Tratamiento de las complicaciones vasculares tras aplicación del método de Ilizarov: Aportación de tres casos

Entre 1987 y 1991 fueron intervenidos 209 pacientes mediante el método de Ilizarov en nuestra institución. Tres de los pacientes presentaron complicaciones vasculares durante el tratamiento. Todos ellos eran adultos y habían sido tratados por pseudoartrosis de un hueso largo. La lesión vascular ocurrió en la arteria femoral superficial en un caso, la arteria poplítea en otro y la arteria tibial posterior en el último de ellos. El signo clínico del problema vascular fue la presencia de la hemorragia en el punto de salida cutánea de las agujas de Kirschner de transfixión. Se realizó exploración arteriográfica en todos los casos, pero su interpretación fue difícil debido a la presencia del fijador externo. El tratamiento de la complicación vascular fue: en el caso de la lesión de la arteria femoral fue retirado el fijador y realizado un by-pass con un injerto invertido obtenido de la vena safena; en el caso de lesión de la arteria poplítea, se realizó la misma técnica pero sin retirar el fijador. En el último caso la lesión de la arteria tibial posterior se trató mediante ligadura de la misma. En todos los casos, la evolución del tratamiento vascular fue excelente, siendo posible finalizar el tratamiento ortopédico.From 1987 to 1991, 209 patients were operated on by the Ilizarov method in our institution. Among them, 3 patients presented vascular complications during the treatment. All were adults and have been treated for long bone pseudoarthrosis. The vascular lesion ocurred at the femoral superficial artery in one case, at the popliteal artery in other case, and at the posterior tibial artery in the third case. The clinical sign of vascular damage was bleeding through the cutaneous point of the Kirschnner transfixion wires in all cases. Arteriography was done in all cases but its interpretation was very difficult because of the presence of the external fixator. In the case of femoral artery, injury the external fixator was removed and a vascular by-pass was performed with an inverted graft of the saphenous vein. The same procedure was done in the case with a popliteal artery injury but without removal of the external fixator. The case with lesion of the posterior tibial artery was treated by arterial hgature. In all cases, outcome was satisfactory, allowing completion of the orthopaedic treatment

Characterization of the stimulation output of four devices for focal muscle vibration

Different devices for mechano-acoustic muscle vibration became available on the market in the last ten years. Although the use of these vibrators is increasing in research and clinical settings, the features of their stimulation output were never described in literature. In this study we aimed to quantify and compare the stimulation output of the four most widespread pneumatic devices for focal muscle vibration available on the market. A piezoelectric pressure sensor was used to measure the pressure profile generated by the four selected devices in the following experimental conditions: i) measurement of the output changes associated with variations of the stimulation amplitude for three stimulation frequencies (100 Hz, 200 Hz, and 300 Hz); ii) measurement of the output changes during a 20-min long stimulation at constant frequency (300 Hz) and amplitude; iii) measurement of the output changes associated with the progressive activation of all stimulation channels at constant frequency (200 Hz) for different amplitudes. The maximum peak-to-peak amplitudes of the pressure waves were in the range 102 mbar - 369 mbar (below the maximum values declared by the different manufacturers). The shape of the pressure waves generated by the four devices was quasi-sinusoidal and asymmetric with respect to the atmospheric pressure. All output features had a remarkable intra- and inter-device variability. Further studies are required to support the technological improvement of the currently available devices and to focus the issues of vibration effectiveness, limitations, proper protocols, modalities of its application and assessment in neuromuscular training and rehabilitation

Intermittent applied mechanical loading induces subchondral bone thickening that may be intensified locally by contiguous articular cartilage lesions

Objectives: Changes in subchondral bone (SCB) and cross-talk with articular cartilage (AC) have been linked to osteoarthritis (OA). Using micro-computed tomography (micro-CT) this study: (1) examines changes in SCB architecture in a non-invasive loading mouse model in which focal AC lesions are induced selectively in the lateral femur, and (2) determines any modifications in the contralateral knee, linked to changes in gait, which might complicate use of this limb as an internal control. Methods: Right knee joints of CBA mice were loaded: once with 2weeks of habitual use (n=7), for 2weeks (n=8) or for 5weeks (n=5). Both left (contralateral) and right (loaded) knees were micro-CT scanned and the SCB and trabecular bone analysed. Gait analysis was also performed. Results: These analyses showed a significant increase in SCB thickness in the lateral compartments in joints loaded for 5weeks, which was most marked in the lateral femur; the contralateral non-loaded knee also showed transient SCB thickening (loaded once and repetitively). Epiphyseal trabecular bone BV/TV and trabecular thickness were also increased in the lateral compartments after 5 weeks of loading, and in all joint compartments in the contralateral knee. Gait analysis showed that applied loading only affected gait in the contralateral himd-limb in all groups of mice from the second week after the first loading episode. Conclusions: These data indicate a spatial link between SCB thickening and AC lesions following mechanical trauma, and the clear limitations associated with the use of contralateral joints as controls in such OA models, and perhaps in OA diagnosis

