Electromagnetic Field Therapies: A Bibliography from Medline

Phil Rogers MVB MRCVS
1, Esker Lawns, Lucan, Dublin, Ireland
e-mail : philrogers@tinet.ie

1. Bone and Joint

1a. Bone problems, fractures, psedoarthrosis

Crawford AH (1986) Neurofibromatosis in children. Acta Orthop Scand Suppl 218:1-60. Clinical diagnosis of neurofibromatosis in childhood usually is based on the presence of numerous cafe-au-lait spots. Early diagnosis allows for continuing follow-up and appropriate counselling. Symptomatic therapy can be provided if necessary. The disorder has a tendency via its mesodermal route to affect almost every system in the body; however, few laymen have even heard of the disorder and, except for the "Elephant Man" notoriety, are totally unaware of it, whereas muscular dystrophy, cystic fibrosis, and Down syndrome although occurring less frequently are well known to the general public. The management of neurofibromatosis in children covers an extremely wide spectrum: at times the management seems to be simple, involving little more than clinical evaluation and simple investigations. However, in view of the protean manifestations of the condition, a complete history including family history is obligatory, and investigation must include radiographic studies of the abdomen, chest, spine, and skull, the latter to include special views of the orbits and optic foramina. My investigation of this disorder has been extremely frustrating because of the progressive character of the disease. Nothing seems to alter the natural course of the disease. I cannot say that my investigative efforts have revealed any breakthroughs in treatment. An aggressive surgical approach to the myriad of lesions associated with this disease, especially neuromata or segmental problems, is probably advisable. The early treatment of tibial pseudarthrosis by polyprophylene orthotic and pulsating EMFs shows encouraging results over the short course, although I am not so sure as to whether or not the patients would do as well with the custom fit orthotic with or without the electronics. Early stabilization of spinal deformity has proven to be more than moderately successful and is strongly recommended after appropriate intraspinal evaluation. The management of tumors of the brain and spinal cord, as well as those associated with limb hypertrophy and congenital tibial pseudarthrosis, is undergoing innovations at this time which may result in a better cure rate. Procedures include the use of CT to evaluate tumors [Coleman et al. have attempted to differentiate neurofibroma from neurofibrosarcoma by contrast enhancement methods], the use of CO2 lasers to remove previously inoperable CNS tumors, microvascular bone transplantation and pulsating EMF to treat pseudarthrotic bones. PMID: 3083645, UI: 86182808

Alexa O (1996) [Electrically induced osteogenesis. II. Experimental studies - Article in Romanian]. Rev Med Chir Soc Med Nat Iasi Jan;100(1-2):62-65. Disciplina de Ortopedie, Facultatea de Medicina, Universitatea de Medicina si Farmacie Gr. T. Popa, Iasi. The paper presents the possibilities to induce osteogenesis using different types of electrical current. The direct current may be used with invasive or semi-invasive methods. Electrodes are placed internally, near the bone. Experiments showed that the optimum stimulation is achieved with current between 5 and 20 uA. The capacitive current is able to induce osteogenesis. The electrodes are placed externally; between the electrodes there is an electric field with the value ranged 1-10 mV/cm. The method of PEMFs is based on the field produced by a coil placed externally. The magnetic field range between 0, 1 and 20 Gauss. This is the most appreciate method because is noninvasive and offered the best experimental results. Publication Types: Review Review, tutorial PMID: 9455398, UI: 98116576

Auer JA, Burch GE, Hall P (1983) Review of pulsing EMF therapy and its possible application to horses. Equine Vet J Oct;15(4):354-360. Relevant literature on electrostimulation in general, and PEMFs in particular, is reviewed. DC current influences cell behaviour by affecting transmembrane ion transport, which is often under enzymatic control. PEMFs influence cell functions through adsorption of ions or dipole formation at the cell membrane. Invasive and non-invasive DC current stimulation is compared to PEMFs. The mode of application of PEMFs to the equine limb and suggested treatment times are briefly discussed. 2 case reports are used to illustrate the effect of PEMFs in equine fracture treatment. PMID: 6641683, UI: 84057661

Barker AT, Dixon RA, Sharrard WJ, Sutcliffe ML (1984) Pulsed magnetic field therapy for tibial non-union: Interim results of a double-blind trial. Lancet May 5;1(8384):994-996. Patients with tibial fractures which had remained ununited for at least 52 wk were randomly allocated to either active or dummy pulsed magnetic field stimulators and treated in full leg plasters for 24 wk with a non-weightbearing conservative regimen, as is usual with such techniques. Fractures in 5/9 patients with working machines united and fractures in 5/7 patients with dummy machines also united. These early results of this double-blind trial are compatible with a difference in success rate at 24 wk on active treatment of +33% to -61% (95% confidence limits) compared with the success rate on the dummy stimulators. The high proportion of fractures uniting in the control group suggests that conservative management of non-union is effective and this may explain much of the success attributed to pulsed magnetic field therapy. Publication Types: Clinical trial Randomized controlled trial PMID: 6143970, UI: 84190306

Bassett CA, Schink-Ascani M (1991) Long-term pulsed EMF (PEMF) results in congenital pseudarthrosis. Calcif Tissue Int Sep;49(3):216-220. Bioelectric Research Ctr, Riverdale, New York 10463. 91 patients with congenital pseudarthrosis of the tibia were treated with PEMFs since 1973; 87 were followed to puberty. Lesions were stratified by roentgenographic appearance. Type I and type II had gaps less <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 43/60 (72%). Of those 28 patients seen before operative repair had been attempted, 7/8 type I lesions healed (88%), whereas 16/20 type II lesions healed (80%) on PEMFs and immobilization alone. Only 19% (6/31) type III lesions united, only one of which did not require surgery. 16/91 limbs (18%) were ultimately amputed, most before treatment principles were fully defined in 1980. 14 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. 12/19 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, seem to be an effective, conservative adjunct in the management of this therapeutically challenging, congenital lesions. PMID: 1933587, UI: 92034339

Bassett CA (1993) Beneficial effects of EMFs. J Cell Biochem Apr;51(4):387-393. Bioelectric Research Ctr, Columbia Univ, Riverdale, New York 10463. Selective control of cell function by applying specifically configured, weak, time-varying magnetic fields has added a new, exciting dimension to biology and medicine. Field parameters for therapeutic, PEMFs were designed to induce voltages similar to those produced, normally, during dynamic mechanical deformation of connective tissues. As a result, a wide variety of challenging musculoskeletal disorders have been treated successfully over the past 20 yr. >250000 patients with chronically ununited fractures have benefitted, worldwide, from this surgically non-invasive method, without risk, discomfort, or the high costs of operative repair. Many of the athermal bioresponses, at the cellular and subcellular levels, have been identified and found appropriate to correct or modify the pathologic processes for which PEMFs have been used. Not only is efficacy supported by these basic studies but by a number of double-blind trials. As understanding of mechanisms expands, specific requirements for field energetics are being defined and the range of treatable ills broadened. These include nerve regeneration, wound healing, graft behavior, diabetes, and myocardial and cerebral ischemia (heart attack and stroke), among other conditions. Preliminary data even suggest possible benefits in controlling malignancy. Publication Types: Review Review, tutorial PMID: 8496242, UI: 93266659

Bassett CA, Mitchell SN, Gaston SR (1982) Pulsing EMF treatment in ununited fractures and failed arthrodeses. JAMA Feb 5;247(5):623-628. PEMFs induce weak electric currents in bone by external coils on casts or skin. In November 1979, the FDA approved this surgically noninvasive, outpatient method. It produced confirmed end results in 1007 ununited fractures and 71 failed arthrodeses, worldwide. Overall success was 81% at Columbia-Presbyterian Med Ctr, 79% internationally and 76% in other patients in the USA. PEMF therapy was effective in 75% of 332 patients (a subset) with an average 4.7-yr disability duration, an average of 3.4 previous operative failures to produce union, and a 35% rate of infection. 84% of carpal naviculars and 82% of femoral neck-trochanteric non-unions were united. After attempted arthrodeses could not salvage a failed total-knee prosthesis, PEMFs promoted healing in 85% of patients. When coils were unsuccessful alone, combining them with surgical repair was effective. PMID: 7054564, UI: 82101246

Blumlein H, Schneider U, Rahn BA, Perren SM (1977) [The effect of so-called electrodynamic potentials on experimental reaction-poor pseudarthrosis - Article in German]. Chir Forum Exp Klin Forsch Apr;:105-108. The effect of the magnetic field and the alternating current according to the Kraus-Lechner model was investigated on experimental pseudarthroses in beagle dogs. The evaluation of 16 pseudarthroses showed no effect of the method Kraus-Lechner on healing. PMID: 312722, UI: 79190830

Boening KJ (1983) [Treatment of a navicular bone fracture in a horse with pulsing EMF - Article in German]. Tierarztl Prax 11(4):483-486. PMID: 6658771, UI: 84098412

