Electromagnetic fields and magnets. Investigational treatment for musculoskeletal disorders

Osteocyte: the impresario in the electrical stimulation for bone fracture healing

Delayed healing and nonunions of bone fracture are critical problems in orthopedic surgery. Electrical stimulation has been used as a therapeutic method for enhancing bone healing for a long time. Despite unanimous clinical success, the underlying mechanism concerning bone tissue in response to electrical stimulation remains poorly understood. In the meantime, emerging evidences suggest that osteocytes, with their unique location and morphologies, play an important role in regulating the behaviors of other bone cells, including osteoblasts, osteoclasts and their progenitor cells. In this paper, we hypothesize that osteocytes are the sensory cells for the electrical stimulation, and they orchestrate the whole process of new bone formation and remodeling in the electrotherapy for bone fracture. The postulated electrosensory transduction pathway might be a coupling effect of osteoblasts and osteoclasts, which is regulated by the biochemical signals expressed from osteocytes after sensing the membrane potential changes. It is believed that better understanding of this mechanism would facilitate optimizing the electrotherapy for bone disorders and assist in solving these clinical problems.

Effect of pulsed magnetic field therapy on pain reported by human volunteers in a laboratory model of acute pain †

BACKGROUND

Pulsed magnetic field therapy (PMFT) is a non-invasive, simple technique used extensively for the treatment of muscle pain. However, evidence to support its use from well-designed, clinical, or experimental studies is sparse.

METHODS

We have utilized an acute pain model to perform a randomized, double-blinded, placebo-controlled, crossover-study on 10 male (18-40 yr) volunteers. Pain was elicited by infusion of hypertonic saline 5% into the brachioradialis muscle of the non-dominant arm on two occasions, at least 1 week apart. Subjects received active or sham PMFT for 30 min in a randomized order delivered by two identical, commercially available machines (PulsePack 6000, Quantum Techniks). The active machine delivered a M-wave magnetic pulse (1.25 Hz, 3 ms width, 600 Gauss); the sham device was deactivated and delivered no magnetic energy. Pain was assessed at 15-s intervals, and area under the visual analogue score (VAS) pain curve (AUCp) was calculated using the trapezoid method.

RESULTS

There were no significant differences in mean VAS pain scores between the two machines at any time. In addition, there were no significant differences with respect to mean (sem) maximum pain score [sham 60 (8), active 63 (9) mm; P = 0.66, 95% CI -18 to 12 mm] or AUCp [sham 463 (50), active 499 (90); P = 0.64, 95% CI -201 to 129].

CONCLUSIONS

We conclude that, using the electromagnetic characteristics of the machine in this study, the PMFT had no effect on pain in our experimental model. More work is required to provide an evidence base in support of the use of this technique for pain.

Racial/Ethnic Differences in the Use of Complementary and Alternative Medicine in Patients With Arthritis

OBJECTIVE

To examine use of complementary and alternative medicine (CAM) by individuals with osteoarthritis (OA) from 4 ethnic groups, differences in CAM use among groups, and correlates of CAM use.

METHODS

Data were obtained from individuals from 4 ethnic groups (African, Asian, and Hispanic Americans, and Caucasians) participating in trials assessing celecoxib efficacy. A questionnaire assessing CAMs specifically used to help arthritis was administered at screening. Use of 42 specific therapies within 7 categories-alternative medical systems, mind-body interventions, manipulation and body-based methods, energy therapies, and 3 types of biologically based therapies--was queried.

RESULTS

More than 80% of subjects reported that they used some CAM for arthritis in the past month. In contrast, 50% reported the use of prescription medicines, and 52% reported the use of over-the-counter medicines. Dietary practices were the most common type of CAM (71.5%), followed by mind-body interventions (42.4%), topical agents (38.1%), use of supplements or herbs (32.9%), and manipulation and body-based methods (21.4%). African Americans were more likely to report any CAM use than other groups (89.1% versus 83.1% [Asian], 81.1% [Hispanic], 77.7% [Caucasian]). African and Asian Americans more commonly reported the use of mind-body interventions in general, and prayer in particular. African Americans were also most likely to report the use of topical agents. Asian Americans were most likely to report use of alternative medical systems, manipulation methods, and supplements. Caucasians were least likely to report use of dietary practices.

CONCLUSION

Individuals with OA commonly use CAM. Use of these therapies varies by racial/ethnic group. Some CAMs may be effective for symptom relief, while others may interact with prescription medications, suggesting that routine queries by physicians concerning CAM use would be beneficial.

