PEMF Curatron Pulsed Electro-Magnetic Field Therapy by Curatronic

Fundamental and practical aspects of therapeutic uses of pulsed electromagnetic fields (PEMFs). 

The beneficial therapeutic effects of selected low-energy, time-varying magnetic fields, called PEMFs, have been documented with increasing frequency since 1973. Initially, this form of athermal energy was used mainly as a salvage for patients with long-standing juvenile and adult nonunions. Many of these individuals were candidates for amputation. Their clearly documented resistance to the usual forms of surgical treatment, including bone grafting, served as a reasonable control in judging the efficacy of this new therapeutic method, particularly when PEMFs were the sole change in patient management. More recently, the biological effectiveness of this approach in augmenting bone healing has been confirmed by several highly significant double-blind and controlled prospective studies in less challenging clinical circumstances. Furthermore, double-blind evidence of therapeutic effects in other clinical disorders has emerged. These data, coupled with well-controlled laboratory findings on pertinent mechanisms of action, have begun to place PEMFs on a therapeutic par with surgically invasive methods but at considerably less risk and cost. As a result of these clinical observations and concerns about electromagnetic "pollution", interactions of nonionizing electromagnetic fields with biological processes have been the subject of increasing investigational activity. Over the past decade, the number of publications on these topics has risen exponentially. They now include textbooks, speciality journals, regular reviews by government agencies, in addition to individual articles, appearing in the wide spectrum of peer-reviewed, scientific sources. In a recent editorial in Current Contents, the editor reviews the frontiers of biomedical engineering focusing on Science Citation Index methods for identifying core research endeavors. Dr. Garfield chose PEMFs from among other biomedical engineering efforts as an example of a rapidly emerging discipline. Three new societies in the bioelectromagnetics, bioelectrochemistry, and bioelectrical growth and repair have been organized during this time, along with a number of national and international committees and conferences. These activities augment a continuing interest by the IEEE in the U.S. and the IEE in the U.K. This review focuses on the principles and practice behind the therapeutic use of "PEMFs". This term is restricted to time-varying magnetic field characteristics that induce voltage waveform patterns in bone similar to those resulting from mechanical deformation. These asymmetric, broad-band pulses affect a number of biologic processes athermally. Many of these processes appear to have the ability to modify selected pathologic states in the musculoskeletal and other systems.
Bassett C. Dep. Orthopedic Surgery, Columbia University, New York. Crit Rev Biomed Eng 


Pulsed electromagnetic fields promote collagen production in bone marrow fibroblasts via athermal mechanisms. 

Primary and passaged cultures of fibroblasts (RBMFs) raised from the bone marrow stroma of young rabbits were treated with pulsed electromagnetic fields (PEMFs) from the start of each culture until 1 week after they became confluent. The PEMF treatment had no effect on cell proliferation, estimated by phase contrast microscopy, by 3H-thymidine incorporation into DNA, or by total DNA assay. Collagen production, estimated by conversion of 3H-proline to 3H-hydroxyproline in nondialyzable material was markedly elevated in postconfluent cultures, but not in cultures that had only just reached confluence. About 65 of 3H-hydroxyproline was in low molecular weight form, and a correlation between collagen breakdown and cyclic AMP (cAMP) levels in RBMFs was demonstrated by adding dibutyryl cAMP or prostaglandin E3 (PGE2) to the culture medium concurrently with 3H-proline. The PEMF apparatus caused an insufficient temperature rise (less than 0.1 degree C) to account for these results. We propose that the rise in collagen production is consistent with the hypothesis that PEMFs act by reducing cAMP levels in RBMFs, and that thermal effects are insignificant.
Farndale R. et.al Calcif Tissue Int 


Modulation of collagen production in cultured fibroblasts by a low-frequency pulsed magnetic field. 

Primary cultures of chicken tendon fibroblasts have been exposed for various periods to a low-frequency, pulsed magnetic field, and the effects on protein and collagen synthesis have been examined by radioisotopic incorporation. Total protein synthesis was increased in confluent cells treated with a pulsed magnetic field for the last 24 h of culture as well as in cells treated for a total of 6 days. However, in 6 day-treated cultures, collagen accumulation was specifically enhanced as compared to total protein, whereas after short-term exposure, collagen production was increased only to the same extent as total protein. Levels of cyclic AMP were significantly decreased after 6-day pulsed magnetic field treatment, probably as a consequence of diminished adenylate cyclase activity. Exposure to pulsed magnetic field had no effect on cell proliferation or collagen phenotype. These results indicate that a pulsed magnetic field can specifically increase production of collagen, the major differentiated function of fibroblasts, possibly by altering cyclic-AMP metabolism.
Murray J. et.al. Biochim Biophys Acta 


Results of pulsed electromagnetic fields (PEMFs) in ununited fractures after external skeletal fixation. 

