carga axial y en posición neutra de la muñeca. Material y método. Se registraron los cambios de orientación espacial de los huesos del carpo, con un registrador de trayectoria de movimiento que funciona con campos electromagnéticos. Se utilizaron 30 muñecas de cadáver fresco, cuyos principales tendones motores de la muñeca fueron aislados y sujetos a cargas proporcionales al área seccional fisiológica de cada músculo. El experimento se llevó a cabo en condiciones de carga isométrica de todos los tendones, y de forma aislada de cada tendón. Resultados. La carga simultánea de todos los tendones estudiados provocó una modificación de la posición tridimensional de los huesos del carpo. El flexor carpi radialis provocó supinación del escafoides y pronación del piramidal. En cambio, la carga aislada del flexor carpi ulnaris, abductor pollicis longus y extensor carpi radialis longus provocaron un movimiento de supinación de las 2 filas del carpo. Solo el extensor carpi ulnaris provocó una pronación marcada del carpo. Comentarios y conclusiones. Los músculos del antebrazo, además de los movimientos de la muñeca, provocan movimientos de pronación/supinación, flexión/extensión e inclinación radial/cubital. Proponemos que el movimiento más importante en la estabilización dinámica del carpo son los movimientos de pronación y supinación intercarpiana provocados por estos músculos. Según el mecanismo lesional o inestabilidad carpiana, puede ser beneficiosa la potenciación de un grupo muscular u otro (AU)

Objective. To evaluate, experimentally in cadavers, the effect of the motor muscles in the wrist in the kinetic behaviour of the carpal, under axial load, and the wrist in a neutral position. Material and method. The changes in the spatial orientation of the carpal bones were recorded with a movement trajectory gauge that functions with electromagnetic fields. A total of 30 fresh cadaver wrists were used, in which the principal motor tendons were isolated and subjected to loads proportional to the area of the physiological section of each muscle. The experiment was performed under isometric load conditions of all the tendons, and separately from each tendon. Results. The simultaneous load of all the tendons studied caused a three-dimensional change of the carpal bones. The flexor carpi radialis led to supination of the scaphoids and pronation of the pyramidal. Conversely, the isolated load of the flexor carpi ulnaris, abductor pollicis longus and the extensor carpi radialis longus, caused a supination movement of the 2 carpal rows. Only the extensor carpi ulnaris led to a marked pronation of the carpal. Comments and conclusions. The forearm muscles, as well as the movements of the wrist, cause pronation/supination/supination, flexion/extension and radial/cubital inclination movements. It is proposed that the most important movements in the dynamic stabilisation of the carpal are the intercarpal pronation and supination movements provoked by these muscles. Depending on the carpal injury mechanism or instability, the stimulating of one muscle group or the other may be beneficial (AU)

Role of the extensor carpi ulnaris and its sheath on dynamic carpal stability.

Ten cadaveric forearms were tested using a wrist testing apparatus specifically designed to investigate the mechanisms of muscle stabilization of the wrist. The specimens were set in a jig allowing the distal row to migrate proximally and rotate around the axis of pronosupination. The extensor carpi ulnaris (ECU) was loaded with specific weights. Reactive rotations of the scaphoid, triquetrum, and capitate were measured by an electromagnetic motion tracking device. Loading the ECU caused pronation of both proximal and distal rows. After sectioning its sheath, the overall direction of the movement remained unchanged, but there was a 40% and 50% decrease of the pronation power over the distal and proximal carpal row, respectively. In addition to stabilizing the distal radiolunar joint, the ECU is an important structure that contributes to the dynamic stability of the wrist. Furthermore, its sheath plays a crucial role in maintaining the effect of the ECU muscle on the carpus.

