RESUMO
Positive effects of Capacitive Coupling Electric Field (CCEF) stimulation are described for several orthopedic indications such as the healing of recent fractures, non-unions and spinal fusion, due to the capacity to involve the up-regulation of osteopromotive factors. In vitro studies on MC3T3-E1 bone cells showed that CCEF acts opening the plasma membrane voltage gated calcium channels, thus increasing the cytosolic calcium concentration and the phospholipase A2 (PLA2) activity. Cytosolic calcium activates the calmodulin pathway, thus resulting in an up-regulated expression of osteogenic genes, such as transforming growth factor-ß superfamily genes (TGF-ß1, -ß2 -ß3, bone morphogenetic protein-2 and -4), fibroblast growth factor (FGF)-2, osteocalcin (BGP) and alkaline phosphatase (ALP). PLA2 acts increasing the synthesis of Prostaglandin E2 (PGE2), which promotes osteogenesis by raising the cellular L-ascorbic acid uptake through the membrane carrier sodium vitamin C transporter-2 (SVCT-2). In vivo, Brighton et al. in a castration-induced osteoporosis animal model, demonstrated that CCEF was able to restore bone mass/unit volume in the rat vertebral body. To investigate the role of CCEF stimulation in vertebral bone marrow edema (VBME) its percentage was assessed in 24 patients with 25 acute vertebral compression fractures (VCFs) conservatively treated with CCEF (group A) or without CCEF (group B) using serial MR imaging follow-up at 0, 30, 60, 90 days. Pain and quality of life were assessed by visual analog scale (VAS) and Oswestry Low Back Disability Index (ODI) in the same periods. At 90 day follow-up the complete resolution of VBME was found only in group A (p=0.0001). A significant improvement of VAS (p=0.007) and ODI (p=0.002) was also observed in group A. This preliminary observational study shows that patients treated with CCEF stimulation present an improvement of clinical symptoms with faster fracture healing and a complete VBME resolution.
Assuntos
Dor nas Costas/terapia , Terapia por Estimulação Elétrica/métodos , Consolidação da Fratura , Compressão da Medula Espinal/terapia , Fraturas da Coluna Vertebral/terapia , Animais , Dor nas Costas/patologia , Dor nas Costas/fisiopatologia , Edema/patologia , Edema/fisiopatologia , Edema/terapia , Feminino , Seguimentos , Humanos , Masculino , Estudos Prospectivos , Ratos , Compressão da Medula Espinal/patologia , Compressão da Medula Espinal/fisiopatologia , Fraturas da Coluna Vertebral/patologia , Fraturas da Coluna Vertebral/fisiopatologiaRESUMO
Osteoarthritis (OA) is a joint pathology characterized by fibrillation, reduced cartilage thickness and subchondral bone sclerosis. There is evidence that pulsed electromagnetic fields (PEMFs) counteract OA progression, but the effect of two different PEMF frequencies has not yet been shown. The aim of this study was to test the effectiveness of PEMFs at two different frequencies (37 and 75 Hz) in a late OA stage in 21-month-old Guinea pigs. After 3 months of 6 h/day PEMF stimulation, histological and histomorphometric analyses of the knees were performed. At both frequencies, PEMFs significantly reduced histological cartilage score, fibrillation index (FI), subchondral bone thickness (SBT) and trabecular number (Tb.N) and increased trabecular thickness (Tb.Th) and separation (Tb.Sp) in comparison to the not treated SHAM group. However, PEMFs at 75 Hz produced significantly more beneficial effects on the histological score and FI than 37 Hz PEMFs. At 75 Hz, PEMFs counteracted cartilage thinning as demonstrated by a significantly higher cartilage thickness values than either those of the SHAM or 37 Hz PEMF-treated groups. Although in severe OA both PEMF frequencies were able to limit its progression, 75 Hz PEMF stimulation achieved the better results.
Assuntos
Magnetoterapia/métodos , Osteoartrite/terapia , Animais , Cartilagem Articular/patologia , Cobaias , Masculino , Osteoartrite/patologiaRESUMO
The execution technique of hanging, introduced by the Angle, Saxon, and Jute Germanic tribes during their invasions of the Roman Empire and Britain in the 5th century, has remained largely unchanged over time. The earliest form of a gallows was a tree on which prisoners were hanged. Despite the introduction of several modifications such as a trap door, the main mechanism of death remained asphyxiation. This created the opportunity for attempted revival after the execution, and indeed several well-known cases of survival following judicial hanging have been reported. It was not until the introduction of the standard drop by Dr. Samuel Haughton in 1866, and the so-called long drop by William Marwood in 1872 that hanging became a standard, humane means to achieve instantaneous death. Hangmen, however, fearing knot slippage, started substituting the subaural knot for the traditional submental knot. Subaural knots were not as effective, and cases of decapitation were recorded. Standardization of the long drop was further propagated by John Berry, an executioner who used mathematical calculations to estimate the correct drop length for each individual to be hanged. A British committee on capital sentences, led by Lord Aberdare, studied the execution method, and advocated for the submental knot. However, it was not until Frederic Wood-Jones published his seminal work in 1913 that cervical fractures were identified as the main mechanism of death following hanging in which the long drop and a submental knot were used. Schneider introduced the term "hangman's fracture" in 1965, and reported on the biomechanics and other similarities of the cervical fractures seen following judicial hangings and those caused by motor vehicle accidents.
Assuntos
Asfixia/história , Pena de Morte/história , Vértebras Cervicais/lesões , Medicina nas Artes , Pinturas/história , Fraturas da Coluna Vertebral/história , Fenômenos Biomecânicos , Europa (Continente) , História do Século XV , História do Século XVI , História do Século XVII , História do Século XVIII , História do Século XIX , História do Século XX , História Antiga , História Medieval , Humanos , Estados UnidosRESUMO
An experimental in vivo study was performed to test if the effect of Pulsed Electromagnetic Fields (PEMFs) on chondrocyte metabolism and adenosine A2a agonist activity could have a chondroprotective effect on the knee of Dunkin Hartley guinea-pigs of 12 months with spontaneously developed osteoarthritis (OA). After a pilot study, 10 animals were randomly divided into two groups: PEMF-treated group (6 h/day for 3 months) and Sham-treated group. Microradiography and histomorphometry were performed on the entire articular surface of knee joints used in evaluating chondropathy severity, cartilage thickness (CT), cartilage surface Fibrillation Index (FI), subchondral bone plate thickness (SBT) and histomorphometric characteristics of trabecular epiphyseal bone. The PEMF-treated animals showed a significant reduction of chondropathy progression in all knee examined areas (p<0.05). CT was significantly higher (p<0.001) in the medial tibia plateaus of the PEMF-treated group when compared to the Sham-treated group. The highest value of FI was observed in the medial tibia plateau of the Sham-treated group (p<0.05). Significant lower values were observed in SBT of PEMF-treated group in comparison to Sham-treated group in all knee examined areas (p<0.05). The present study results show that PEMFs preserve the morphology of articular cartilage and slower the progression of OA lesions in the knee of aged osteoarthritic guinea pigs. The chondroprotective effect of PEMFs was demonstrated not only in the medial tibial plateau but also on the entire articular surface of the knee.