Of 147 patients with fractures of the tibia, femur and humerus, in whom an average of 3.3 operations had failed to produce union, all were treated with external skeletal fixation in situ and pulsed electromagnetic fields (PEMFs). Of the 147, 107 patients united for an overall success rate of 73%. Union of the femur occurred in 81% and the tibia in 75%. Only five of 13 humeri united. Failure to achieve union with PEMFs was most closely associated with very wide fracture gaps and insecure skeletal fixation devices.
Marcer M. et.al. Clin Orthop 


Osteonecrosis of the femoral head treated by pulsed electromagnetic fields (PEMFs): a preliminary report. 

This has been a preliminary report with a short-term follow-up of a small number of observations (28 hips of 24 patients). The follow-ups ranged from 6 to 36 months, with an average of 17.8 months. Only eleven hips (in eleven patients) were followed an average of 8 months after cessation of the treatment. It should be emphasized that this was a "pilot" study, in which no control series was used to determine the natural course of the disease in a comparable clinical setting. Of note was the pain relief, in 19 of 23 patients with moderate to severe pretreatment pain. Also there was an improved function, which suggests that at least in approximately two thirds of the patients there was some clinical benefit from this mode of treatment. In eight hips, clinical conditions did not change; and in two they worsened, requiring further treatment. Eighteen remaining hips were thought to have benefited by the treatment. Six femoral heads that had already developed varying degrees of collapse (Ficat Type III) collapsed further (1 to 2 mm), and two round heads (Ficat II) progressed to off-round (Ficat III). This preliminary study suggests that further exploration of pulsed electromagnetic fields (PEMFs) is warranted in the treatment of osteonecrosis of the femoral head.
Eftekhar N. et.al. Hip 


Treatment of therapeutically resistant non-unions with bone grafts and pulsing electromagnetic fields. 

This study reviews the cases of eighty-three adults with ununited fractures who were treated concomitantly with bone-grafting and pulsed electromagnetic fields. An average of 1.5 years had elapsed since fracture and the use of this combined approach. Nearly one-third of the patients had a history of infection, and an average of 2.4 prior operations had failed to produce bone union. Thirty-eight patients who were initially treated with grafts and pulsed electromagnetic fields for ununited fractures with wide gaps, synovial pseudarthrosis, and malalignment achieved a rate of successful healing of 87 per cent. Forty-five patients who had initially been treated unsuccessfully with pulsing electromagnetic fields alone had bone-grafting and were re-treated with pulsing electromagnetic fields. Ninety-three per cent of these fractures healed. The residual failure rate after two therapeutic attempts, one of which was operative, was 1.5 per cent. The median time to union for both groups of patients was four months.
Bassett C. Et.al. J Bone Joint Surg Am 


Effects of a pulsed electromagnetic field on a mixed chondroblastic tissue culture. 

A mixed tissue culture predominantly composed of chondroblastic tissue was perturbed by a pulsed electromagnetic field (PEMF). Some cultures were nonconfluent, and purposely retarded in growth to resemble an atrophic nonunion, while others were grown to confluence in about one-half the time as a model for a hypertrophic nonunion. These two groups tested the effect of growth rate upon the products of cell proliferation and differentiation. The slowly growing cultures were stimulated to synthesize hydroxyproline. The rapidly growing cultures showed a large increase in lysozyme activity, and increase in hyaluronate and DNA, and a decrease in glycosaminoglycan. Exogenous lysozyme further decreased the glycosaminoglycan synthesis in the presence of PEMF. Chitotriose, a specific lysozyme inhibitor abolished this effect. Cycloheximide, a protein synthesis inhibitor, did not abolish the activation of lysozyme found in the matrix. Thus lysozyme appears to be activated by PEMF. These observations of the rapidly growing confluent cultures are consistent with events described in the normal healing of a bone fracture or endochrondral growth. Thus, PEMF appears to promote normal healing, probably by altering cartilaginous lysozyme activity in the matrix, and possibly the sequence of events leading to calcification.
Norton LA Clin Orthop 


Biological effects of magnetic fields: studies with microorganisms. 

Five bacteria and one yeast were grown in magnetic fields of 50-900 gauss with frequencies of 0-0.3 HZ and square, triangular, or sine waveform. Growth of these microorganisms could be stimulated or inhibited depending upon the field strength and frequency of the pulsed magnetic field. Spore germination and mutation frequency were unaffected by the magnetic fields used in this study.
Moore R. Can J Microbiol 


Influence of magnetic fields on calcium salts crystal formation: an explanation of the 'pulsed electromagnetic field' technique for bone healing. 