Brighton CT, Pollack SR (1985) Treatment of recalcitrant non-union with a capacitively coupled electrical field: A preliminary report. J Bone Joint Surg [Am] Apr;67(4):577-585. 22 well established non-unions in 20 patients were treated with a capacitively coupled electrical signal (sine wave, 60 KHz, 5 V peak to peak) that was applied non-invasively through stainless-steel capacitor plates placed on the skin surface overlying the approximate site of the non-union. The average age of the 11 female and 9 male patients in this series was 38.4 yr, and the average duration of the 22 non-unions was 3.3 yr. 17 of the non-unions were labeled recalcitrant, meaning that they had failed to heal after either previous bone-grafting or another type of electrical stimulation, or both. 5 of the non-unions had not been previously treated. 17 (77.3%) of the non-unions achieved solid osseous union after an average of 22.5 wk of treatment with capacitive coupling. The results in this small series were not affected by the non-union being recalcitrant, by the fact that 1 patient bore full weight on the extremity in a cast, by the presence of osteomyelitis, or by the presence of remaining metallic internal-fixation devices in the bone. Since capacitive coupling is non-invasive, involves portable equipment, allows full weight-bearing on the lower extremity in a cast, is easy to apply, and does not require precise localization of the capacitor plates, it has distinct advantages over other methods of treating non-union with electricity. PMID: 3872300, UI: 85157654

Cakirgil GS, Saplakoglu A, Yazar T (1989) The compared effect of a four-coiled system in pulsed EMF stimulation. Orthopedics Nov;12(11):1481-1484. Dept of Orthopedics, Univ of Ankara, Yenisehir, Turkey. A clinical trial evaluated the effects of a pulsed magnetic field on pseudoarthroses of in cases. 19/21 cases had successful results; the remaining 2 failed to respond. 2-coiled and 4-coiled systems were used in this study. The 4-coiled system was more effective in spite of its practical disadvantages and larger size. Publication Types: Clinical trial PMID: 2685789, UI: 90068246

Capanna R, Donati D, Masetti C, Manfrini M, Panozzo A, Cadossi R, Campanacci M (1994) Effect of EMFs on patients undergoing massive bone graft following bone tumor resection: A double blind study. Clin Orthop Sep;306:213-221. Istituto Ortopedico Rizzoli, Clinica Ortopedica I, Universita di Bologna, Italy. Massive bone allograft after tumor resection has been used for >20 yr. Many factors negatively influence the healing of the junction between the allograft and the host bone, resulting in a low healing rate and lengthy time to union. This study evaluated whether PEMF stimulation could be advantageously used in these patients. A double blind prospective randomized study was designed. 83 host graft junctions in 47 patients were considered. The overall host graft junction healing rate was the same (67%) in both control and active stimulated patients. Although not statistically significant, a positive effect of PEMFs was seen for those host graft junctions with a cortico-cortical contact between allograft and host bone. When adjuvant postoperative chemotherapy was not used, a definite effect of PEMF stimulation was seen: the healing time decreased from 9.4 mo in the control group to 6.7 mo in the active stimulated group (p<.001). This effect would have been lost if chemotherapy was employed. There was also no advantage in supplement with iliac crest autografts at the host graft junction site if chemotherapy was used. Factors that significantly influenced the host graft junction healing rate were: chemotherapy; type of allograft host bone contact; quality of host graft junction; and, in intercalary allografts, use of the osteosynthesis device. No difference was noted between control and active groups for patient survival or number of local or distal tumor recurrences. Publication Types: Clinical trial Randomized controlled trial PMID: 8070199, UI: 94349691

Chen II, Saha S (1987) Analysis of the current distribution in bone produced by pulsed electro-magnetic field stimulation of bone. Biomater Artif Cells Artif Organs 15(4):737-744. Dept of Physiology and Biophysics, Louisiana State Univ Med Ctr, Shreveport 71130. Pulsed EM stimulation is being increasingly used by orthopaedic surgeons to treat non-unions and congenital pseudoarthrosis. In this paper a theoretical model is developed to analyze the distribution of induced current in bone due to a PEMF, produced by a pair of Helmholtz coils. The result shows that the induced current density is dependent of the electrical properties of bone, geometry of the coils and their location. PMID: 3452430, UI: 88252360

Darendeliler MA, Darendeliler A, Sinclair PM (1997) Effects of static magnetic and pulsed EMFs on bone healing. Int J Adult Orthodon Orthognath Surg 12(1):43-53. Discipline of Orthodontics, Faculty of Dentistry, Univ of Sydney, Australia. The purpose of the present study was to evaluate the healing pattern of an experimentally induced osteotomy in Hartley guinea pigs in the presence of static magnetic and PEMFs. The sample consisted of 30 Hartley guinea pigs 2 wk of age divided into 3 groups: pulsed EM, static magnetic, and control. An osteotomy was performed in the mandibular postgonial area in all groups under general anesthesia. During the experimental period of 9 d, the animals were kept in experiment cages 8 h/d, the first two groups being in the presence of pulsed EM and static magnetic field, respectively. Based on histologic results, both static and PEMFs seemed to accelerate the rate of bone repair when compared to the control group. The osteotomy sites in the control animals consisted of connective tissue, while new bone had filled the osteotomy areas in both magnetic field groups. PMID: 9456617, UI: 98117733

de Barros Filho TE, Rossi JD, Lage L de A, Rodrigues CJ, de Oliveira AS, Pinto FC, dos Reis GM, Rodrigues Junior AJ (1992) [Effect of EMFs on osteogenesis: an experimental study on rats - Article in Portugese]. Rev Hosp Clin Fac Med Sao Paulo May;47(3):128-130. LIM-41, Instituto de Ortopedia e Traumatologia, Hospital das Clinicas, Faculdade de Medicina, Universidade de Sao Paulo. The authors studied experimentally the PEMF effects in an experimental model in rats, for evaluation of the velocity of consolidation of tibial and fibular fractures. The animals were followed for a period of 3 wk under continuous stimulation and there were done radiological evaluation weekly and histological study at the end of the study. There were no histological, clinical or radiological differences between the group of rats submitted to PEMFs and the control group. PMID: 1340586, UI: 94053290

Deibert MC, Mcleod BR, Smith SD, Liboff AR (1994) Ion resonance EMF stimulation of fracture healing in rabbits with a fibular ostectomy. J Orthop Res Nov;12(6):878-885. Dept of Orthopaedics and Rehabilitation, Univ of Vermont College of Med, Burlington 05405. Rabbits with a fibular ostectomy were exposed for 28 d to magnetic fields that satisfied the ion resonance conditions for calcium or magnesium. The rabbits were exposed to whole body treatment for 1/2 h, 3 h, or 24 h/d. The fibulae from the experimental and control animals were removed surgically and were subjected to force-deflection testing to establish the stiffness of the healed fracture. The fibulae from the rabbits exposed to the ion resonance magnetic fields were found to be 55-299% (p<.01) more robust than the fibulae from the control animals. PMID: 7983563, UI: 95074712

Diusembaev AA, Diusembaev KA, Zhakupbaev AA (1991) [Experience in the treatment of open fractures of shin bones by means of bitemporal ultra-high frequency electric field and transcerebral electrophoresis - Article in Russian]. Ortop Travmatol Protez Sep;9:43-44. PMID: 1780146, UI: 92140833

Fox IM, Smith SD (1983) Bioelectric repair of metatarsal non-unions. J Foot Surg 22(2):108-115. An exciting new development in the field of bone physiology has been the discovery of electrical potentials in stressed bone and the relation of this knowledge to Wolff's law. The application of these discoveries for the treatment of non-unions by exogenous bioelectric potentials via direct current and PEMFs has been a major development in orthopedic surgery. To date, the literature reports the use of this new treatment modality in the large long bones of the extremities. The authors have utilized these techniques to repair non-unions of the metatarsals and, in the process, have adapted some of the principles for the small bones of the foot. PMID: 6602827, UI: 83239598

Frykman GK, Taleisnik J, Peters G, Kaufman R, Helal B, Wood VE, Unsell RS (1986) Treatment of nonunited scaphoid fractures by pulsed EMF and cast. J Hand Surg [Am] May;11(3):344-349. 35/44 nonunited scaphoid fractures that were at least 6 mo old healed in a mean time of 4.3 mo during PEMF treatment using external coils and a thumb spica cast. The mean time from the onset of the fracture to treatment was 40 mo. No concurrent operation was performed. Follow-up time averaged 8.4 mo. 8/9 fractures with avascular necrosis healed. 5/8 fractures in the proximal third healed. 12/16 patients (75%) treated in short-arm thumb spica casts and PEMF healed versus 22 (92%) of 24 patients treated initially in long-arm thumb spica casts and PEMF. We have found PEMF to be a reliable alternative method of treating nonunited scaphoid fractures. Because of the low risk, simplicity of use, and reliability, we recommend its consideration in the treatment of undisplaced, nonunited fractures without carpal instability <5 yr after the injury. Treatment should initially begin with a long-arm cast. PMID: 3711607, UI: 86225254

