Effect of pulsed electromagnetic field therapy in patients undergoing total knee arthroplasty: a randomised controlled trial

Purpose

It has been reported that even one year after total knee arthroplasty (TKA), a relevant percentage of patients does not attain complete recovery and indicate unfavourable long-term pain outcome. We compared the clinical outcome of 33 patients undergoing TKA randomly assigned to the control or the pulsed electromagnetic field group (I-ONE therapy).

Methods

I-ONE therapy was administered postoperatively four hours per day for 60 days. Patients were assessed before surgery and then at one, two and six months postoperatively using international scores.

Results

One month after TKA, pain, knee swelling and functional score were significantly better in the treated compared with the control group. Pain was still significantly lower in the treated group at the six month follow-up. Three years after surgery, severe pain and occasional walking limitations were reported in a significantly lower number of patients in the treated group.

Conclusions

Advantages deriving from early control of joint inflammation may explain the maintenance of results at follow-up. I-ONE therapy should be considered an effective completion of the TKA procedure.     

脉冲电磁场对接骨板性骨质疏松的影响

我们对钢板固定家兔胫骨用ＰＥＭＦｓ进行治疗 ,观察固定骨段的骨孔隙率 ,骨矿含量和矿化沉积率的变化 ,以期为临床应用ＰＥＭＦｓ防治接骨板性骨质疏松提供依据。1　材料与方法1 1　动物　健康成年大耳白家兔 18只 ,雌雄不限 ,体重在 2 5～ 3 0ｋｇ(河南医科大学实验动物中心提供 )。标准全价营养饲料分笼喂养。1 2　接骨板　采用天津产 4孔 316Ｌ不锈钢掌骨接骨板。1 3　仪器　ＴＦ ＶＩ型中医多功能治疗仪由郑州市颈肩腰腿痛医院研究所提供 (专利号 :992 385 4 2 3)。1 4　分组与处理　动物随机分为Ａ、Ｂ、Ｃ三组 ,每组各 6只。Ａ组为…     

Modulation of bone loss during disuse by pulsed electromagnetic fields

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

脉冲电磁场对MC3T3-E1细胞增殖与分化的影响

目的研究不同强度50Hz脉冲电磁场(Pulse electromagnetic fields,PEMFs)对小鼠成骨细胞系MC3T3-E1增殖与分化的影响。方法 MC3T3-E1传代培养后分成七组,分别采用0.0 m T、0.6 m T、1.2 m T、1.8 m T、2.4 m T、3.0 m T和3.6 m T 50 Hz脉冲电磁场处理,90 min/d。MTT法检测细胞增殖情况,成骨性分化检测处理3 d、6 d、9 d、12 d后ALP活性和首次处理12 h后BMP-2、Runx-2、OPG基因表达情况。结果 6种强度的脉冲电磁场均促进细胞增殖,其中0.6 m T的促增殖效应最强(P<0.01)。在成骨性诱导培养条件下,细胞内ALP活性随电磁场处理时间的延长而逐渐增加,第9 d达到峰值,之后开始回落。0.6 m T、3.0 m T和3.6 m T均能提高ALP活性,其中0.6 m T始终处于最高水平(P<0.01)。三种基因的表达水平在首次处理12 h,在0.6 m T、1.2 m T、3 m T和3.6 m T组均显著提高,但仍然是0.6 m T的增强效应最为明显。结论 0.6 m T 50 Hz脉冲电磁场具有最佳的促进MC3T3-E1细胞增殖和成骨性分化活性,这可能为采用脉冲电磁场治疗骨质疏松症提供了理想的治疗参数。     

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

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

Pulsed electromagnetic fields reduce knee osteoarthritic lesion progression in the aged Dunkin Hartley guinea pig.