Impact of borderline personality disorder traits on the association between age and health-related quality of life:A cohort study in the general population

Background Increasing age as well as borderline personality pathology are associated with a lower level of health-related quality of life (HR-QoL). Our objective was to investigate whether the presence of borderline personality traits modifies the association between age and HR-QoL in the general population. Methods Cross-sectional data from 5,303 respondents (aged 21-72 years) of the Netherlands Mental Health Survey and Incidence Study-2 were analyzed. Borderline personality traits were assessed with the International Personality Disorder Examination questionnaire. Mental and physical HR-QoL were measured with the Medical Outcomes Study Short Form Health Survey. Multiple linear regression analysis was used to examine the association of borderline personality traits, age and their interaction on mental as well as physical HR-QoL, adjusted for demographic variables as well as somatic and mental disorders. Results A total of 1,520 (28.7%) respondents reported one or more borderline personality traits of which 58 (1.1%) reported five or more indicative of a borderline personality disorder. A higher age was associated with lower physical HR-QoL. This negative association became significantly stronger in the presence of borderline personality traits. The association between increasing age and mental HR-QoL was positive in the absence of borderline personality traits and negative in the presence of borderline personality traits. Conclusion Borderline personality traits negatively interfere with the association between age and HR-QoL irrespective of somatic and mental disorders. Attention of clinicians and researchers for subthreshold borderline personality pathology is needed in middle-aged and older persons

How typhoons trigger turbidity currents in submarine canyons

Intense turbidity currents occur in the Malaylay Submarine Canyon off the northern coast of Mindoro Island in the Philippines. They start in very shallow waters at the shelf break and reach deeper waters where a gas pipeline is located. The pipeline was displaced by a turbidity current in 2006 and its rock berm damaged by another 10 years later. Here we propose that they are triggered near the mouth of the Malaylay and Baco rivers by direct sediment resuspension in the shallow shelf and transport to the canyon heads by typhoon-induced waves and currents. We show these rivers are unlikely to generate hyperpycnal flows and trigger turbidity currents by themselves. Characteristic signatures of turbidity currents, in the form of bed shear stress obtained by numerical simulations, match observed erosion/deposition and rock berm damage patterns recorded by repeat bathymetric surveys before and after typhoon Nock-ten in December 2016. Our analysis predicts a larger turbidity current triggered by typhoon Durian in 2006; and reveals the reason for the lack of any significant turbidity current associated with typhoon Melor in December 2015. Key factors to assess turbidity current initiation are typhoon proximity, strength, and synchronicity of typhoon induced waves and currents. Using data from a 66-year hindcast we estimate a ~8-year return period of typhoons with capacity to trigger large turbidity currents

Muscle fiber conduction velocity is more affected after eccentric than concentric exercise

It has been shown that mean muscle fiber conduction velocity (CV) can be acutely impaired after eccentric exercise. However, it is not known whether this applies to other exercise modes. Therefore, the purpose of this experiment was to compare the effects of eccentric and concentric exercises on CV, and amplitude and frequency content of surface electromyography (sEMG) signals up to 24 h post-exercise. Multichannel sEMG signals were recorded from biceps brachii muscle of the exercised arm during isometric maximal voluntary contraction (MVC) and electrically evoked contractions induced by motor-point stimulation before, immediately after and 2 h after maximal eccentric (ECC group, N = 12) and concentric (CON group, N = 12) elbow flexor exercises. Isometric MVC decreased in CON by 21.7 ± 12.0% (± SD, p < 0.01) and by 30.0 ± 17.7% (p < 0.001) in ECC immediately post-exercise when compared to baseline. At 2 h post-exercise, ECC showed a reduction in isometric MVC by 24.7 ± 13.7% (p < 0.01) when compared to baseline, while no significant reduction (by 8.0 ± 17.0%, ns) was observed in CON. Similarly, reduction in CV was observed only in ECC both during the isometric MVC (from baseline of 4.16 ± 0.3 to 3.43 ± 0.4 m/s, p < 0.001) and the electrically evoked contractions (from baseline of 4.33 ± 0.4 to 3.82 ± 0.3 m/s, p < 0.001). In conclusion, eccentric exercise can induce a greater and more prolonged reduction in muscle force production capability and CV than concentric exercis