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

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

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

Architectural changes in superficial and deep compartments of the tibialis anterior during electrical stimulation over different sites

Dette er siste tekst-versjon av artikkelen, og den kan inneholde små forskjeller fra forlagets pdf-versjon. Forlagets pdf-versjon finner du her: https://doi.org/doi.org/10.1109/TNSRE.2020.3027037 / This is the final text version of the article, and it may contain minor differences from the journal's pdf version. The original publication is available here: https://doi.org/doi.org/10.1109/TNSRE.2020.3027037Electrical stimulation is widely used in rehabilitation to prevent muscle weakness and to assist the functional recovery of neural deficits. Its application is however limited by the rapid development of muscle fatigue due to the non-physiological motor unit (MU) recruitment. This issue can be mitigated by interleaving muscle belly (mStim) and nerve stimulation (nStim) to distribute the temporal recruitment among different MU groups. To be effective, this approach requires the two stimulation modalities to activate minimally-overlapped groups of MUs. In this manuscript, we investigated spatial differences between mStim and nStim MU recruitment through the study of architectural changes of superficial and deep compartments of tibialis anterior (TA). We used ultrasound imaging to measure variations in muscle thickness, pennation angle, and fiber length during mStim, nStim, and voluntary (Vol) contractions at 15% and 25% of the maximal force. For both contraction levels, architectural changes induced by nStim in the deep and superficial compartments were similar to those observed during Vol. Instead, during mStim superficial fascicles underwent a greater change compared to those observed during nStim and Vol, both in absolute magnitude and in their relative differences between compartments. These observations suggest that nStim results in a distributed MU recruitment over the entire muscle volume, similarly to Vol, whereas mStim preferentially activates the superficial muscle layer. The diversity between spatial recruitment of nStim and mStim suggests the involvement of different MU populations, which justifies strategies based on interleaved nerve/muscle stimulation to reduce muscle fatigue during electrically-induced contractions of TA.acceptedVersionInstitutt for fysisk prestasjonsevne / Department of Physical Performanc

Comparative review of human and canine osteosarcoma: morphology, epidemiology, prognosis, treatment and genetics

Osteosarcoma (OSA) is a rare cancer in people. However OSA incidence rates in dogs are 27 times higher than in people. Prognosis in both species is poor, with five year osteosarcoma survival rates in people not having improved in decades. For dogs, one year survival rates are only around ~45%. Improved and novel treatment regimens are urgently required to improve survival in both humans and dogs with OSA. Utilising information from genetic studies could assist in this in both species, with the higher incidence rates in dogs contributing to the dog population being a good model of human disease. This review compares the clinical characteristics, gross morphology and histopathology, aetiology, epidemiology, and genetics of canine and human osteosarcoma. Finally, the current position of canine osteosarcoma genetic research is discussed and areas for additional work within the canine population are identified