An experimental in vivo study was performed to test if the effect of Pulsed Electromagnetic Fields (PEMFs) on chondrocyte metabolism and adenosine A2a agonist activity could have a chondroprotective effect on the knee of Dunkin Hartley guinea-pigs of 12 months with spontaneously developed osteoarthritis (OA). After a pilot study, 10 animals were randomly divided into two groups: PEMF-treated group (6 h/day for 3 months) and Sham-treated group. Microradiography and histomorphometry were performed on the entire articular surface of knee joints used in evaluating chondropathy severity, cartilage thickness (CT), cartilage surface Fibrillation Index (FI), subchondral bone plate thickness (SBT) and histomorphometric characteristics of trabecular epiphyseal bone. The PEMF-treated animals showed a significant reduction of chondropathy progression in all knee examined areas (p<0.05). CT was significantly higher (p<0.001) in the medial tibia plateaus of the PEMF-treated group when compared to the Sham-treated group. The highest value of FI was observed in the medial tibia plateau of the Sham-treated group (p<0.05). Significant lower values were observed in SBT of PEMF-treated group in comparison to Sham-treated group in all knee examined areas (p<0.05). The present study results show that PEMFs preserve the morphology of articular cartilage and slower the progression of OA lesions in the knee of aged osteoarthritic guinea pigs. The chondroprotective effect of PEMFs was demonstrated not only in the medial tibial plateau but also on the entire articular surface of the knee.     

The effects of pulsed electromagnetic fields on blood vessel growth in the rabbit ear chamber.

A double-blind, controlled trial of the effects of pulsed electromagnetic fields on capillary growth in the rabbit ear chamber in adult New Zealand white rabbits has been performed. Three waveforms have been investigated. The first, a pulse burst waveform, produced a significant increase in the rate of growth of the vascular tissue within the chamber, but had no effect on macroscopic tissue maturation. The second and third, two different single pulse waveforms, had, in contrast, no significant effect on the rate of vascular growth and only an effect on vessel characteristics, with increased maturation of vessels using the second waveform. It is concluded that some of the observed effects of pulsed electromagnetic fields on tissue healing may be mediated through a primary effect on vascular growth.     

脉冲电磁场促进人骨髓间充质干细胞成骨的研究

目的 :观察脉冲电磁场 (PEMFs)对人骨髓间充质干细胞 (hMSCs)成骨能力的影响。方法 :hMSCs受频率 12Hz、场强 1.1mT的PEMFs刺激 8h/d ,检测细胞增殖、细胞周期 ,观察细胞超微结构、骨钙素、Ⅰ型胶原免疫组化染色 ,碱性磷酸酶 (ALP)活性、核固红钙染色。结果 :脉冲电磁场作用后的细胞增殖能力提高 ,细胞形态发生变化 ,透射电镜观察提示细胞成熟 ,核固红钙染色、骨钙素、Ⅰ型胶原免疫组化染色均阳性 ,ALP活性增高。结论 :hMSCs经合理的PEMFs体外刺激后 ,细胞增殖加速 ,符合成骨细胞的形态特征和生物学特性。     

低强度脉冲电磁场对去卵巢大鼠不同部位骨密度的影响

目的 探讨低强度脉冲电磁场(PEMFs)对去势雌性大鼠不同部位骨密度的影响.方法 30只10月龄雌性SD大鼠随机分为3组:一组去势造模(造模组),另一组行假手术(空白组),第三组去势造模后暴露于50 Hz、0.16 mT的磁场环境下60 min/d,共90天(磁疗组).实验期间动态观察大鼠全身及颅骨骨密度,期满处死后测定血清雌二醇水平及骨密度.结果 ①空白组雌激素水平和子宫系数均显著高于其他两组(P<0.01);②至60天时,空白组、磁疗组的颅骨骨密度显著高于造模组(P<0.05),全身骨密度在90天时才出现统计学意义(P<0.05);③与空白组和磁疗组相比,造模组椎体骨密度(P<0.01)比腰椎骨密度(P<0.05)差异更显著,磁疗组股骨骨密度虽较造模组有所上升但差异未达到统计学意义.结论 全身骨密度与颅骨骨密度结合可有效评估大鼠活体骨密度动态变化;PEMFs对因去势造成的骨密度下降有明显抑制作用,且对不同部位骨密度影响程度不同;采用去椎弓的单一椎体为骨密度衡量点能更为敏感的反映治疗效果.     