Gupta TD, Jain VK, Tandon PN (1991) Comparative study of bone growth by pulsed EMFs. Med Biol Eng Comput Mar;29(2):113-120. Dept of Electrical Engineering, Harcourt Butler Technological Institute, Kanpur, India. PEMFs have been widely used for treatment of non-united fractures and congenital pseudarthrosis. Several electrical stimulation systems such as air-cored and iron-cored coils and solenoids have been used the world over and claimed to be effective. Electrical parameters such as pulse shape, magnitude and frequency differ widely, and the exact bone-healing mechanism is still not clearly understood. The study attempts to analyse the effectiveness of various parameters and suggests an optimal stimulation waveform. Mathematical analysis of electric fields inside the bone together with Fourier analysis of induced voltage waveforms produced by commonly used electrical stimulation wave-forms has been performed. A hypothesis based on assigning different weightings to different frequencies for osteogenic response has been proposed. Using this hypothesis astonishingly similar effective values of electric fields have been found in different systems. Effective electric field rather than peak electric field was the main parameter responsible for osteogenesis. The results agree with experimental findings made on human beings by different investigators. PMID: 1857114, UI: 91311997

Hart FX (1994) Spreadsheet method for calculating the induced currents in bone-fracture healing by a low-frequency magnetic field. Bioelectromagnetics 15(5):465-482. Dept of Physics, Univ of the South, Sewanee, Tennessee 37383-1000. A commercially available spreadsheet program is used on a PC to calculate the induced current density and electric field patterns produced in a nonhomogeneous, anisotropic model of tissue by a localized, low-frequency magnetic field source. Specific application is made to coils used to promote the healing of bone fractures in limbs. The variation of the conductivity of the fracture gap during healing causes the induced current density pattern to change correspondingly, whereas the induced electric field remains relatively unchanged. Use of more simplified, isotropic models for bone and soft tissue gave significantly different results from those obtained from the full model. The magnetic field beyond the region of the coils contributes little to the induced currents in the fracture gap if the gap is located near the center of the coils. PMID: 7802713, UI: 95101018

Haupt HA (1984) Electrical stimulation of osteogenesis. South Med J Jan;77(1):56-64. The three electrical stimulation systems available for treating non-union of long bones are successful in approximately 85% of cases. The percutaneous direct current bone growth stimulator is partially invasive, allows patient mobility, can be used with magnetic fixation devices, and can be monitored for proper function, but it requires an operation, cannot be used where infection exists, and is subject to breakage. The implantable direct current bone growth stimulator is similar, but is totally invasive. The external PEMF bone growth stimulator is noninvasive and can be used where infection exists, but it requires long, exact patient compliance and cannot be used with magnetic fixation devices or at certain sites. None of the systems can be used where synovial pseudarthrosis or a sizeable gap between bone ends exists, nor are they more effective than bone grafting. Whether their use might evoke malignant transformation or might accelerate or retard epiphyseal growth patterns is not known. Many controlled studies are needed before it is clear how commonly electrical stimulation should be used to treat bony ununion. Publication Types: Review PMID: 6364371, UI: 84121514

Heckman JD, Ingram AJ, Loyd RD, Luck JV Jr, Mayer PW (1981) Non-union treatment with pulsed EMFs. Clin Orthop Nov;161:58-66. Noninvasive, PEMF treatment, when properly employed, was effective in securing healing of ununited fractures in 64.4% of 149 patients. The effectiveness of this modality can be ascertained after 3 mo of intensive use in >85% of patients, thus enabling the clinician to decide to terminate treatment, continue electrostimulation, or abandon it in favor of another treatment modality. The success of treatment is dependent upon certain variables. Anatomic location of the non-union is important. Higher healing rates were noted in the tibia than in the femur or humerus. In some conditions, combined electrostimulation and bone grafting was more effective than either measure alone. Young patients healed more rapidly than older patients. Electrostimulation is more effective when instituted within 2 yr of the original fracture than when started at longer intervals after the injury. Infection, either quiescent or actively draining, does not seem to affect the overall results. Of greatest importance is patient adherence to the treatment protocol as outlined, with emphasis placed on adequate immobilization of the fracture and absolute nonweight-bearing during treatment. Considering these factors and in light of the very rare frequency of short-term side effects, the use of PEMFs seems to be a reasonable choice of treatment in the management of ununited fractures. PMID: 6975692, UI: 82071043

Heermeier K, Spanner M, Trager J, Gradinger R, Strauss PG, Kraus W, Schmidt J (1998) Effects of extremely low frequency EMF on collagen type I mRNA expression and extracellular matrix synthesis of human osteoblastic cells. Bioelectromagnetics 19(4):222-231. Institut fur Molekulare Virologie, GSF-Forschungszentrum fur Umwelt und Gesundheit, Neuherberg, Germany. Human osteoblastic cells were grown in a 3-D cell culture model and used to test the effects of a 20 Hz sinusoidal EMF (6 mT and 113 mV/cm max) on collagen type I mRNA expression and extracellular matrix formation in comparison with the effects of growth factors. The cells were isolated from trabecular bone of a healthy individual (HO-197) and from a patient presenting with myositis ossificans (MO-192) and grown in a collagenous sponge-like substrate. Maximal enhancement of collagen type I expression after EMF treatment was 3.7-fold in HO-197 cells and 5.4-fold in MO-192 cells. Similar enhancement was found after transforming growth factor-beta (TGF-beta) and insulin-like growth factor-I (IGF-I) treatment. Combined treatment of the cells with EMF and the two growth factors TGF-beta and IGF-I did not act synergistically. MO-192 cells produced an osteoblast-characteristic extracellular matrix containing collagen type I, alkaline phosphatase, and osteocalcin, together with collagen type III, TP-1, and TP-3, two epitopes of an osteoblastic differentiation marker. The effects of EMFs on osteoblastic differentiation were comparable to those of TGF-beta and IGF-I. EMF effects in the treatment of skeletal disorders and in orthopedic adjuvant therapy were mediated via enhancement of collagen type I mRNA expression, which may lead to extensive extracellular matrix synthesis. PMID: 9581965, UI: 98241121

Hinsenkamp M, Ryaby J, Burny F (1985) Treatment of non-union by pulsing EMF: European multicenter study of 308 cases. Reconstr Surg Traumatol 19:147-151. Publication Types: Clinical trial PMID: 3887518, UI: 85191823

Kold SE, Hickman J, Meisen F (1987) Preliminary study of quantitative aspects and the effect of pulsed EMF treatment on the incorporation of equine cancellous bone grafts. Equine Vet J Mar;19(2):120-124. The quantitative aspects of equine cancellous bone graft incorporation and the possibility of influencing graft incorporation by daily exposure to a PEMF was studied in 8 yearling ponies. In order to be able to quantify formative aspects of graft remodelling, a double and treble tetracycline intravital labelling technique was used. Intravital radiographs were obtained at regular intervals throughout the trial, but were found to be of little assistance in assessing any differences between stimulated and non-stimulated grafts. The ponies were humanely destroyed at regular intervals between 9 and 241 d after installation of the graft. Light microscopy and fluorescent light microscopy were used to evaluate quantitative aspects of graft incorporation and to compare PEMF-stimulated grafts with control grafts. There was a small but statistically significant effect of PEMF-stimulation on cancellous bone graft incorporation. In view of this, these observations can only be considered as indicative of a possible trend, but should encourage further studies using different signal modalities. PMID: 3552658, UI: 87190286

Konrad K, Sevcic K, Foldes K, Piroska E, Molnar E (1996) Therapy with pulsed EMFs in aseptic loosening of total hip protheses: a prospective study. Clin Rheumatol Jul;15(4):325-328. Orszagos Reumatologiai es Fizioterapias Intezet, Budapes, Hungary. Aseptic loosening is the most common problem of hip arthroplasties, limiting its long term success. We report a study of PEMF treatment in 24 patients with this complication. At the end of treatment, 6 and 12 mo later, pain and hip movements improved significantly with the exception of flexion and extension. There was significant improvement in both isotope scans and ultrasonography, but not in plain X-ray. The decreased pain and improved function suggest that PEMF is effective in improving symptoms of patients with loose hip replacement. No improvement, however, can be expected in patients with severe pain due to gross loosening. PMID: 8853163, UI: 97005864

Kraus W (1984) [Magnetic field therapy and magnetically induced electrostimulation in orthopedics - Article in German]. Orthopade Apr;13(2):78-92. PMID: 6203080, UI: 84220956