Estudio experimental de las consecuencias de la sección del retináculo flexor sobre la estabilidad del escafoides / Experimental study of the consequences of resection of the flexor retinaculum on the stability of the scaphoids

Objetivo. Valorar de forma experimental las consecuencias de la sección del retináculo flexor (RF) en el comportamiento cinético del escafoides, piramidal y hueso grande, bajo carga axial. Material y método. Utilizando sensores de posición y orientación, tipo Fastrak™, se realizó un registro de los cambios de orientación espacial del escafoides y piramidal en relación al radio, al aplicar una carga axial. Para ello se utilizaron 6 muñecas de cadáver fresco, cuyos principales tendones motores fueron sujetos a cargas proporcionales al área seccional fisiológica de cada músculo. El experimento se llevó a cabo en condiciones de carga isométrica, con la muñeca en posición neutra, antes y después de seccionar el RF. Resultados. Tras la sección del RF, el escafoides manifestó una menor flexión (p=0,05) y una mayor inclinación radial (p=0,03) que cuando la misma carga se aplicó en la muñeca con RF íntegro. El comportamiento cinético del piramidal no cambió significativamente. Discusión. Según los resultados de este trabajo, la sección aislada del RF no genera una mayor inestabilidad del escafoides. Si fuese así, el escafoides debería presentar un mayor grado de flexión y en cambio ocurre todo lo contrario. Conclusión. La sección del RF modifica el comportamiento cinético del escafoides bajo carga axial, pero no genera mayor inestabilidad carpiana. El síndrome del pilar, no debería ser entendido como la consecuencia de la desestabilización del escafoides, sino de otro tipo de disfunción a determinar en futuros estudios (AU)

Objective. To analyze the consequences of flexor retinaculum (FR) section on the kinetic behavior of the scaphoid, triquetrum and capitate bones under axial load. Material and method. A 6 degree-of-freedom electromagnetic motion tracking device with sensors attached to the scaphoid, triquetrumcapitate and radius was used to monitor spatial changes in carpal bone alignment as a result of isometrically loading the main motor writs muscles. Six wrists from fresh cadavers were used, in which the principal motor tendons were subjected to loads proportional to physiological cross sectional area of each muscle. The experiment was carried out with the wrist in the neutral position, before and after the FR section. Results. After FR section, the scaphoid showed less flexion (P = .05) and a higher degree of radial inclination (P = .03) compared to the same experiment with the FR intact. The kinetic behavior of the triquetrum did not change significantly. Discussion. According to the results of this study, the isolated section of the FR did not produce greater instability of the scaphoid. If so, the scaphoid should have a higher degree of flexion, but exactly the opposite movement happens. Conclusion. Resection of the FR alters the kinetic behavior of the scaphoid under axial load, but does not produce greater instability in the carpus. Pillar syndrome may not be as a result of scaphoid instability, but due to another type of dysfunction that needs to be determined in future studies (AU)

Effects of forearm muscles on carpal stability.

Thirty cadaveric forearms were tested using a wrist testing apparatus specifically designed to investigate the mechanisms of muscle stabilization of the wrist. The specimens were set in a jig allowing the distal row to migrate proximally and to rotate around the pronosupination forearm axis. Five wrist motor tendons (FCR, FCU, ECU, ECRL and APL) were loaded with specific weights. Reactive rotations of the scaphoid, triquetrum and capitate were measured by an electromagnetic motion tracking device. When all five tendons were loaded simultaneously, the capitate supinated and the proximal row predominantly supinated and flexed. By contrast, when the ECU was loaded in isolation, it caused pronation to both proximal and distal rows. The FCR exhibited a mixed effect pronating the capitate and triquetrum, whilst supinating the scaphoid. Based on this, a hypothesis is proposed linking wrist stability to the balance of wrist pronators (ECU and FCR) and supinators (FCU, ECRL and APL).

The role of the flexor carpi radialis muscle in scapholunate instability.