Static magnetic fields up-regulate osteoblast maturity by affecting local differentiation factors

Cell culture studies have shown that static magnetic fields induce osteoblastic differentiation at an early stage. However, the mechanisms of differentiated effects have not been well described. We postulated that static magnetic fields stimulate osteoblastic differentiation by regulating early local factors released by the cells. To examine our hypothesis, MG63 osteoblast-like cells were exposed continuously to 0.4-T static magnetic fields for 12, 24, 48, and 72 hours. The morphologic changes and matrix vesicles release were observed by scanning and transmission electron microscopy. The effects of static magnetic fields on levels of transforming growth factor-beta1, Type I collagen, osteopontin, and alkaline phosphatase were compared between the exposed and unexposed cells. The data suggest MG63 cells treated with static magnetic fields have more differentiated morphologic features. The local regulatory factors produced by static magnetic field-treated cells were greater than those of the control cultures. These findings provide evidence that static magnetic fields affect osteoblastic maturation by up-regulating early local factors.

Effectiveness of pulsed electromagnetic field therapy in lateral epicondylitis

We aimed to investigate the efficacy of pulsed electromagnetic field (PEMF) in lateral epicondylitis comparing the modality with sham PEMF and local steroid injection. Sixty patients with lateral epicondylitis were randomly and equally distributed into three groups as follows: Group I received PEMF, Group II sham PEMF, and Group III a corticosteroid + anesthetic agent injection. Pain levels during rest, activity, nighttime, resisted wrist dorsiflexion, and forearm supination were investigated with visual analog scale (VAS). Pain threshold on elbow was determined with algometer. All patients were evaluated before treatment at the third week and the third month. VAS values during activity and pain levels during resisted wrist dorsiflexion were significantly lower in Group III than Group I at the third week. Group I patients had lower pain during rest, activity and nighttime than Group III at third month. PEMF seems to reduce lateral epicondylitis pain better than sham PEMF. Corticosteroid and anesthetic agent injections can be used in patients for rapid return to activities.

Low-intensity pulsed ultrasound for bone healing: an overview

Low-intensity ultrasound is a biophysical form of intervention in the fracture-repair process, which through several mechanisms accelerates healing of fresh fractures and enhances callus formation in delayed unions and nonunions. The goal of this review is to present the current knowledge obtained from basic science and animal studies, as well as existing evidence from clinical trials and case series with the different applications of ultrasound in the management of fractures, delayed unions, nonunions and distraction osteogenesis. Low-intensity pulsed ultrasound is currently applied transcutaneously, although recent experimental studies have proven the efficacy of a trans-osseous application for both enhancement and monitoring of the bone healing process with modern smart implant technologies.

Interference of programmed electromagnetic stimulation with pacemakers and automatic implantable cardioverter defibrillators

A commercially available magnetic therapy system, designed for clinical application as well as for private use without medical supervision, was examined with respect to its potential for causing electromagnetic interference with implantable pacemakers (PMs) and automatic implantable cardioverter defibrillators (AICDs). A sample of 15 PMs and 5 AICDs were experimentally investigated. Each of the implants was realistically positioned in a homogeneous, electrically passive torso phantom and exposed to the magnetic fields of the system's applicators (whole body mat, cushion, and bar applicator). The detection thresholds of the implants were programmed to maximum sensitivity and both unipolar as well as bipolar electrode configurations were considered. The evaluation of possible interferences was derived from the internal event storages and pacing statistics recorded by the implants during exposure. Any "heart activity" recorded by the implants during exposure was interpreted as a potential interference, because the implant obviously misinterpreted the external interference signal as a physiological signal. Only cases without any recorded "heart activity" and with nominal pacing rates (as expected from the program parameter settings) of the implants were rated as "interference-free." Exposure to the whole body mat (peak magnetic induction up to 265 microT) did not show an influence on PMs and AICD in any case. The cushion applicator at the highest field intensity (peak magnetic induction up to 360 microT) led to atrial sensing defects in four PM models with unipolar electrode configuration. Under bipolar electrode configuration no disturbances occurred. The bar applicator led to sensing problems and consecutively reduced pacing rates in all tested PM models under unipolar electrode configuration and maximum field intensity (peak magnetic induction up to 980 microT). Bipolar electrode configuration resolved the problem. The investigated AICDs did not show malfunctions under any investigated condition. In conclusion, the examined PEMF therapy system did not interfere with the investigated implantable cardiac devices with bipolar electrode configuration. However, unipolar electrode configuration in pacemakers seems to be potentially hazardous during application of the examined PEMF therapy system.