Degradative pathways in cultured synovial fibroblasts: selective effects of pulsed electromagnetic fields

A cell culture model for studying the cytokine-mediated degradation of connective tissue was exposed to clinically applied, low-frequency pulsed electromagnetic fields (PEMF), and levels of collagenolytic activity, two lysosomal hydrolases, and prostaglandin E2 were measured. PEMFs reduced the release of two lysosomal enzymes by cultured rabbit synovial fibroblasts but did not affect their response to mononuclear-cell-conditioned medium. PEMF did not alter levels of cytokine activity produced by a mixed mononuclear cell population, nor did they affect the cytokine-mediated release of collagenase or prostaglandin E2 by synovial fibroblasts. The relevance of these findings to the clinical application of PEMF to soft- and hard-tissue injuries is discussed.     

不同频率脉冲电磁场对骨保护素基因敲除小鼠骨代谢指标影响

目的采用不同频率的脉冲电磁场干预骨保护素基因敲除小鼠骨质疏松模型,探讨脉冲电磁 场治疗骨质疏松的最适治疗频率。方法8周龄雌雄各半骨保护素基因敲除小鼠30只,随机分为 A、B、C 3组,每组10只,粤组为空白对照组,不进行干预;B组小鼠每天在强度为4皂栽,频率为8 HZ 的磁场中照射治疗20 min,共30 d;C组小鼠每天在强度为4 mT,频率为32 HZ的磁场中照射治疗20 min,共30凿。各组小鼠在治疗前及治疗30d后用酶联免疫法（ELISA )法检测抗酒石酸酸性磷酸酶 缘遭及血清骨钙素值。结果8HZ、32HZ两治疗组在治疗后抗酒石酸酸性磷酸酶5遭,血清骨钙素含 量与A对照组之间比较差异有统计学意义（P <0.05 ), 8 HZ、32 HZ两治疗组之间治疗前与治疗后所 测三种指标比较差异无统计学意义（P >0.05 )。结论脉冲电磁场对骨保护素基因敲除小鼠骨质疏 松有肯定治疗效果,应用频率为8-32 HZ的磁场治疗能产生相同的治疗效果。     

The effect of pulsed electromagnetic fields on bone cell metabolism and calvaria resorption in vitro,and on calcium metabolism in the live rat

Summary The effects of three pulsed electromagnetic fields were investigated on bone cells and calvaria in culture, and on calcium metabolism in the live rat. No significant effect was seen on: 1) the proliferation of calvaria cells in culture; 2) alkaline phosphatase level, lactic acid release and collagen synthesis by confluent calvaria cells, with the exception of one pulse which produced a small increase in the latter when expressed as DNA; 3) resorption of calvaria in culture; 4) intestinal absorption, urinary excretion and net balance of calcium, bone formation and bone resorption in the live rat.on leave from Department of Pharmacology, School of Dentistry, Tokyo Medical and Dental University, Tokyo, Japan     

The effect of pulsed electromagnetic fields on the osteointegration of hydroxyapatite implants in cancellous bone: a morphologic and microstructural in vivo study.

Effects of pulsed electromagnetic fields (PEMFs, 75 Hz. 1.6 mT) were investigated in 12 rabbits after placing hydroxyapatite (HA) implants in their femoral condyles. Six animals were stimulated with PEMFs for three consecutive weeks, 6 h/day, while the remaining animals were sham-treated (Control Group). Rabbits were sacrificed at 3 and 6 weeks (after a 3-week non-stimulation period) for histomorphometric analysis and microhardness testing (at 200, 500, 1,000, 2,000 microm from the implant) around the implants. Histomorphometric analysis did not highlight any significant changes. On the contrary, there were statistically significant differences between the effects produced by PEMFs and Control Groups (F = 149.70, p < 0.0005) on the Affinity Index results, as well as by the experimental time of 6 and 3 weeks (F = 17.12, p = 0.001) on the same results. In PEMF-stimulated animals the microhardness (HV) values measured in trabecular bone at a distance of 200 and 500 microm from the implants, were significantly higher with respect to controls. At 6 weeks, HV values at the bone-implant interface in PEMF-stimulated animals were not significantly different with respect to normal bone, while they remained significantly lower in control animals. Both morphological and structural results demonstrated a positive therapeutic effect of PEMFs in accelerating HA osteointegration in trabecular bone.     