In the search for a mechanism by means of which a magnetic field deparalyses non-unions and enhances bone tissue formation, the influence of continuous magnetic fields on the formation of calcium phosphate crystal seeds has been investigated. From this perspective, an explanation is given of a working mode in conventional equipment for pulsed electromagnetic field treatment; this is compared with multifunction equipment.
Madronero A J Biomed Eng

 

 

Treatment of nonunion using pulsed electromagnetic fields: a retrospective follow-up study. 

Pulsed electromagnetic fields (PEMF) are a useful means of treating cases of fracture nonunion. In 67.7% of nonunions with a disability time of at least 24 months, complete consolidation was obtained. This success rate is increased to 76.6% if we exclude nonunion, that presented contraindications for treatment with PEMF. The disability time had no effect on the success rate. Lesions of the humerus and atrophic nonunion had an unfavorable prognosis.
Meskens M. et.al. Dep. Orthopedic Surgery, University Hospital, Pellenberg, Belgium. Acta Orthop Belg 


Effects of pulsed electromagnetic fields on Steinberg ratings of femoral head osteonecrosis. 

95 Patients with femoral head osteonecrosis met the protocol for treatment of 118 hips with selected pulsed electromagnetic fields (PEMFs). Etiologies included trauma (17), alcohol (9), steroid use (46), sickle cell disease (2), and idiopathy (44). The average age was 38 years, and the average follow-up period since the onset of symptoms was 5.3 years. PEMF treatment had been instituted an average of 4.1 years earlier. By the Steinberg quantitative staging method of roentgenographic analysis, none of the 15 hips in Stages 0-III showed progression, and grading improved in nine of 15. Eighteen of 79 hips (23%) with Stage IV lesions progressed and none improved. In the Stage V category, one of 21 hips (5%) worsened and none improved. Three Stage VI lesions were unchanged. The overall rate of quantified progression for the 118 hips, 87% of which had collapse present when entering the program, was 16%. This value represents a reversal of the percentage of progression reported recently by other investigators using conservative and selected surgical methods. PEMF patients also have experienced long-term improvements in symptoms and signs, together with a reduction in the need for early joint arthroplasty. 
Bassett C. et.al. Orthopaedic Hospital, Riverdale, NY Clin Orthop 


Stimulation of experimental endochondral ossification by low-energy pulsing electromagnetic fields. 

Pulsed electromagnetic fields (PEMFs) of certain configuration have been shown to be effective clinically in promoting the healing of fracture nonunions and are believed to enhance calcification of extracellular matrix. In vitro studies have suggested that PEMFs may also have the effect of modifying the extracellular matrix by promoting the synthesis of matrix molecules. This study examines the effect of one PEMF upon the extracellular matrix and calcification of endochondral ossification in vivo. The synthesis of cartilage molecules is enhanced by PEMF, and subsequent endochondral calcification is stimulated. Histomorphometric studies indicate that the maturation of bone trabeculae is also promoted by PEMF stimulation. These results indicate that a specific PEMF can change the composition of cartilage extracellular matrix in vivo and raises the possibility that the effects on other processes of endochondral ossification (e.g., fracture healing and growth plates) may occur through a similar mechanism.
Aaron R. et.al. Dep. Biochemistry and Biophysics, University of Rhode Island J Bone Miner Res 


Role of pulsed electromagnetic fields in recalcitrant non-unions.

Twenty-nine patients of recalcitrant nonunion of long bones were treated by pulsed electromagnetic fields in an attempt to bring about osteogenesis. The pulse used was rectangular, equal mark space wave in the astable, continuous mode operating at a frequency of 40 Hertz. The success rate was 82.5%. The result was not dependent on the age, sex, time of nonunion or the presence of infection. However, the results were uniformly poor when infection and fracture instability were coexistent in the same patient.
Delima DF, Tanna DD J Postgrad Med 


In vitro low frequency electromagnetic field effect on fast axonal transport. 

The objective of this study was to evaluate the effects of a low frequency electromagnetic field on fast axonal transport for future neuroprosthetic applications. Changes in speeds and densities of retrograde fast organelle transport in rat sciatic nerve preparations were measured in vitro upon exposure to 15 and 50 Hz pulsed magnetic fields with peak intensities of 4.4 and 8.8 mT. Maximum current density of the induced eddy current was calculated to be about 40 microA/cm2. Video enhanced differential interference contrast microscopy was used to record axons supporting active organelle transport. Strong effects were observed in myelinated axons (cessation of transport in up to 10 min). Such effects may eventually be used as part of a neuroprosthesis to noninvasively modify or couple to various parts of the nervous system.
Zborowski M. et.al. Dep. Artificial Organs, Cleveland Clinic Found. ASAIO Trans 


Effects of pulsed extremely-low-frequency magnetic fields on skin wounds in the rat. 