Ice and pulsed electromagnetic field to reduce pain and swelling after distal radius fractures

OBJECTIVE

To examine the relative effectiveness of ice therapy and/or pulsed electromagnetic field in reducing pain and swelling after the immobilization period following a distal radius fracture.

METHODS

A total of 83 subjects were randomly allocated to receive 30 minutes of either ice plus pulsed electromagnetic field (group A); ice plus sham pulsed electromagnetic field (group B); pulsed electromagnetic field alone (group C), or sham pulsed electromagnetic field treatment for 5 consecutive days (group D). All subjects received a standard home exercise programme. A visual analogue scale was used for recording pain; volumetric displacement for measuring the swelling of the forearm; and a hand-held goniometer for measuring the range of wrist motions before treatment on days 1, 3 and 5.

RESULTS

At day 5, a significantly greater cumulative reduction in the visual analogue scores as well as ulnar deviation range of motion was found in group A than the other 3 groups. For volumetric measurement and pronation, participants in group A performed better than subjects in group D but not those in group B.

CONCLUSION

The addition of pulsed electromagnetic field to ice therapy produces better overall treatment outcomes than ice alone, or pulsed electromagnetic field alone in pain reduction and range of joint motion in ulnar deviation and flexion for a distal radius fracture after an immobilization period of 6 weeks.

Effect of magnetic vs sham-magnetic insoles on nonspecific foot pain in the workplace: a randomized, double-blind, placebo-controlled trial

OBJECTIVE

To determine whether magnetic insoles are effective for relieving nonspecific subjective foot pain in the workplace, resulting in improved job satisfaction.

SUBJECTS AND METHODS

A prospective, randomized, double-blind, placebo-controlled study of health care employees who experienced nonspecific foot pain for at least 30 days, which occurred more days than not, was conducted between February 2001 and January 2002 at the Mayo Clinic in Rochester, Minn. Participants were asked to wear either magnetic or sham-magnetic cushioned insoles for at least 4 hours daily, 4 days per week for 8 weeks. The primary outcome variable was reported foot pain (by categorical response of change from baseline and by visual analog scale) at 4 and 8 weeks. Secondary outcome variables included graded intensity of pain experienced during various daily activities and the effect of insoles on job performance and enjoyment.

RESULTS

Among 89 enrolled participants, 6 either withdrew before wearing insoles or were noncompliant with follow-up questionnaires; 83 participants remained for full statistical analysis. Participants in both treatment groups reported improvements in foot pain during the study period. No significant differences in categorical response to pain or pain intensity were seen with use of magnetic vs sham-magnetic insoles.

CONCLUSIONS

The magnetic insoles used in this study by a heterogeneous population with chronic nonspecific foot pain were not clinically effective. Findings confirmed that nonspecific foot pain significantly interferes with some employees' ability to enjoy their jobs and that treatment of that pain improves job satisfaction.

Pulsed electromagnetic field therapy and osteoarthritis of the knee: Synthesis of the literature

Knee joint osteoarthritis is a painful disorder, often resulting in progressive functional impairment and disability. One modality used in the treatment of knee osteoarthritis is pulsed electromagnetic field therapy. This article examines the evidence base that details the rationale for and the outcomes of applying pulsed electromagnetic fields to the osteoarthritic knee joint.

The related English language literature was reviewed to examine whether pulsed electromagnetic fields applied to an osteoarthritic knee joint are likely to be efficacious, and if so why. Although limitations to the published literature on this topic exist, the available basic and seven randomized clinical research studies in this field support the value of continuing to explore the potential of applying pulsed electromagnetic fields to ameliorate pain and dysfunction associated with the osteoarthritic knee joint.

Further clinical research to validate the use of pulsed electromagnetic fields in lessening osteoarthritic knee joint pain and facilitating function and joint repair is indicated.

Treatment of knee osteoarthritis with pulsed electromagnetic fields: a randomized, double-blind, placebo-controlled study

OBJECTIVE

The investigation aimed at determining the effectiveness of pulsed electromagnetic fields (PEMF) in the treatment of osteoarthritis (OA) of the knee by conducting a randomized, double-blind, placebo-controlled clinical trial.

DESIGN

The trial consisted of 2h daily treatment 5 days per week for 6 weeks in 83 patients with knee OA. Patient evaluations were done at baseline and after 2 and 6 weeks of treatment. A follow-up evaluation was done 6 weeks after treatment. Activities of daily living (ADL), pain and stiffness were evaluated using the Western Ontario and McMaster Universities (WOMAC) questionnaire.