PURPOSE: The flexor carpi radialis (FCR) muscle has been suggested to act as a dynamic scaphoid stabilizer. Because the FCR tendon uses the scaphoid tuberosity as a pulley to reach its distal insertion onto the second metacarpal, it has been hypothesized that FCR muscle contraction generates a dorsally directed vector that resists the scaphoid from rotating into flexion. The purpose of the present study was to validate that hypothesis and clarify the role of the FCR as a dynamic scaphoid stabilizer. METHODS: Ten fresh cadaver wrist specimens were tested. A custom-designed testing apparatus was used to hold the forearm and wrist vertically, in neutral forearm rotation. A 6-degree-of-freedom, electromagnetic motion-tracking device, with sensors attached to the scaphoid, triquetrum, capitate, and radius, was used to monitor spatial changes in carpal alignment as a result of isometrically loading the FCR in 5 different wrist positions. RESULTS: In all specimens and all wrist positions, the scaphoid consistently rotated into flexion when the FCR was loaded. It also exhibited variable degrees of pronation or supination, depending on whether the wrist was in flexion or extension. When the wrist was loaded in neutral position, the scaphoid consistently supinated and the triquetrum pronated, these differences being statistically significant (p < .05). CONCLUSIONS: The scaphoid consistently rotated into flexion and supination when the FCR was loaded, while the triquetrum rotated in flexion and pronation. The positive effects of FCR muscle re-education in dynamic scapholunate instabilities can be explained not by this muscle's capability of extending the scaphoid, as has often been hypothesized, but by its ability to induce supination to the scaphoid and pronation to the triquetrum. Such opposite rotations are likely to result in a dorsal coaptation of the scapholunate joint with relaxation of the dorsal scapholunate ligament.

Tratamiento quirúrgico de las pseudoartrosis asépticas de diáfisis humeral: ¿placa a compresión o clavo cerrojado? / Surgical treatment of non-septic humeral diaphyseal non-unions: compression plate or locking nail?

Objetivos. Comparar la placa a compresión con el clavo encerrojado, valorar el empleo del injerto óseo, valorar la utilidad de la cruentación y compresión del foco y determinar la existencia de factores pronóstico en el tratamiento quirúrgico de la pseudoartrosis aséptica de la diáfisis humeral. Material y método. Se ha realizado un estudio clínico multicéntrico incluyendo retrospectivamente 54 pseudoartrosis asépticas de la diáfisis humeral intervenidas entre 1994 y 2003. Se analizaron tres grupos de factores (de filiación, asociados al traumatismo inicial y asociados a la técnica quirúrgica) y se estudió su relación estadística con la consolidación, el tiempo de consolidación y las complicaciones posoperatorias. Resultados. La consolidación de la serie fue del 72,5% con un tiempo medio de consolidación de 21 semanas y un porcentaje de complicaciones del 20,4%. Han aumentado significativamente (p < 0,05) la consolidación: el tratamiento con clavo en las pseudoartrosis atróficas y con placa en las hipertróficas. Han acortado el tiempo de consolidación (p < 0,05) las fracturas inicialmente simples (tipo A) y las tratadas en principio de manera conservadora. Han disminuido las complicaciones posoperatorias (p < 0,05) aquellas fracturas inicialmente simples (tipo A). Conclusiones. No existen diferencias entre los dos implantes estudiados en cuanto a consolidación, tiempo de consolidación y complicaciones, sin embargo, las pseudoartrosis atróficas obtienen mejores resultados con clavo y las hipertróficas con placa. El aporte de injerto no ha demostrado mejorar los resultados. El enclavado debe de realizarse a foco abierto para cruentar y comprimir el foco. No se han encontrado factores pronóstico

Purpose. To compare the use of compression plates with locking nails, to assess the value of bone grafting, to assess the value of curettage and fracture site compression and to determine prognostic factors in the surgical treatment of non-septic humeral diaphyseal non-union. Materials and methods. A retrospective multicenter clinical study was performed of 54 non-septic humeral diaphyseal non-unions surgically treated from 1994 to 2003. Three groups of factors were analyzed (patient characteristics, initial trauma and surgical technique) and their statistic relationship with achievement of union, time to union and postoperative complications. Results. The series had a consolidation rate of 72.5% with a mean time to consolidation of 21 weeks and a complication rate of 20.4%. Factors that significantly increased union (p < 0.05) were: nailing in atrophied non-unions and plates in hypertrophied non-unions. Time to union was shorter (p < 0.05) in initially simple fractures (type A) and those initially treated conservatively. Postoperative complications decreased (p < 0.05) in initially simple fractures (type A). Conclusions. No differences were found between the two implants studied as to union, time to union and complications. However, better results were seen with nailing in atrophied non-unions and plates in hypertrophied non-unions. The use of grafts was not seen to improve results. Open nailing must be carried out so as to perform curettage and compression of the fracture focus. No prognostic factors were identified