Lechner F, Oeller G, Ascherl R (1979) [Treatment of infected pseudoarthroses with electrodynamic field therapy - Article in German]. Fortschr Med May 24;97(20):943-949. They described the method and fundamentals of electrodynamic field therapy of infected, atrophic pseudarthrosis. Transplantation of autologous spongious bone is of special importance, in addition to the common principles of treatment. The bone graft reestablishes normal electrical conduction within the pseudarthrosis and consolidates the defect as a reactive receptor for the applied AC-potentials. Using this method, we treated 271 patients, suffering from pseudarthroses over an 8-yr period; 91 of them had an infected, often atrophic pseudarthrosis. Bony healing was achieved in 92% of the cases in each group. PMID: 376415, UI: 79192707

Li M (1992) [Electrical stimulation in the treatment of osteoporosis in sciatic denervated rat tibia - Article in Chinese]. Chung Hua Wai Ko Tsa Chih Aug;30(8):458-460. Changhai Hospital, Second Military Med Univ, Shanghai. Osteoporosis in the sciatic-denervated rat tibia was reversed with a capacitively coupled electrical field. In the reversal of a previously established osteoporosis, a statistically significant enhancement of wet weight, dry weight, ashed weight, ultimate strength, cortical area, cortical thickness and a concomitant decrease in cortical porosity occurred in the stimulated, denervated tibiae of the experimental animals compared with the nonstimulated, denervated tibiae of the control animals. A 60 Hz symmetrical sinewave signal was effective in reversing osteoporosis at 10 V peak to peak. Reversal of a well-established osteoporosis in lab animals has not been reported previously. PMID: 1307307, UI: 93339245

Liu HQ, Zhu X, Zhao SL, Yu M, Meng XM (1984) Preliminary report on experimental observation of the effects of magnetic field and "Natural Copper" on fracture healing. Acta Acad Med Wuhan 4(4):220-228. PMID: 6527846, UI: 85138998

Luben RA (1991) Effects of low-energy EMFs (pulsed and DC) on membrane signal transduction processes in biological systems. Health Phys Jul;61(1):15-28. Division of Biomedical Sciences, Univ of California, Riverside 92521. Vertebrates have a number of internal processes for signaling and communication between cell types. Hormones and neurotransmitters move from one cell type to another and carry chemical "messages" that modulate the metabolic responses of tissues to the environment. Interaction with these signaling systems is a potential mechanism by which very low-energy EMFs might produce metabolic responses in the body. Hormone and neurotransmitter receptors are specialized protein molecules that use a variety of biochemical activities to pass chemical signals from the outside of a cell across the plasma membrane to the interior of the cell. Since many low-energy EMFs have too little energy to directly traverse the membrane, it is possible that they may modify the existing signal transduction processes in cell membranes, thus producing both transduction and biochemical amplification of the effects of the field itself. The physiological effects of low-energy EMFs is well established in the healing of bone fractures. The process of regulation of bone turnover and healing is reviewed in the context of clinical applications of EM energy to the healing process, especially for persistent non-union fractures. A hypothetical molecular mechanism is presented that might account for the effects of EMFs on bone cell metabolism in terms of the fields' interference with signal transduction events involved in the hormonal regulation of osteoblast function and differentiation. Publication Types: Review Review, tutorial PMID: 2061045, UI: 91285850

Lunt MJ (1985) Theoretical model for investigating the magnetic and electric fields produced during pulsed magnetic field therapy for non-union of the tibia. Med Biol Eng Comput Jul;23(4):293-300. PMID: 4046650, UI: 86013054

Lunt MJ (1982) Magnetic and electric fields produced during pulsed-magnetic-field therapy for non-union of the tibia. Med Biol Eng Comput Jul;20(4):501-511. PMID: 7132457, UI: 83035509

Madronero A, Pitillas I, Manso FJ (1988) Pulsed EMF treatment failure in radius non-united fracture healing. J Biomed Eng Oct;10(5):463-466. CENIM, Madrid, Spain. PEMF treatment is a non-invasive technique which has wide use in promoting healing of delayed union and non-union of bone. According to reports in the literature, PEMF has a 'success' of about 70%, but with no clear-cut reason to explain the failures. Our tests were carried out on 11 patients with radius non-unions and delayed unions. PEMF failure is associated with implanted metallic plates. In our view, this can be explained because the conducting plates create a uniform bone biopotential around the fracture and thus prevent the negative polarization which stimulates callus formation. Although further controlled and randomized clinical tests are needed, our data show that removal of the plates may be needed before PEMF application. PMID: 3266277, UI: 89179988

Mammi GI, Rocchi R, Cadossi R, Massari L, Traina GC (1993) The electrical stimulation of tibial osteotomies: Double-blind study. Clin Orthop Mar;288:246-253. Dept of Orthopaedics and Traumatology, Ospedale Civile C. Magati, Scandiano (RE), Italy. The effect of EMF stimulation was investigated in a group of 40 consecutive patients treated with valgus tibial osteotomy for degenerative arthrosis of the knee. All patients were operated on by the same author and followed the same postoperative program. After surgery, patients were randomly assigned to a control group (dummy stimulators) or to a stimulated one (active stimulators). 4 orthopedic surgeons, unaware of the experimental conditions, were asked to evaluate the roentgenograms taken 60 d postoperatively and to rate the osteotomy healing according to 4 categories (the 4th category being the most advanced stage of healing). In the control group, 73.6% of the patients were included in the first and second category. In the stimulated group, 72.2% of the patients were included in the third and fourth category. On a homogeneous group of patients, EMF stimulation had positive effects on the healing of tibial osteotomies. Publication Types: Clinical trial Randomized controlled trial PMID: 8458140, UI: 93208951

McLeod KJ, Rubin CT (1992) The effect of low-frequency electrical fields on osteogenesis. J Bone Joint Surg Am Jul;74(6):920-929. Dept of Orthopaedics, School of Med, State Univ of New York, Stony Brook 11794-8181. 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 (15, 75 and 150-Hz) sinusoidal electrical fields. The left ulnae of 30 adult male turkeys were functionally isolated by creation of distal and proximal epiphyseal osteotomies and then were exposed, for 1 h/d, to an electrical field that had been induced exogenously by means of magnetic induction. After a 56-d 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% mean loss of osseous tissue, which was not significantly different than the 10% loss that was caused by disuse treated with inactive coils. Exposure to the pulsed electrical fields prevented this osteopenia and stimulated a 10% mean increase in the bone area. The osteogenic influence of the sinusoidal electrical fields was strongly dependent on the frequency; the 150, 75, and 15-Hz sinusoidal fields, respectively, generated a -3%, + 5%, and + 20% 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. [Published erratum appears in J Bone Joint Surg Am 1992 Sep;74(8):1274]. PMID: 1634583, UI: 92340610

Miller GJ, Burchardt H, Enneking WF, Tylkowski CM (1984) Electromagnetic stimulation of canine bone grafts. J Bone Joint Surg [Am] Jun;66(5):693-698. We evaluated the effect of PEMF stimulation on the rate of healing or incorporation of segmental autogenous cortical bone grafts in the dog in vivo. This non-invasive method of electrical stimulation has been implicated in increasing bone osteogenesis or augmentation of the repair process in the canine fibular osteotomy. We used 2-mo and 6-mo stimulation protocols. At 6 mo, all of the animals were evaluated biomechanically using rapid-loading torsional testing. Histological evaluation using tetracycline labeling was used to evaluate cumulative new-bone formation and porosity, while graft-host time to union was evaluated roentgenographically every 2 wk. Recent reports have implied that particular pulse configurations might be effective in improving graft revascularization and incorporation. Using the particular waveform described, PEMF stimulation had no significant effect on the biomechanical strength, histological presentation, or time to union with either 2 or 6 mo. PMID: 6373772, UI: 84212628

Mishima S (1988) The effect of long-term pulsing EMF stimulation on experimental osteoporosis of rats. Sangyo Ika Daigaku Zasshi Mar 1;10(1):31-45. Dept of Orthopedic Surgery, School of Med, Univ of Occupational and Environmental Health, Kitakyushu, Japan. The author performed experiments in order to investigate what biological effect on the bone would be produced by long-term PEMF systemic stimulation. In some of the mature female rats used as experimental animals, bilateral ovariectomy and right sciatic neurectomy were performed in order to make a model osteoporosis. PEMF stimulation was produced by repetitive pulse burst (RPB) waves at a positive amplitude of 25 mV, negative amplitude of 62.5 mV, burst width of 4.2 ms, pulse width of 230 us and 12 Hz, with the magnetic field strength within a cage being set at 3-10 Gauss. PEMF stimulation over 6 mo did not produce any effects on the physiologically aged bones. PEMF stimulation also did not produce any effects on losed cortical bone in osteoporotic hindlegs. On the other hand, an increase of bone volume and bone formation activity was seen in the cancellous bone of osteoporotic hindlegs. PEMF stimulation had a preventive effect against bone loss of osteoporotic hindlegs. Also, an increase in bone marrow blood flow seemed to be related with this increase of bone volume and bone formation activity. Publication Types: Review Review, tutorial PMID: 3285429, UI: 88218466