Rats with skin-wounds surgically created on their backs were exposed immediately after surgery and every 12 h thereafter to pulsed, extremely-low-frequency magnetic fields. The shape of the pulse was a positive triangle (50 Hz, 8 mT peak). The rate of healing of skin wounds was evaluated macroscopically and by light and electron microscopy at 6, 12, 21, and 42 days after the operation. A significant increase in the rate of wound contraction was found in rats treated with magnetic fields. Forty-two days after surgery all treated animals show fully closed wounds, while control rats at the same time intervals still lacked a final 6% of the wound surface to be covered. Treated rats showed earlier cellular organization, collagen formation and maturation, and a very early appearance of newly formed vascular network.
Ottani V. et.al. Istituto di Anatomia, Bologna, Italy. Bioelectromagnetics 


Treatment of delayed union and nonunion of the tibia by pulsed electromagnetic
fields. A retrospective follow-up. 

The results of a clinical follow-up of 57 tibial lesions treated with pulsed electromagnetic fields at least six months after the primary lesion occurred proved that this noninvasive method can be a valuable alternative to other commonly accepted modes of therapy. The overall success rate was 75% but could be improved to 81% when the proper indications were met.
Meskens M. et.al. Dep. Orthopaedics, University Hospital, Pellenberg Bull Hosp Jt Dis Orthop Inst 


Enhanced responsiveness to parathyroid hormone and induction of functional differentiation of cultured rabbit costal chondrocytes by a pulsed electromagnetic field. 

Pulsed electromagnetic fields promote healing of delayed united and ununited fractures by triggering a series of events in fibrocartilage. We examined the effects of a pulsed electromagnetic field (recurrent bursts, 15.4 Hz, of shorter pulses of an average of 2 gauss) on rabbit costal chondrocytes in culture. A pulsed electromagnetic field slightly reduced the intracellular cyclic adenosine 3',5'-monophosphate (cAMP) level in the culture. However, it significantly enhanced cAMP accumulation in response to parathyroid hormone (PTH) to 140% of that induced by PTH in its absence, while it did not affect cAMP accumulation in response to prostaglandin E1 or prostaglandin I2. The effect on camp accumulation in response to PTH became evident after exposure of the cultures to the pulsed electromagnetic field for 48 h, and was dependent upon the field strength. cAMP accumulation in response to PTH is followed by induction of ornithine decarboxylase, a good marker of differentiated chondrocytes, after PTH treatment for 4 h. Consistent with the enhanced cAMP accumulation, ornithine decarboxylase activity induced by PTH was also increased by the pulsed electromagnetic field to 170% of that in cells not exposed to a pulsed electromagnetic field. Furthermore, stimulation of glycosaminoglycan synthesis, a differentiated phenotype, in response to PTH was significantly enhanced by a pulsed electromagnetic field. Thus, a pulsed electromagnetic field enhanced a series of events in rabbit costal chondrocytes in response to PTH. These findings show that exposure of chondrocytes to a pulsed electromagnetic field resulted in functional differentiation of the cells.
Hiraki Y. et.al. Dep. Biochemistry and Calcified-Tissue Metabolism, Faculty of Dentistry, Osaka University, Japan. Biochim Biophys Acta 


Impulse magnetic-field therapy for erectile dysfunction: a double-blind, placebo-controlled study. 

This double-blind, placebo-controlled study assessed the efficacy of 3 weeks of pulsing magnetic-field therapy for erectile dysfunction (ED). In the active-treatment group, all efficacy endpoints were significantly improved at study end (P < or = .01), with 80% reporting increases in intensity and duration of erection, frequency of genital warmth, and general well-being. Only 30% of the placebo group noted some improvement in their sexual activity; 70% had no change. No side effects were reported. 
Pelka R. Et.al. Universitat der Bundeswehr Munchen, Neubiberg/Munich, Germany. 


Comparison of electromagnetic field stimulation on the healing of small and large intestinal anastomoses. 

Magnetic fields have been shown to affect biologic processes. Accordingly, an experimental study was designed to investigate the effect of electromagnetic field therapy on intestinal healing and to compare small and large intestinal anastomoses. Conclusions: Electromagnetic field stimulation provided a significant gain in anastomotic healing in both small and large intestine. The study demonstrated a significant increase in both biochemical and mechanical parameters. 
Nayci A. et.al. Cakmak M, Aksoyek S, Renda N, Yucesan S. Department of Pediatric Surgery, Mersin University Medical Faculty, Turkey. 