RESULTS

Within group analysis revealed a significant improvement in ADL, stiffness and pain in the PEMF-treated group at all evaluations. In the control group there was no effect on ADL after 2 weeks and a weak significance was seen after 6 and 12 weeks. Significant effects were seen on pain at all evaluations and on stiffness after 6 and 12 weeks. Between group analysis did not reveal significant improvements over time. Analysis of ADL score for the PEMF-treated group revealed a significant correlation between less improvement and increasing age. Analysis of patients <65 years using between group analysis revealed a significant improvement for stiffness on treated knee after 2 weeks, but this effect was not observed for ADL and pain.

CONCLUSIONS

Applying between group analysis we were unable to demonstrate a beneficial symptomatic effect of PEMF in the treatment of knee OA in all patients. However, in patients <65 years of age there is significant and beneficial effect of treatment related to stiffness.

Complementary and Alternative Pain Therapy in the Emergency Department

One primary reason patients go to emergency departments is for pain relief. Understanding the physiologic dynamics of pain, pharmacologic methods for treatment of pain, as well CAM therapies used in treatment of pain is important to all providers in emergency care. Asking patients about self-care and treatments used outside of the emergency department is an important part of the patient history. Complementary and alternative therapies are very popular for painful conditions despite the lack of strong research supporting some of their use. Even though evidenced-based studies that are double blinded and show a high degree of interrater observer reliability do not exist, patients will likely continue to seek out CAM therapies as a means of self-treatment and a way to maintain additional life control. Regardless of absolute validity of a therapy for some patients, it is the bottom line: "it seems to help my pain." Pain management distills down to a very simple endpoint, patient relief, and comfort. Sham or science, if the patient feels better, feels comforted, feels less stressed, and more functional in life and their practices pose no health risk, then supporting their CAM therapy creates a true wholistic partnership in their health care.CAM should be relatively inexpensive and extremely safe. Such is not always the case, as some patients have discovered with the use of botanicals. It becomes an imperative that all providers be aware of CAM therapies and informed about potential interactions and side effects when helping patients manage pain and explore adding CAM strategies for pain relief. The use of regulated breathing, meditation, guided imagery, or a massage for a pain sufferer are simple but potentially beneficial inexpensive aids to care that can be easily employed in the emergency department. Some CAM therapies covered here, while not easily practiced in the emergency department, exist as possibilities for exploration of patients after they leave, and may offer an improved sense of well-being and empowerment in the face of suffering and despair. The foundations of good nutrition, exercise, stress reduction, and reengagement in life can contribute much to restoring the quality of life to a pain patient. Adding nondrug therapies of physical therapy, cognitive-behavioral therapy, TENS, hypnosis, biofeedback, psychoanalysis, and others can complete the conventional picture. Adding in simple mind/body therapies, touch therapies, acupuncture, or others may be appropriate in select cases, and depending on the circumstances, may effect and enhance a conventional pain management program. Armed with an understanding of pain dynamics and treatments, practitioners can better meet patient needs, avoid serious side effects, and improve care when addressing pain management in the emergency department.

Stimulators of bone healing. Biologic and biomechanical

Bone is a dynamic biologic tissue. Metabolically active, the stimuli for bone degeneration and regeneration is influenced and modulated by biomechanical and biologic (cellular, hormonal, and molecular) physiologic processes. This article discusses the biologic and biomechanical stimulators and inhibitors of bone healing.

Efficacy of static magnetic field therapy in chronic pelvic pain: a double-blind pilot study

OBJECTIVE

The aim of the study was to determine the efficacy of static magnetic field therapy for the treatment of chronic pelvic pain (CPP) by measuring changes in pain relief and disability.

STUDY DESIGN

Thirty-two patients with CPP completed 2 weeks and 19 patients completed 4 weeks of randomized double-blind placebo-controlled treatment at a gynecology clinic. Active (500 G) or placebo magnets were applied to abdominal trigger points for 24 hour per day. The McGill Pain Questionnaire, Pain Disability Index, and Clinical Global Impressions Scale were outcome measures.

RESULTS

Patients receiving active magnets who completed 4 weeks of double-blind treatment had significantly lower Pain Disability Index (P <.05), Clinical Global Impressions-Severity (P <.05), and Clinical Global Impressions-Improvement (P <.01) scores than those receiving placebo magnets, but were more likely to correctly identify their treatment (P <.05).