Muhsin AU, Islam KM, Ahmed AM, Islam MS, Rabbani KS, Rahman SM, Ahmed S, Hossain M (1991) Effect of pulsed EMF on healing of experimental non-union in rat tibiae. Bangladesh Med Res Counc Bull Jun;17(1):1-10. IPGMR, Dhaka Univ. To see the effect of PEMF on nonunited fracture healing, non-union was induced in rat tibiae and PEMF was applied on it. Of 5 different techniques used to induce non-union, soft tissue interposition was found to be the most suitable and effective method of experimental induction of non-union. 28 experimental and 15 control rats were finally evaluated for the effect of PEMF applied for up to 8 wk. After sacrifice of 8 experimental and 4 controls, 6 experimental and 3 controls, again 6 experimental and 3 controls and finally 8 experimental and 5 controls at 2, 4, 6 and 8 wk respectively of PEMF application no significant difference as to the quality of healing was seen between the experimental and control animals. PEMF seemed to have no beneficial effect on the healing of nonunited fractures in this experiment. PMID: 1953591, UI: 92061882

Nahoda J, Koudela K, Freyova J (1984) [Healing pseudarthroses of the long bones using a pulsating EMF - Article in Czech]. Acta Chir Orthop Traumatol Cech Apr;51(2):138-144. PMID: 6720212, UI: 84198909

O'Connor BT (1984) Pulsed magnetic field therapy for tibial non-union. Lancet Jul 21;2(8395):171-172. Publication Types: Letter PMID: 6146073, UI: 84244912

Ottani V, De Pasquale V, Govoni P, Castellani PP, Ripani M, Gaudio E, Morocutti M (1991) Augmentation of bone repair by pulsed ELF magnetic fields in rats. Anat Anz 172(2):143-147. Istituto di Anatomia Umana Normale, Bologna, Italy. Tibial osteotomies in rats were exposed for 2, 3, 5 and 8 wk to a pulsed extremely low frequency magnetic field. The shape of the pulse was a double halfwave (50 Hz, 70 G). The rate of bone healing was evaluated by light and electron microscopy. An increase of bone healing was found in rats treated with magnetic fields persisting throughout the tested time. The accelerated healing process produced a sequence of morphological appearances identical to those of a normal fracture callus being the enhancement of osteogenesis produced by an acceleration of preliminary ossification. PMID: 2048744, UI: 91264243

Pienkowski D, Pollack SR, Brighton CT, Griffith NJ (1994) Low-power electromagnetic stimulation of osteotomized rabbit fibulae: A randomized, blinded study. J Bone Joint Surg Am Apr;76(4):489-501. Univ of Pennsylvania, Philadelphia 19104. The purpose of this study was to determine whether low-power-consuming symmetrical-waveform EM stimuli could increase the stiffness of fracture sites in a rabbit fibular-osteotomy model. Both active and placebo devices were used in a blinded study protocol. Dose-response studies of pulse amplitude and pulse width were performed by continuous application (24 h/d) of repetitive (15-Hz), bursted (5 ms) symmetrical, rectangular EM stimulus waveforms. The power consumed by these stimuli is approximately 20% of that consumed by the PEMF devices that are in current clinical use. Significant increase of callus bending stiffness was produced by pulse widths of 5-7 us and pulse amplitudes of 50-100 mV. Publication Types: Clinical trial Randomized controlled trial PMID: 8150816, UI: 94201209

Pienkowski D, Pollack SR, Brighton CT, Griffith NJ (1992) Comparison of asymmetrical and symmetrical pulse waveforms in electromagnetic stimulation. J Orthop Res Mar;10(2):247-255. Dept of Orthopaedic Surgery Research, School of Med, Univ of Pennsylvania, Philadelphia 19104. PEMF stimulation is a noninvasive therapeutic modality that has been successfully used to stimulate healing of surgically resistant human bone fracture non-unions. Asymmetry of the stimulus pulse waveform was thought to be necessary for therapeutic effectiveness, but asymmetrical pulses require significant electrical energy that constrains clinical delivery systems to suboptimal designs. Development of low-energy consuming stimuli will enable clinical device improvements and may provide additional information about the interaction of EMFs with tissues. The objectives of this study were (a) to determine if asymmetry of the stimulus pulse waveform is needed for efficacy and (b) to determine if symmetrical pulse waveform stimuli also can produce a beneficial therapeutic response. The rabbit fibular osteotomy model was used to answer these questions and to identify which components of the clinically used asymmetrical PEMF produce the therapeutic response. Asymmetry was not necessary and a narrow pulse width, symmetrical square wave signal also stimulated stiffness increases in this model. The high-amplitude, narrow-pulse portion of the asymmetrical PEMF was the principal component of the signal pulse that induced the clinical therapeutic effect. PMID: 1740743, UI: 92156968

Reddy GN, Saha S (1983) A variable pulse-burst electromagnetic generator for electrical stimulation of biological systems. J Biomed Eng Oct;5(4):336-339. A variable frequency-burst type, EM pulse generator has been developed to optimize the effect of electrical stimulation on bone growth. Using a pair of coils, with 100 turns and 18-gauge wire, the instrument can generate a maximum magnetic field of 300 Gauss. Its pulse repetition frequency can be varied from 10 Hz to 2 KHz and the duty cycle, consisting of several short carrier frequency pulses, can be varied up to 95%. This design also permits the period of the carrier pulse to be changed. PMID: 6632846, UI: 84037881

Reeder MT, Dick BH, Atkins JK, Pribis AB, Martinez JM (1996) Stress fractures: Current concepts of diagnosis and treatment. Sports Med Sep;22(3):198-212. Dept of Family Practice, Albany Med College, New York, USA. Stress fractures are common injuries seen in sports medicine. They occur in many areas of the skeletal system and in multiple sports. However, they are most commonly seen in the lower extremities, with running the reported cause in most cases. Stress fractures result from repetitive, cyclic loading of bone which overwhelms the reparative ability of the skeletal system. Mechanically, three events may lead to stress fractures. First, the applied load can be increased. Secondly, the number of applied stresses can increase. Finally, the surface area over which the load is applied can be decreased. Diagnosis requires thorough clinical evaluation with a high index of suspicion for stress fractures. History must focus on examining the athletes training regimen, especially any changes in distance, running surface and type of shoe. Physical examination varies depending on the location of the stress fracture. Ultrasound is a possible adjunct to the physical examination. Initial plain radiological evaluation may be normal, especially early in the course of a stress fracture. Further radiological evaluation may be necessary to make a definitive diagnosis. Repeating plain radiographs, bone scintigraphy, magnetic resonance imaging and computerised tomography are all possible options. Treatment options begin with rest and cessation of the precipitating activity. This should be 'active rest' in which the athlete continues to exercise depending on the site of the fracture. The athlete should be evaluated from a biomechanical point of view and any abnormalities dealt with before rehabilitation. Possible adjuncts to treatment include pneumatic braces and EMF therapy. There are specific stress fractures that must be considered at-risk for complications of healing. The treatment of these fractures begins with immobilisation and may require surgery pending response to therapy. Stress fractures occur more frequently in female athletes in relation to their male counterparts. The "Female Athlete Triad" (eating disorders, amenorrhea and osteoporosis) is documented. Thus, stress fractures in the female athlete requires additional investigation into those areas. The diagnosis and treatment of stress fractures is a challenge for the physician caring for the athlete. It requires a high index of suspicion combined with a strong knowledge of the at-risk stress fractures and their complications. Accurate and timely diagnosis is required to prevent possible costly and disabling complications. Publication Types: Review Review, tutorial PMID: 8883216, UI: 97037569

Rettig AC, Shelbourne KD, McCarroll JR, Bisesi M, Watts J (1988) The natural history and treatment of delayed union stress fractures of the anterior cortex of the tibia. Am J Sports Med May;16(3):250-255. Thomas A. Brady Sports Med Ctr, Methodist Hospital, Indianapolis, Indiana. This study presents 8 patients with stress fracture of the anterolateral cortex of the midshaft of the tibia. All of the patients, ranging in age from 14-23 yr, were competitive basketball players who experienced pain while running or jumping for an average of 4.4 mo before the diagnosis was made. 8 patients were treated with rest and/or PEMF therapy. Although one of the patients required bone grafting procedure, all 8 of these patients showed complete healing and were able to return to full activity after an average of 8.7 mo of treatment. They have remained asymptomatic for an average of 14.7 mo. The overall time from initial symptoms to return to competition averaged 12.5 mo in this group of athletes. Rest and PEMF therapy may result in healing in some patients with delayed union stress fractures of the anterolateral cortex of the midshaft of the tibia. Although this injury is associated with a prolonged healing period, 7/8 patients with adequate followup in our study were able to return to competition without complications after treatment. One patient was asymptomatic for 33 mo before experiencing a reinjury. Diagnosis of stress fracture should be a primary consideration in basketball players with a prolonged history of pain on the anterolateral aspect of the midthird of the tibia. Once the diagnosis is made we recommend initial treatment consist of rest and external electrical stimulation for a minimum time of 3-6 mo before considering surgical intervention. PMID: 3381982, UI: 88250514