 

 

The efficacy of un-united tibial fracture treatment using pulsing electromagnetic fields: relation to biological activity on non-union bone ends. 

Thirty un-united tibial fractures with a median time since injury of 18+/-9 months were treated by electrical stimulation using pulsing electromagnetic field therapy. Union was achieved in 25 cases (83.3%) in a median interval of 8.6+/-3.2 months. Patient age, gender, the presence of surgical hardware, length of disability, and the number of surgical procedures did not affect the outcome. Un-united fractures that appeared to be hypertrophic or sclerotic, indicating a good blood supply to the bone ends, all healed.. Pulsing electromagnetic field therapy is an effective treatment for un-united tibial fractures with good blood supply to the bone ends. 
Ito H. et.al. Department of Orthopaedic Surgery, Nippon Medical School, Tokyo, Japan. 


Ultrastructural study of hyaluronic acid before and after the use of a pulsed electromagnetic field, electrorydesis, in the treatment of wrinkles. 

BACKGROUND. Treatment of wrinkles has become an increasing problem for dermatologists. Hyaluronic acid is a component of the family of glycosaminoglycans (GAGS, substances known for their property of retaining water), that significantly decreases with aging and in wrinkles. A new technique that uses a specific pulsed electromagnetic field, electrorydesis, has been introduced in the treatment of wrinkles associated with aging. The treatment is based on the reported in vitro effects of specific electromagnetic fields on fibroblast cultures (e.g., an increase in DNA synthesis and in the production of collagen and presumably also of GAGS). METHODS. The in vivo effects of the electromagnetic field on aged skin (3 subjects aged 50, 56 and 60 years), with particular focus on the ultrastructural modifications and GAGS amount before and after the treatment, were evaluated by electron microscope. RESULTS. The ultrastructural study (tissue stained with alcian blue) showed after treatment a significant increase (p < 0.005) of the electron-dense granules (corresponding to hyaluronic acid), located in collagen elastic fibers, and in the soluble matrix. This presumably leads to subsequent edema that was clinically evident after the treatment. CONCLUSIONS. These data suggest that the increased levels of GAGS and the subsequent edema of the dermis could explain at least in part the clinical changes observed after electrorydesis treatment (e.g., swelling and "disappearance" of the wrinkle).
Ghersetich I. Et.al. De. of Dermatology, University of Florence, Italy. Int J Dermatol 


Optimization of electric field parameters for the control of bone remodeling: exploitation of an indigenous mechanism for the prevention of osteopenia. 

The discovery of piezoelectric potentials in loaded bone was instrumental in developing a plausible mechanism by which functional activity could intrinsically influence the tissue's cellular environment and thus affect skeletal mass and morphology. Using an in vivo model of osteopenia, we have demonstrated that the bone resorption that normally parallels disuse can be prevented or even reversed by the exogenous induction of electric fields. Importantly, the manner of the response (i.e., formation, turnover, resorption)
is exceedingly sensitive to subtle changes in electric field parameters. Fields below 10 microV/cm, when induced at frequencies between 50 and 150 Hz for 1 h/day, were sufficient to maintain bone mass even in the absence of function. Reducing the frequency to 15 Hz made the field extremely osteogenic. Indeed, this frequency-specific sinusoidal field initiated more new bone formation than a more complex pulsed electromagnetic field (PEMF), though inducing only 0.1% of the electrical energy of the PEMF. The frequencies and field intensities most effective in the exogenous stimulation of bone formation are similar to those produced by normal functional activity. This lends strong support to the hypothesis that endogenous electric fields serve as a critical regulatory factor in both bone modeling and remodeling processes. Delineation of the field parameters most effective in retaining or promoting bone mass will accelerate the development of electricity as a unique and site-specific prophylaxis for osteopenia. Because fields of these frequencies and intensities are indigenous to bone tissue, it further suggests that such exogenous treatment can promote bone quantity and quality with minimal risk or consequence.
Rubin C. Et.al. Dep. Orthopaedics, State University of New York J Bone Miner Res 


Pulsed magnetic fields improve osteoblast activity during the repair of an experimental osseous defect. 

