Electromagnetic stimulation as coadjuvant in the healing of diaphyseal femoral fractures: a randomized controlled trial.

INTRODUCTION: There is controversy in medical literature regarding the use of electromagnetic fields to promote bone healing. METHODS: After designing and building devices capable of generating an electromagnetic field for this study, their safety was confirmed and the electromagnetic therapy was randomly allocated and compared to placebo in patients with fracture of the femoral diaphysis. Treatment began six weeks after the fracture and it was administered once a day, during 1 h, for eight consecutive weeks. Twenty device were built, 10 of which were placebo-devices. Between June 2008 and October 2009, 64 patients were randomized in two different hospitals and were followed for 24 weeks. The mean age was 30 years (18-59) and 81% were males. RESULTS: Healing observed at week 12 was 75% vs. 58% (p=0.1); at week 18 it was 94% vs. 80% (p=0.15); and at week 24 it was 94% vs. 87% (p=0.43) for the device group and the placebo group, respectively. DISCUSSION: This study suggests that an electromagnetic field stimulus can promote earlier bone healing compared to placebo in femoral diaphyseal fractures. Faster bone healing translates into sooner weight bearing, which--in turn--permits quicker return to normal daily activities.

INTRODUCCIÓN: El uso de estimulación electromagnética como coadyuvante en la consolidación de fracturas es controversial en la literatura médica. MÉTODOS: Para este estudio, se diseñó y construyó un dispositivo capaz de generar un campo electromagnético. Tras confirmar su seguridad se asignaron pacientes aleatoriamente con fractura diafisaria de fémur a recibir terapia electromagnética o placebo. La estimulación inició a las seis semanas de la fractura, 1 h diaria, por ocho semanas consecutivas. Se construyeron 20 dispositivos, 10 reales y 10 dispositivos-placebo. Entre junio 2008 y octubre 2009, ingresaron 64 pacientes al estudio de dos instituciones y fueron seguidos durante 24 semanas. El promedio de edad de los pacientes fue de 30 años (rango 18-59) y 81% eran de sexo masculino. RESULTADOS: La consolidación observada para el grupo con el dispositivo y el grupo placebo fue: en la semana 12, 75% vs. 58% (p= 0.1); en la semana 18, 94% vs. 80% (p= 0.15) y en la semana 24, 94% vs. 87% (p= 0.43). DISCUSIÓN: Este estudio muestra una tendencia a la consolidación más temprana al estar expuesto a un campo electromagnético frente a placebo. Una consolidación más temprana permite un apoyo precoz y, así, más rápida reincorporación al trabajo y a las actividades cotidianas.

Electromagnetic stimulation as coadjuvant in the healing of diaphyseal femoral fractures: a randomized controlled trial / Estimulación electromagnética como coadyuvante en el tratamiento de fracturas diafisarias de fémur: Ensayo clínico aleatorio

Introduction: There is controversy in medical literature regarding the use of electromagnetic fields to promote bone healing. Methods: After designing and building devices capable of generating an electromagnetic field for this study, their safety was confirmed and the electromagnetic therapy was randomly allocated and compared to placebo in patients with fracture of the femoral diaphysis. Treatment began six weeks after the fracture and it was administered once a day, during 1 h, for eight consecutive weeks. Twenty devices were built, 10 of which were placebo-devices. Between June 2008 and October 2009, 64 patients were randomized in two different hospitals and were followed for 24 weeks. The mean age was 30 years (18-59) and 81% were males. Results: Healing observed at week 12 was 75% vs. 58% (p= 0.1); at week 18, it was 94% vs. 80% (p= 0.15); and at week 24, it was 94% vs. 87% (p= 0.43) for the device group and the placebo group, respectively. Discussion: This study suggests that an electromagnetic field stimulus can promote earlier bone healing compared to placebo in femoral diaphyseal fractures. Faster bone healing translates into sooner weight bearing, which - in turn - permits quicker return to normal daily activities.