Rubin CT, Donahue HJ, Rubin JE, McLeod KJ (1993) Optimization of electric field parameters for the control of bone remodeling: exploitation of an indigenous mechanism for the prevention of osteopenia. J Bone Miner Res Dec;8 Suppl 2:S573-S581. Dept of Orthopaedics, State Univ of New York, Stony Brook. The discovery of piezoelectric potentials in loaded bone prompted the development of a plausible mechanism by which functional activity could intrinsically influence the tissue's cellular environment and thus affect skeletal mass and morphology. In an in vivo model of osteopenia, we found that exogenous induction of electric fields can prevent or even reverse the bone resorption that normally parallels disuse. Importantly, the manner of the response (formation, turnover, resorption) is exceedingly sensitive to subtle changes in electric field parameters. Fields <10 uV/cm, when induced at frequencies between 50 and 150 Hz for 1 h/d, were enough 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 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. Endogenous electric fields may serve as critical regulators 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, such exogenous treatment may promote bone quantity and quality with minimal risk or consequence. Publication Types: Review Review, tutorial PMID: 8122529, UI: 94168053

Sanders-Shamis M, Bramlage LR, Weisbrode SE, Gabel AA (1989) A preliminary investigation of the effect of selected EMF devices on healing of cannon bone osteotomies in horses. Equine Vet J May;21(3):201-205. Dept of Clinical Sciences, Ohio State Univ, College of Veterinary Med, Columbus 43210. The effect of electrical stimulation by means of selected EMF devices on healing of cannon bone osteotomies in horses was examined. The defects were created as 3 cm x 1 mm longitudinal osteotomies through the dorsal cortices of the mid-metacarpus / metatarsus of adult horses. This type of defect would asses bone healing in a situation similar to an acute, stable fracture of the cortex. Three EM devices of different design were tested in three different groups of horses. Healing was evaluated radiographically and histologically. Osteotomies treated with the EM devices healed similarly to untreated controls. The EM devices studied did not have a local effect on the repair process of an acute, stable, osseous defect. PMID: 2731509, UI: 89276253

Sedel L, Christel P, Duriez J, Duriez R, Evrard J, Ficat C, Cauchoix J, Witvoet J (1981) [Acceleration of repair of non-unions by EMFs - Article in French]. Rev Chir Orthop Reparatrice Appar Mot 67(1):11-23. This work deals with the results obtained by 4 French orthopaedic departments using A. Bassett's method of EMF stimulation for non-union treatment. 37 cases were studied. The results are known for 35, of which 29 were successes and 6 were failures. The failures were explained for 4 of them by a bad application of the device. For the 29 successful cases, the role of the stimulation is discussed. Discarding those who have been treated a short time after a surgical procedure, those who have been immobilized >6 mo and those where the non-union could have been a delayed union, it remains 14 successful cases apparently undisputable. For them the role of the EMF stimulation seems real. PMID: 6453392, UI: 81200370

Sedel L, Christel P, Duriez J, Duriez R, Evrard J, Ficat C, Cauchoix J, Witvoet J (1982) Results of non-unions treatment by pulsed EMF stimulation. Acta Orthop Scand Suppl 196:81-91. PMID: 6950654, UI: 82156081

Simske SJ, Luttges MW (1995) Suspension osteopenia in mice: whole body EMF effects. Bioelectromagnetics 16(3):152-159. Dept of Aerospace Engineering Sciences, Univ of Colorado, Boulder 80309, USA. Whole-body fields were tested for their efficacy in preventing the osteopenia caused by tail suspension in mice. The fields had fundamental frequencies corresponding to the upper range of predicted endogenous impact-generated frequencies (0.25-2.0 kHz) in the long bones. Three distinct whole-body EMFs were applied for 2 wk on growing mice. Structural, geometric, and material properties of the femora, tibiae, and humeri of suspended mice were altered compared to controls. Comparison of suspended mice and mice subjected to caloric restriction shows that the changes in caloric intake do not explain either the suspension or the field-induced effects. In agreement with past studies, rather, unloading seems to cause the suspension effects and to be addressed by the EMFs. The EMF effects on bone properties were apparently frequency dependent, with the lower two fundamental frequencies (260 and 910 Hz) altering, albeit slightly, the suspension-induced bone effects. The fields are not apparently optimized for frequency, etc., with respect to therapeutic potential; however, suspension provides a model system for further study of the in vivo effects of EMFs. PMID: 7677791, UI: 95408313

Sneed NV, VanBree KM (1990) Treating ununited fractures with electricity: nursing implications. J Gerontol Nurs Aug;16(8):26-31. Not only are the elderly more susceptible to fractures because of a decrease in total bone content from osteoporosis, but the regeneration of injured bone may be prolonged as well. When a long bone fracture occurs in the elderly person, weightlessness and immobility result in further acceleration of bone loss. Because the success of PEMF treatments depends on adherence to the treatment protocol, patient education is a key in nursing care. Although all fractures are a serious setback for the elderly person, those that do not heal properly require special considerations and the mobilization of many resources if the patient is to remain out of an institution. PMID: 2387968, UI: 90354615

Steinberg GG (1995) Reversible osteolysis. J Arthroplasty Aug;10(4):556-559. Dept of Orthopedics and Physical Rehabilitation, Univ of Massachusetts Med Ctr, Worcester 01655, USA. This is a case report of a 44-yr-old patient in whom osteolytic changes that developed around the distal end of the femoral prosthesis seemed to reverse with the use of antiinflammatory medication and PEMF stimulation. Most reported cases of osteolysis have been described as showing progressive change at a variable rate. There has not been any previously documented case in which there has been reversal of osteolytic change. PMID: 8523021, UI: 96052061

Synder M (1981) [Radiologic evaluation of bone union of the radius in fresh fractures in rats subjected to magnetic field action - Article in Polish]. Chir Narzadow Ruchu Ortop Pol 46(6):517-521. PMID: 7346241, UI: 82261058

Synder M, Zwierzchowski H, Zielinki KW (1984) [Experimental studies of bone fracture healing in a pulsating magnetic field - Article in German]. Beitr Orthop Traumatol Jan;31(1):1-7. PMID: 6712575, UI: 84178248

Tabrah F, Hoffmeier M, Gilbert F Jr, Batkin S, Bassett CA (1990) Bone density changes in osteoporosis-prone women exposed to pulsed EMFs (PEMFs). J Bone Miner Res May;5(5):437-442. Univ of Hawaii School of Med, Straub Clinic and Hospital, Honolulu. To determine the effect of a 72 Hz PEMF on bone density of the radii of osteoporosis-prone women, the nondominant forearms of 20 subjects were exposed to PEMF 10 h daily for a period of 12 wk. Bone density before, during, and after the exposure period was determined by use of a Norland-Cameron bone mineral analyzer. 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 wk. A similar but weaker response occurred in the opposite arm, suggesting a "cross-talk" effect on the untreated radii, from either possible arm proximity during sleep or very weak general field effects. Properly applied PEMFs, if scaled for whole-body use, may have clinical application in the prevention and treatment of osteoporosis. Publication Types: Clinical trial PMID: 2195843, UI: 90313511

Tager KH (1975) [The use of electrodynamic alternating potential in operative and conservative orthopedics - Article in German]. MMW Munch Med Wochenschr May 9;117(19):791-798. The Kraus-Lechner EMF coil was used in 107 patients for operative (82) and conservative (25) indications. The method was a valuable addition to the therapeutic possibilities so far available for bones and joints. The production of new bone is stimulated; blood flow through the soft parts is promoted and affects the inhibition of inflammation. No extra demands are made on the surgical technique and side effects do not occur. X-ray pictures and the indications listed individually agreed with the results of treatment. PMID: 805945, UI: 75174974

Takano-Yamamoto T, Kawakami M, Sakuda M (1992) Effect of a pulsing EMF on demineralized bone-matrix-induced bone formation in a bony defect in the premaxilla of rats. J Dent Res Dec;71(12):1920-1925. Dept of Orthodontics, Osaka Univ, Faculty of Dentistry, Japan. A 2-mm non-healing bony defect was prepared in the premaxilla of male Wistar rats weighing about 180 g as a simulation of an alveolar cleft, for determination of whether a PEMF could promote regeneration of bone induced by demineralized bone matrix (DBM). The defect was either treated with 7 mg DBM or was left as a non-grafted control. The rats were exposed to a PEMF with a frequency of 100 Hz, a 10-ms-wide burst with 100 us-wide quasi-rectangular pulses, repeating at 15 Hz, and magnetic field strength of 1.5-1.8 G. Alkaline phosphatase activity increased significantly from d 7 in the DBM-graft-plus-PEMF group and from d 10 in the DBM-graft group, reaching a maximum on d 14. A >2-fold rise in alkaline phosphatase activity and a 3-fold rise in the amount of 45Ca incorporation in the DBM-graft-plus-PEMF group were attained compared with those of the DBM-graft group. The DBM-graft-plus-PEMF group produced more bone with almost complete osseous bridging in the defect sites than did the group treated with DBM only on d 35. PEMF seemed to enhance the bone-inductive properties of DBM through the stimulation of osteoblast differentiation induced by DBM. PMID: 1452895, UI: 93085028