The influence of pulsed low-frequency electromagnetic fields (PEMFs) on bone formation was investigated in studies of the healing process of transcortical holes, bored at the diaphyseal region of metacarpal bones of six adult horses, exposed for 30 days to PEMFs (28 G peak amplitude, 1.3 ms rise time, and 75 Hz repetition rate). A pair of Helmholtz coils, continuously powered by a pulse generator, was applied for 30 days to the left metacarpal bone, through which two holes, of equal diameter and depth, had been bored at the diaphyseal region. Two equal holes, bored at the same level in the right metacarpal and surrounded by an inactive pair of Helmholtz coils, were used as controls. All horses were given an intravenous injection of 25-30 mg/kg of tetracycline chloride on the 15th and again on the 25th day after the operation and were killed 5 days later. The histomorphometric analysis indicated that both the amount of bone formed during 30 days and the mineral apposition rate during 10 days (deduced from the interval between the two tetracycline labels) were significantly greater (p <0.01 and p < 0.0001, respectively) in the PEMF-treated holes than in the controls. As did a previous investigation, these preliminary findings indicate that PEMFs at low frequency not only stimulate bone repair but also seem to improve the osteogenic phase of the healing process, at least in our experimental conditions.
Cane V. et.al. Institute of Human Anatomy, University of Modena, Italy. : J Orthop Res 


Use of pulsed electromagnetic fields in treatment of loosened cemented hip prostheses. A double-blind trial. 

A double-blind trial of pulsed electromagnetic fields (PEMFs) for loosened cemented hip prostheses was conducted at two centers. Of the 40 patients who enrolled, 37 met entry criteria and were available for analysis. All patients completed six months of treatment (either active or control units). Success was determined clinically by a Harris hip score greater than or equal to 80 points (or an increase of ten points if initially greater than or equal to 70 points). Ten of the 19 active units were successes (53%), whereas two of the 18 controls (11%) exhibited a placebo effect, a statistically significant and clinically relevant result. A 60% relapse rate among the active successes was seen at 14 months poststimulation, and despite maintenance therapy of one hour per day, the relapse rate increased to 90% at three years. These data suggest that for loosened cemented hip prostheses, use of PEMFs is a treatment option to delay revision hip surgery.
Kennedy W. et.al. Theda Clark Regional Medical Center, Wisconsin. Clin Orthop 


The effect of low-frequency electrical fields on osteogenesis. 

An in vivo animal model of disuse osteopenia was used to determine the osteogenic potential of specific components of electrical fields. The ability of a complex pulsed electrical field to inhibit loss of bone was compared with the remodeling response generated by extremely low-power, low-frequency (fifteen, seventy-five, and 150-hertz) sinusoidal electrical fields. The left ulnae of thirty adult male turkeys were functionally isolated by creation of distal and proximal epiphyseal osteotomies and then were exposed, for one hour each day, to an electrical field that had been induced exogenously by means of magnetic induction. After a fifty-six-day protocol, the remodeling response was quantified by a comparison of the cross-sectional area of the mid-part of the diaphysis of the functionally isolated ulna with that of the intact contralateral ulna. Disuse resulted in a 13 per cent mean loss of osseous tissue, which was not significantly different than the 10 per cent loss that was caused by disuse treated with inactive coils. Exposure to the pulsed electrical fields prevented this osteopenia and stimulated a 10 per cent mean increase in the bone area. The osteogenic influence of the sinusoidal electrical fields was strongly dependent on the frequency; the 150, seventy-five, and fifteen-hertz sinusoidal fields, respectively, generated a -3 per cent, + 5 per cent, and + 20 per cent mean change in the bone area. These results suggest a tissue sensitivity that is specific to very low-frequency sinusoidal electrical fields and they imply that the induced electrical fields need not have complex waveforms to be osteogenic. Since the frequency and intensity range of the sinusoidal fields producing the greatest osteogenic response are similar to the levels produced intrinsically by normal functional activity, these results support the hypothesis that electricity plays a role in the retention of the normal remodeling balance within mature bone.
McLeod K. et.al. Dep. Orthopaedics, School of Medicine, State University of New York, : J Bone Joint Surg Am 


Treatment of ununited tibial fractures: a comparison of surgery and pulsed electromagnetic fields (PEMF). 

The use of pulsed electromagnetic fields (PEMF) is gaining acceptance for the treatment of ununited fractures. The results of 44 articles published in the English language literature have been compiled to assess the effectiveness of PEMF vs surgical therapy. For ununited tibial fractures, 81% of reported cases healed with PEMF vs 82% with surgery. After multiple failed surgeries, the success rate of PEMF is reported to be greater than with surgery; this discrepancy increases with additional numbers of prior surgeries. In infected nonunions, the results of surgical treatment decreased by 21% and were less than the results utilizing PEMF (69% vs 81%). In open fractures, surgical healing exceeded PEMF (89% vs 78%), whereas in closed injuries PEMF cases healed more frequently (85% vs 79%). In general, PEMF treatment of ununited fractures has proved to be more successful than noninvasive traditional management and at least as effective as surgical therapies. Given the costs and potential dangers of surgery, PEMF should be considered an effective alternative. Experience supports its role as a successful method of treatment for ununited fractures of the tibia.
Gossling H. Et.al. Dep. Orthopedic Surgery, University of Connecticut Orthopedics 


Long-term pulsed electromagnetic field (PEMF) results in congenital pseudarthrosis. 