Introducción: El uso de estimulación electromagnética como coadyuvante en la consolidación de fracturas es controversial en la literatura médica. Métodos: Para este estudio, se diseñó y construyó un dispositivo capaz de generar un campo electromagnético. Tras confirmar su seguridad se asignaron pacientes aleatoriamente con fractura diafisaria de fémur a recibir terapia electromagnética o placebo. La estimulación inició a las seis semanas de la fractura, 1 h diaria, por ocho semanas consecutivas. Se construyeron 20 dispositivos, 10 reales y 10 dispositivos-placebo. Entre junio 2008 y octubre 2009, ingresaron 64 pacientes al estudio de dos instituciones y fueron seguidos durante 24 semanas. El promedio de edad de los pacientes fue de 30 años (rango 18-59) y 81% eran de sexo masculino. Resultados: La consolidación observada para el grupo con el dispositivo y el grupo placebo fue: en la semana 12, 75% vs. 58% (p =0.1); en la semana 18, 94% vs. 80% (p =0.15) y en la semana 24, 94% vs. 87% (p =0.43). Discusión: Este estudio muestra una tendencia a la consolidación más temprana al estar expuesto a un campo electromagnético frente a placebo. Una consolidación más temprana permite un apoyo precoz y, así, más rápida reincorporación al trabajo y a las actividades cotidianas.

Computational 3D model of in-vitro cell stimulated by electric and magnetic fields.

This work presents the development of 3D computational models that represent two studies about in-vitro cellular experimentation of cell stimulated by magnetic and electric field. The development considered the construction of the stimulation devices, the cell seeding, and the creation of the 3D computational models representing the arrangements. The models and their electromagnetic analysis were done in the ANSYS program. The volumes considered were: source of stimulation, Falcon cell culture plate, cell content, and space for zero potential. The electric field stimulation model considered an applied electric field between 250 V/m and 1 kV/m. While the magnetic field stimulation model considered an applied magnetic field between 0.5 mT and 2.0 mT. For both models, the frequency range was between 5 Hz and 105 Hz. As a result, the error between the stimulation devices and the created models was lower than 5%. The homogeneous area of the magnetic and electric field was established and the behavior of field strength produced by the stimulation devices was the expected one. In both models, the induced current density was the variable evaluated in the cellular material. The current density induced by the applied magnetic field was greater than by the applied electric field.

Magnetic stimulation for fracture consolidation--clinical study.

This paper presents a randomized clinical design for evaluating magnetic fields in the consolidation of femoral shaft fractures. The study involved the design and construction of 20 devices (stimulators and placebos) and the development of 3D computer models of stimulated patient's thighs. A total of 64 patients were included in the study. Follow up time was 8 weeks with 1 hour of stimulation a day. The electrical signals estimated in the computer models were magnetic field, current density and voltage for different frequencies and currents. The results revealed 83% consolidated cases, and 7% with nonunion within the stimulation group, and 72% of consolidated cases and 14% with non-union for the control group. The consolidation results of patients who received stimulation were superior in time and number, but were not statistically significant. The values of electrical variables estimated by the computational model were found to be within a range not harmful to the patient (µA/m2, µT, nV).

Computation electrical variables induced by magnetic stimulation in 3D thigh model.

This paper presents the changes in the electrical variables induced in a 3D thigh model with femoral diaphyseal fracture when it is magnetically stimulated. Three cases with particular geometries of the models were considered: skin, muscle, cortical bone (CB), bone marrow, metal pin, and fracture shape. Fracture shape included electric properties for blood, cartilage, trabecular bone (TB), and cortical bone (CB), to represent the consolidation process. A Helmholtz coil was added to the thigh model as stimulation source. The stimulation signal was between 0.5 and 2 mT, and between 5 and 100 Hz. The results shown than induced electric signals were higher for a change in frequency than a change in magnetic field. An important dependence between frequency, magnetic field, fracture shape, and fracture properties was found. The result suggest that the consolidation process could be better if different magnetic stimulation levels were considered.