Verkerke GJ, Schraffordt Koops H, Veth RP, Grootenboer HJ, De Boer LJ, Oldhoff J, Postma A (1994) Development and test of an extendable endoprosthesis for bone reconstruction in the leg. Int J Artif Organs Mar;17(3):155-162. Ctr for Biomedical Technology, Univ of Groningen, The Netherlands. A malignant bone tumour may develop in the femur of a child. In most cases it is necessary to resect the bone involved, growth plate and adjacent tissues. A modular endoprosthetic system has been developed which can be extended non-invasively to bridge the defect resulting from such a resection. Elongation is achieved by using an external magnetic field. In vitro tests with a prototype showed that the lengthening element met all requirements. 6 animal experiments showed that the lengthening element also functioned in vivo. PMID: 8050807, UI: 94327232

von Satzger G, Herbst E (1981) Surgical and electrical methods in the treatment of congenital and posttraumatic pseudarthrosis of the tibia. Clin Orthop Nov;161:82-104. This is a report of 2 adult patients with posttraumatic and 7 children with congenital pseudarthroses treated by surgical and electrical methods. Interest was focused primarily on congenital pseudarthroses because of the unquestionable severity of these cases and consequently a very high benefit/risk ratio. Three procedures were used: external (Hoffmann) fixation combined with monophasic or biphasic pulsed current stimulation; internal (transtarsal) fixation combined with PEMF stimulation; and surgical treatment only, as above, without electrostimulation. Healing was achieved in both treated cases of posttraumatic pseudarthrosis and in 9/14 instances in cases of congenital pseudarthrosis stimulated electrically, as well as in 2 instances with no electrostimulation. In 7 instances, the bone remained healed for 9 mo or more, the longest period being almost 5.5 yr. Both pulsed current and PEMF stimulation seem to enhance the process of bone healing. However, comparison between the different stimulation methods cannot be made on the basis of the limited material presented here, and the need for more basic studies still exists. Concerning the surgical treatment, it seems that transtarsal fixation is a better choice for congenital pseudarthrosis than fixation with an AO-plate, Rush pin or Hoffmann apparatus. PMID: 6975693, UI: 82071047

Wahlstrom O, Knutsson H (1984) A device for generation of EMFs of extremely low frequency. J Biomed Eng Oct;6(4):293-296. A new device to generate EMFs at extra low frequencies, to be used in fracture treatment, is described. The device involves a coil and a battery powered noise-generator. An alternating magnetic field of 4 X 10(-4) T (4 Gauss) (RMS value) with a frequency range 1-1000 Hz is generated. A controlled randomized study of fresh fractures showed significant differences (p<.01) between the treated group and the control group. The results are encouraging and motivate further investigations with this method. Publication Types: Clinical trial Randomized controlled trial PMID: 6503256, UI: 85059331

Wahlstrom O (1984) Stimulation of fracture healing with EMFs of extremely low frequency (EMF of ELF). Clin Orthop Jun;186:293-301. This randomized, controlled study was performed to evaluate how EMFs affect the accumulation of 99mTechnetium - methylendiphosphonate (Tc-MDP) in fresh fractures. 30 women with Colles' fractures, aged 50-70 yr, participated in this study: some in a control group and some in a treated group. After reduction, all patients were immobilized for 4 wk. After randomization, 15 patients were treated by EMFs of extremely low frequency (EMF of ELF), which were generated by a coil and a battery-powered portable current generator during the time of immobilization. The frequency of the alternating magnetic field was 1-1000 Hz; the magnitude was 4 Gauss [RMS (root-mean-square) value]. The scintigrams were performed 1, 2, 4, and 8 wk after the injury. The activity ratio in the fracture area was significantly higher at the examination of 1 and 2 wk (p<.05, p<.01) in the treated group than it was in the control group. The clinical relevance of the results is not known, but one interpretation of the data is that the stimulation with EMF of ELF improves (accelerates) the early phase of fracture healing. The data warrant further investigation of fresh fracture treatment with this method. PMID: 6233054, UI: 84206316

Walenczak K, Widawski T (1993) [A case of stress fracture of the femoral neck - Article in Polish]. Chir Narzadow Ruchu Ortop Pol 58(6):471-473. oddzialu Urazowo-Ortopedycznego Szpitala MSW W Lodzi. A case of 28 yr old male with stress fracture of the femoral neck is presented. Heterogeneous clinical picture is blamed for diagnostic problems in the initial stage of the disease. Bone scintigraphy aids in the early diagnosis. The use of low frequency EMF definitely shortened the treatment time in the case reported. PMID: 7555308, UI: 96012786

Wiendl HJ, Strigl M (1978) [Clinical experiences in supplementary treatment of pseudarthroses using electromagnetic potentials - Article in German]. Fortschr Med Feb 2;96(5):231-236. Kraus-Lechner electromagnetic alternating field therapy was performed postoperatively in addition to osteosynthesis in 22 cases of pseudarthrosis after fractures of the limbs, 5 osteotomies and one fresh fracture of the lower leg. Except for one failure, all cases showed a complete and clearly accelerated osseous bridging. This method gave added success especially in preoperated and problem-cases such as pseudarthrosis of the femoral neck and defect-pseudarthrosis with tibial inflammation. PMID: 304436, UI: 78085891

1b. Joint problems, fractures, arthritis

Galkina MG, Shargorodskaia DV, Roshchina NA (1987) [Reflexotherapy of osteoarthritis patients using the action of a UHF EMF - Article in Russian]. Revmatologiia (Mosk) Jul;3:40-44. PMID: 3317712, UI: 88070073

Glazer PA, Heilmann MR, Lotz JC, Bradford DS (1997) Use of EMFs in a spinal fusion: A rabbit model. Spine Oct 15;22(20):2351-2356. Dept of Orthopaedic Surgery, Univ of California, San Francisco, USA. To evaluate the influence of a PEMF on the spinal fusion rate and biomechanical characteristics in a rabbit model, a prospective, randomized trial analyzed the biomechanical and histologic features of posterolateral spinal fusion in rabbits with and without the application of a PEMF. Also, biomechanical testing, radiographs, and manual palpation assessed the fusion rate with and without a PEMF. Previous studies to assess the benefits of a PEMF in spinal fusion were complicated by the use of instrumentation, and the animal models used do not have a pseudarthrosis rate comparable to that in humans. In contrast, the use of instrumentation does not complicate posterolateral intertransverse process fusion in rabbits, which have a pseudarthrosis rate similar to that in humans (5-35%). 10 New Zealand white rabbits each were randomly assigned to undergo spinal fusion using either 1) autologous bone with EMFs, or 2) autologous bone without EMFs. A specially designed plastic constraint was used to focus the PEMF for 4 h/d over the rabbits' lumbar spine. Animals were killed at 6 wk for biomechanical and histologic testing. As evaluated by radiograph and manual examination in a blinded fashion, PEMF decreased pseudarthrosis rate from 40 to 20%. However, as there were only 5 animals/group, the decrease in non-union rate was not statistically significant. Biomechanical analysis of the fusion mass showed that a PEMF resulted in statistically significant increases in stiffness (35%), area under the load-displacement curve (37%), and load to failure of the fusion mass (42%). Qualitative histologic assessment showed increased bone formation in those fusions exposed to a PEMF. This rabbit fusion model was reproducable, and a PEMF induced a statistically significant increase in stiffness, area under the load-displacement curve, and load to failure of the fusion mass. This is a basis for continued evaluation of biologic enhancement of spinal arthrodesis with the use of a PEMF. Publication Types: Clinical trial Randomized controlled trial PMID: 9355215, UI: 98016835

Godley DR (1997) Nonunited carpal scaphoid fracture in a child: treatment with pulsed EMF stimulation. Orthopedics Aug;20(8):718-719. Dept of Orthopedic Surgery, Permanente Med Group Inc, San Jose, Calif. 95119, USA. PMID: 9263293, UI: 97408774

Grabski RS, Czopek A, Grabski SJ (1988) [Treatment of selected injuries of the knee joint by a high-frequency impulse magnetic field - Article in Polish]. Chir Narzadow Ruchu Ortop Pol 53(1):18-22. PMID: 3409766, UI: 88311988