Ninety-one patients with congenital pseudarthrosis of the tibia have been treated with pulsed electromagnetic fields (PEMFs) since 1973 and all except 4 followed to puberty. Lesions were stratified by roentgenographic appearance. Type I and type II had gaps less than 5 mm in width. Type III were atrophic, spindled, and had gaps in excess of 5 mm. Overall success in type I and II lesions was 43 of 60 (72%). Of those 28 patients seen before operative repair had been attempted, 7 of 8 type I lesions healed (88%), whereas 16 of 20 type II lesions healed (80%) on PEMFs and immobilization alone. Only 19% (6 of 31) type III lesions united, only one of which did not require surgery. Sixteen of 91 limbs (18%) were ultimately amputed, most before treatment principles were fully defined in 1980. Fourteen of these 16 patients (88%) had type III lesions. Refracture occurred in 22 patients, most as the result of significant trauma, in the absence of external brace support. Twelve of the 19 refractures, retreated with PEMFs and casts, healed on this regime. Episodic use of PEMFs proved effective in controlling stress fractures in several patients until they reached puberty. PEMFs, which are associated with no known risk, appear to be an effective, conservative adjunct in the management of this therapeutically challenging, congenital lesions.
Bassett C. et.al. Bioelectric Research Center, Riverdale, New York Calcif Tissue Int 


Protection against focal cerebral ischemia following exposure to a pulsed electromagnetic field. 

There is evidence that electromagnetic stimulation may accelerate the healing of tissue damage following ischemia.. Exposure to pulsed electromagnetic field attenuated cortical ischemia edema on MRI at the most anterior coronal level by 65% (P < 0.001). On histologic examination, PEMF exposure reduced ischemic neuronal damage in this same cortical area by 69% (P < 0.01) and by 43% (P < 0.05) in the striatum. Preliminary data suggest that exposure to a PEMF of short duration may have implications for the treatment of acute stroke.
Grant G. et.al. Department of Neurosurgery, Stanford University, California

 

 

Modulation of bone loss during disuse by pulsed electromagnetic fields. 

The effect of pulsed electromagnetic fields (PEMFs) on bone loss associated with disuse was investigated by applying 1.5 Hz repetitions of 30 ms bursts of asymmetric pulses, varying from +2.5 to -135 mV, to bones deprived of their normal functional loading. The proximal portion of one fibula in each of a group of ovariectomised adult female beagle dogs was isolated from functional loading in vivo by proximal and distal osteotomies. Comparison of these prepared bones with their intact contralateral controls after 12 weeks, showed a 23% reduction in cross-sectional area. In similarly prepared bones exposed to PEMFs for 1 h per day, 5 days per week, this bone loss was substantially and significantly reduced to 9% (p = 0.029). There was no evidence of any new bone formation on the periosteal surface of prepared fibulae in treated or untreated situations. PEMF treatment was not associated with any significant change in number of osteons per mm2 formed within the cortex of the bones, their radial closure rate, or their degree of closure. The modulation in loss of bone area associated with exposure to PEMFs can, therefore, be inferred to be due to a reduction in resorption on the bone surface.
Skerry T. et.al. Dep. of Anatomy, University of Bristol, U.K. J Orthop Res 


Treatment of chronic varicose ulcers with pulsed electromagnetic fields: a controlled pilot study. 

To evaluate the efficacy of pulsed electromagnetic fields (PEMF) in healing of chronic varicose ulcers, 19 patients with this condition were included in a double-blind controlled clinical trial. All patients received standard ulcer therapy throughout the duration of the study and were randomly divided into two groups to receive either active or inactive PEMF therapy. Active therapy was provided by the use of a pait of Helmholtz coils on a twice weekly basis over a five week period and inactive therapy was provided on an identical regimen with identical coils wound so that no magnetic field was produced when an electric current was passed through them. The clinician and patients were unable to distinguish the active or inactive coils. No statistically relevant difference was noted between the two groups in the healing rates of the ulcer, change in the lower leg girth, pain or infection rates. However there was a trend in favour of a decrease in ulcer size and lower leg girth in the group treated with active PEMF. As PEMF is a novel treatment for chronic varicose ulcers, more work needs to be done to establish treatment parameters and its usefulness in the treatment of this condition.
Todd D. et.al. Dep. Dermatology, Belfast City Hospital. Ir Med J 


Low energy high frequency pulsed electromagnetic therapy for acute whiplash injuries. A double blind randomized controlled study. 