CONCLUSION

SMF therapy significantly improves disability and may reduce pain when active magnets are worn continuously for 4 weeks in patients with CPP, but blinding efficacy is compromised.

Electromagnetic fields for the treatment of osteoarthritis

BACKGROUND

As the focus for osteoarthritis (OA) treatment shifts away from drug therapy, we consider the effectiveness of pulsed electric stimulation which is proven to stimulate cartilage growth on the cellular level.

OBJECTIVES

1)To assess the effectiveness of pulsed electric stimulation for the treatment of osteoarthritis (OA). 2) To assess the most effective and efficient method of applying an electromagnetic field, through pulsed electromagnetic fields (PEMF) or electric stimulation, as well as the consideration of length of treatment, dosage, and the frequency of the applications.

SEARCH STRATEGY

We searched PREMEDLINE, MEDLINE, HealthSTAR, CINAHL, PEDro, and the Cochrane Controlled Trials Register (CCTR) up to and including 2001. This included searches through the coordinating offices of the trials registries of the Cochrane Field of Physical and Related Therapies and the Cochrane Musculoskeletal Group for further published and unpublished articles. The electronic search was complemented by hand searches and experts in the area.

SELECTION CRITERIA

Randomized controlled trials and controlled clinical trials that compared PEMF or direct electric stimulation against placebo in patients with OA.

DATA COLLECTION AND ANALYSIS

Two reviewers determined the studies to be included in the review based on inclusion and exclusion criteria (JH,VR) and extracted the data using pre-developed extraction forms for the Cochrane Musculoskeletal Group. The methodological quality of the trials was assessed by the same reviewers using a validated scale (Jadad 1996). Osteoarthritis outcome measures were extracted from the publications according to OMERACT guidelines (Bellamy 1997) and additional secondary outcomes considered.

MAIN RESULTS

Only three studies with a total of 259 OA patients were included in the review. Electrical stimulation therapy had a small to moderate effect on outcomes for knee OA, all statistically significant with clinical benefit ranging from 13-23% greater with active treatment than with placebo. Only 2 outcomes for cervical OA were significantly different with PEMF treatment and no clinical benefit can be reported with changes of 12% or less.

REVIEWER'S CONCLUSIONS

Current evidence suggests that electrical stimulation therapy may provide significant improvements for knee OA, but further studies are required to confirm whether the statistically significant results shown in these trials confer to important benefits.

Effect of magnetic insoles on postural sway measures in men and women during a static balance test

Numerous anecdotal reports have suggested a growing public enthusiasm for magnetic devices for treatment of pain and various motor and sensory dysfunctions. Although the principles behind magnetic therapy are well documented, a complete technical explanation of whether static magnet application is effective is lacking due to a paucity of scientific research. In this study the effectiveness of magnetic insoles on postural sway measures during a single application were investigated. Twenty-eight adults (14 old, 14 young) were assessed on postural sway measures while performing a static two-legged stance test on a Kistler force platform under two treatment conditions (magnetic insoles, nonmagnetic insoles). Significant reductions in total sway area and lateral sway scores were obtained by the older adults while standing on the magnetic insoles. These preliminary results indicate that treatment of postural instability using magnetic insoles may be a viable alternative for older adults.

Complementary and alternative therapies for fibromyalgia

Fibromyalgia (FM) is a syndrome of chronic widespread musculoskeletal pain that is accompanied by sleep disturbance and fatigue. Clinical treatment usually includes lifestyle modifications and pharmacologic interventions meant to relieve pain, improve sleep quality, and treat mood disorders. These therapies are often ineffective or have been shown in clinical studies to have only short-term effectiveness. Pharmacologic treatments have considerable side effects. Patients may have difficulty complying with exercise-based treatments. Thus, patients seek alternative therapeutic approaches and physicians are routinely asked for advice about these treatments. This article reviews nontraditional treatment alternatives, from use of nutritional and herbal supplements to acupuncture and mind-body therapy. Little is known about efficacy and tolerance of complementary and alternative therapies in FM and other chronic musculoskeletal pain syndromes. Most studies on these treatments have been performed for osteoarthritis, rheumatoid arthritis, or focal musculoskeletal conditions. Clinical trials are scarce; the quality of these trials is often criticized because of small study population size, lack of appropriate control interventions, poor compliance, or short duration of follow-up. However, because of widespread and growing use of alternative medicine, especially by persons with chronic illnesses, it is essential to review efficacy and adverse effects of complementary and alternative therapies.