Grace KL, Revell WJ, Brookes M (1998) The effects of pulsed electromagnetism on fresh fracture healing: osteochondral repair in the rat femoral groove. Orthopedics Mar;21(3):297-302. Dept of Orthopedics, UMDS Guy's Hospital, Rayne Institute, London, UK. Some clinical studies have claimed significant reductions in the healing time of fresh fractures with the use of PEMFs. Animal models, however, have produced more equivocal results. This investigation examined the effects of PEMF treatment on an osteochondral defect placed in the patellofemoral groove of the rat. PEMF enhanced early vascular reaction and suppresses initial pannus proliferation. Early chondrogenesis and bone formation were consistently stimulated, and the restoration of normal bone trabeculae advanced. PEMF treatment therefore may be useful in advancing repair during the early proliferative stage. Later results were variable and suggest that prolonged use may have deleterious effects, enhancing chondrogenesis beyond a point seen in normal repair and thus delaying normal subsurface trabeculation. PMID: 9547814, UI: 98209034

Guizzardi S, Di Silvestre M, Govoni P, Scandroglio R (1994) Pulsed EMF stimulation on posterior spinal fusions: a histological study in rats. J Spinal Disord Feb;7(1):36-40. Institute of Histology and Embryology, Univ of Parma, Italy. This study reports the histological data relative to the effect of PEMFs on the evolution of posterior arthrodesis induced in the lumbar vertebrae of 12 adult male Sprague-Dawley rats. After the operation, one group of 6 rats was stimulated with PEMFs for 18 h/d, by means of a pair of coils fixed to the outside of the cage. A control group of 6 rats was given no stimulation after surgery. Acceleration of the process of bone callus organization was already seen after 4 wk, and even more so after 8 wk in the PEMF-stimulated groups. An early replacement of the newly formed cartilage tissue with primary bone (at 4 wk) and subsequently with secondary bone (after 8 wk) was seen. PMID: 8186587, UI: 94243165

Khabirova GF (1978) [Use of magnetic field for the treatment of intra-articular injuries - Article in Russian]. Ortop Travmatol Protez Dec;12:53-57. PMID: 745848, UI: 79135998

Leclaire R, Bourgouin J (1991) Electromagnetic treatment of shoulder periarthritis: a randomized controlled trial of the efficiency and tolerance of magnetotherapy. Arch Phys Med Rehabil Apr;72(5):284-287. Rehabilitation Med Service, Notre Dame Hospital, Montreal, Quebec, Canada. The potential benefit of magnetotherapy was investigated in 47 consecutive outpatients with periarthritis of the shoulder. Using a controlled triple-blind study design, one group of patients received hot pack applications and passive manual stretching and pulley exercises; the other group received the same therapy plus magnetotherapy. Treatment was given 3 times/wk. For a maximum of 3 mo, a standardized treatment protocol was used. There was no significant improvement in pain reduction or in range of motion with EMF therapy. After 12 wk of therapy, the patients who received magnetotherapy showed mean pain scores of 1.5 (+.61 SD) at rest, 2.2 (+.76 SD) on movement, and 1.9 (+.94 SD), on lying, compared to scores for the control group of 1.4 (+.65 SD), 2.2 (+.7 SD), and 1.9 (+.95 SD), respectively. Linear pain scale scores improved from 71 to 21 for both groups. At 12 wk the gain in range of motion was mean 109+46.8o in patients receiving EMF therapy, compared to 122+33.4o for the controls (not significant). At entry, the functional handicap score was 53.5 for both groups. At 12 wk, it was 24 for the magnetotherapy group and 17 for the control group (difference not significant). This study showed no benefit from magnetotherapy in the pain score, range of motion, or improvement of functional status in patients with periarthritis of the shoulder. Publication Types: Clinical trial Randomized controlled trial PMID: 2009043, UI: 91181967

Lluch BC, Garcia-Andrade DG, Munoz FL, Stern LL (1996) [Usefulness of EMFs in the treatment of hip avascular necrosis: a prospective study of 30 cases - Article in Spanish]. Rev Clin Esp Feb;196(2):67-74. Servicio de Cirugia Ortopedica y Traumatologia, Hospital Universitario San Carlos, Madrid. A series is here reported of 30 hips from 21 patients with the diagnosis of avascular necrosis in different stages (Ficat 0=1, I=4, II=13, III=10, IV=2). Patients underwent external electro-stimulation by means of a EMF generator, and results were evaluated by NMR at 3-mo intervals. Lesions were categorized by NMR: < 25%, 25%-50%, and > 50% of involved head volume. The grading of lesions yielded the following distribution: grade 1=12, grade 2=10, and grade 3=7. Results were categorized in "clinical success", "NMR success" and "combined success" when symptoms decreased or disappeared, the lesion stabilized by NMR, or both, respectively. Overall, the corresponding figures were 80%, 76.6%, and 63.3%, and were remarkably influenced by the NMR grading of the lesion. PMID: 8685491, UI: 96286249

Mitbreit IM, Savchenko AG, Volkova LP, Proskurova GI, Shubina AV (1986) [Low-frequency magnetic field in the complex treatment of patients with lumbar osteochondrosis - Article in Russian]. Ortop Travmatol Protez Oct;10:24-27. PMID: 3808656, UI: 87117093

Mohamed-Ali H, Kolkenbrock H, Ulbrich N, Sorensen H, Kramer KD, Merker HJ (1994) Influence of EMFs on the enzyme activity of rheumatoid synovial fluid cells in vitro. Eur J Clin Chem Clin Biochem Apr;32(4):319-326. Institut fur Anatomie, Freie Universitat Berlin, Germany. Since positive clinical effects have been seen in the treatment of rheumatoid arthritis with EMFs of weak strength and low frequency range (magnetic field strength: 70 uT; frequency: 1.36-14.44 Hz), an attempt was made to analyse the effects of these EMFs on enzyme activity in monolayer cultures of rheumatoid synovial fluid cells after single irradiation of the cultures for 24 h. We only studied the matrix metalloproteinases (collagenase, gelatinase, proteinase 24.11 and aminopeptidases). It was found that EMFs of such a weak strength and low frequency range do not generally have a uniform effect on the activity of the different proteinases in vitro. While aminopeptidases do not show any great changes in activity, the peptidases hydrolysing N(2,4)-dinitrophenyl-peptide exhibit a distinct increase in activity in the late phase in culture medium without fetal calf serum. This effect was not seen in the presence of fetal calf serum, and enzyme activity fell. Our experiments do not show whether such a phase-bound increase in the activity of proteinases in vitro is only one finding in a much broader range of effects of EMFs, or whether it is a specific effect of weak pulsed magnetic fields of 285+33 nT on enzyme activity after single irradiation. This question requires further elucidation. PMID: 8038273, UI: 94312509

Mooney V (1990) A randomized double-blind prospective study of the efficacy of pulsed EMFs for interbody lumbar fusions. Spine Jul;15(7):708-712. Division of Orthopaedic Surgery, Univ of California, Irvine. A randomized double-blind prospective study of PEMFs for lumbar interbody fusions was performed on 195 subjects. There were 98 subjects in the active group and 97 subjects in the placebo group. A brace containing equipment to induce an EMF was applied to patients undergoing interbody fusion in the active group, and a sham brace was used in the control group. In the active group there was a 92% success rate, while the control group had a 65% success rate (p>.005). The data showed the effectiveness of bone graft stimulation with the device. Publication Types: Clinical trial. Randomized controlled trial PMID: 2218718, UI: 91019677

Ponomarev VD, Bogoliubov VM, Frenkel' ID, Pershin SB, Ponomarev IuT (1986) [Characteristics of the course of experimental arthritis after bitemporal exposure to an ultrahigh-frequency electric field - Article in Russian]. Patol Fiziol Eksp Ter Sep;5:74-77. PMID: 3797098, UI: 87091298

Reut NI (1990) [Manual and magneto-barotherapy of spinal osteochondrosis - Article in Russian]. Ortop Travmatol Protez Aug;8:29-31. The problem of the spinal osteochondrosis treatment has not been solved yet. Commonly applicable manual therapy is not always effective. In order to liquidate complex degenerative hypoxic processes in soft tissues of spine, cervical, thoracal and lumbar parts of spine of 468 patients aged from 20-80 yr, in line with the manual therapy, have been exposed to hyperbaric oxygenation with constant magnetic field. In case of persistent pathologic process in spine a single kenalog-novocaine blockade after Shneck was additionally applied. Prolonged good and excellent results were achieved with all patients during 3 yr. Mean term of invalidity was 7 d. Proposed method of spinal osteochondrosis treatment in polyclinic facilitates the economic situation of hospitals and saves patients from hospital bed. PMID: 2074955, UI: 91163939

Serbiuk VV (1978) [Magnetic field in the complex therapy of the knee joint injuries complicated by purulent infection - Article in Russian]. Ortop Travmatol Protez Nov;11:44-47. PMID: 733209, UI: 79094877