The standard treatment of acute whiplash injuries (soft collar and analgesia) is frequently unsuccessful. Pulsed electromagnetic therapy PEMT has been shown to have pro-healing and anti-inflammatory effects. This study examines the effect of PEMT on the acute whiplash syndrome. PEMT as described is safe for domiciliary use and this study suggests that PEMT has a beneficial effect in the management of the acute whiplash injury. 
Foley-Nolan D. et.al. Mater Hospital, Dublin, Ireland. 


Bone density changes in osteoporosis-prone women exposed to pulsed electromagnetic fields (PEMF). 

To determine the effect of a 72 Hz pulsating electromagnetic field (PEMF). Bone mineral densities of the treated radii measured by single-photon densitometry increased significantly in the immediate area of the field during the exposure period and decreased during the following 36 weeks. The data suggest that properly applied PEMF, if scaled for whole-body use, may have clinical application in the prevention and treatment of osteoporosis. 
Tabrah F. et.al. University of Hawaii School of Medicine, Honolulu. 


Effect of pulsed magnetic fields on human umbilical endothelial vein cells  

The long-term goal of this program was to examine the efficacy of electromagnetic fields as an adjunct therapy to facilitate wound repair. The experiments reported here were directed to the question of whether pulsed electromagnetic fields (PEMF) could facilitate endothelial cell migration following induction of a wound. These studies were based on a report that weak PEMF facilitated cell migration in a wounded confluent monolayer culture of human umbilical vein cells. Experiments reported in this paper were an attempt to reproduce and extend these observations. Our data support the original observations. Further, we examined several hypotheses in an attempt to clarify the mechanism of interaction between the applied electromagnetic fields and cells. The data do not support the hypothesis that PEMF is acting in a manner similar to endothelial cell-growth factor, a normal component of the growth medium, or that PEMF applied at the time of cell transfer enhance DNA replication. We have found that PEMF is more effective in accelerating migration if they induce an electric field that is perpendicular rather than parallel to the sides of the wound. 
Goodman, E. et.al J. Biomedical Res. Inst., Univ. Wisconsin, WI, USA 

Effects of pulsed magnetic fields in the therapy of osteoporosis induced by ovariectomy in the rat.  

This paper presents preliminary results on the effects of pulsed electromagnetic fields (EMF) in the therapy of post menopausal osteoporosis induced by ovariectomy in female rats aged ten months. In particular, the effects of the intensity of pulsed EMF applied at constant frequency has been studied. Magnetic fields pulsed at 50 Hz were used having a positive sinusoidal wave form with a maximum intensity of 30 and 70 Gauss. Treatment lasting one hour per day for 4 months showed that the pulsed EMF with 30 Gauss of maximum intensity are able to slow down the bone mass loss, keeping it within some 10%; with pulsed EMF with 70Gauss of maximum intensity, instead, no significant bone mass loss was observed. 
Zati, A.et.al. Institute Orthopaedic Rizzoli, University of Bologna. 


Possible therapeutic applications of pulsed magnetic fields 

Magnetotherapy is a relatively new, nowadays however, relatively widespread method in several medical disciplines. The mechanism proper of the favorable action of the pulsed magnetic field on the living organism is not quite clear so far, clinical investigations revealed, however, a favorable anti-inflammatory, angioedematous and analgesic therapeutic effect. The authors sought an optimal frequency of the pulsed magnetic field with regard to the character of the disease. They focused attention above all on treatment of acute and chronic inflammatory conditions of the locomotor apparatus, ischaemia of the blood vessels of the lower extremities, dyspeptic syndrome, lactation mastitis and other diseases. One therapeutic cycle lasted 20 minutes, the mean number of cycles varied between 5.8 and 7.7. A regression of complaints was recorded as a rule after 2-3 sessions. The optimal frequency of the pulsed magnetic field seems to be a value between 10.0 and 25.0 Hz. It is useful in particular in severe conditions to repeat the therapeutic cycle after 2-3 months. The advantage of this therapeutic method is the minimal number of contraindications. 
Navratil, L. et.al.  Czech Republic 


The Canadian experience with pulsed magnetic fields in the treatment of un-united tibial fractures 

A clinical survey of 56 patients was conducted at four different centers in Canada to evaluate the effect of extremely low frequency pulsed magnetic fields (PMF) on un-united fractures of the tibia. All ten patients with delayed union and 84% of the 44 patients with non-union healed. One case with a traumatic pseudarthrosis and one with a congenital pseudarthrosis failed to respond to treatment. These results compare favorably to those reported by others using a system with different pulse characteristics. Prolonged immobilization is necessary and poses problems of rehabilitation. Non-unions with a gap between the tibial fragments and pseudarthroses are better treated with bone grafting and internal fixation prior to electrical stimulation. 
Haas, W. et.al. J. of Clin. Orthop.