低频脉冲电磁场治疗骨质疏松症的现状和展望

骨质疏松症是目前全球性的公共卫生问题。脉冲电磁场对骨质疏松病人的慢性骨痛,腰背疼痛,以及陈旧性骨折造成的疼痛有明显的缓解作用,同时有改善睡眠等作用。作用机制包括促进毛细血管增生,增加血浆β-内啡肽的含量以及降低血清前列腺素水平来达到镇痛作用。脉冲电磁场可以影响细胞膜的钙离子通道,加速了钙在组织中的沉积;直接或间接作用促进成骨细胞增殖;以及加速破骨细胞凋亡来增加骨密度等。     

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

Summary Primary and passaged cultures of fibroblasts (RBMFs) raised from the bone marrow stroma of young rabbits were treated with pulsed electromagnetic fields (PEMFs) from the start of each culture until 1 week after they became confluent. The PEMF treatment had no effect on cell proliferation, estimated by phase contrast microscopy, by³H-thymidine incorporation into DNA, or by total DNA assay. Collagen production, estimated by conversion of³H-proline to³H-hydroxy-proline in nondialyzable material was markedly elevated in postconfluent cultures, but not in cultures that had only just reached confluence. About 65% of³H-hydroxyproline was in low molecular weight form, and a correlation between collagen break-down and cyclic AMP (cAMP) levels in RBMFs was demonstrated by adding dibutyryl cAMP or prostaglandin E₂ (PGE₂) to the culture medium concurrently with³H-proline. The PEMF apparatus caused an insufficient temperature rise (less than 0.1°C) to account for these results. We propose that the rise in collagen production is consistent with the hypothesis that PEMFs act by reducing cAMP levels in RBMFs, and that thermal effects are insignificant.     

Comments on the use of electromagnetic fields in biological studies

Summary For biological or cellular experiments using electromagnetic fields it is essential that the parameters defining the field be accurately specified if the results are to be meaningful and are to be compared with the same experiment conducted in a different laboratory. The interaction of living systems with electric and magnetic fields can some only through forces exerted on the charges on the system. If the charges are stationary the only origin of the force is the electric field. The electric field may be established by charge distributions, as in “capacitative plate” experiments, or by time-varying magnetic fields. A geometry commonly used to produce time-varying magnetic fields consists of a pair of coaxial coils each of equal radius and separated by a distance about equal to the radius. The electric field induced by a varying current in such a pair of coils varies both in space and in time. The field is always zero on the axis of symmetry, and increases to a maximum near the radius of the coils. The strength is proportional to the time-rate-of-change of the current in the coil, which depends not only on the amplitude and shape of the voltage pulse applied to the coil but also on the resistance and inductance of the coil. The purpose of this note is to describe how the important physical parameters may be determined.     

126例骨质疏松患者的疼痛与脉冲电磁场疗效的初步分析

目的 分析原发性骨质疏松患者疼痛的特点，探讨脉冲电磁场治疗疼痛的疗效。方法 分析126例原发性骨质疏松患者疼痛的部位、性质、程度和持续时间，采用BGl00型骨质疏松治疗仪产生的脉冲电磁场(PEMFs)进行治疗。结果 原发性骨质疏松患者疼痛以下腰背及下肢区域为多见，性质以钝痛为主。PEMFs对I型骨质疏松患者止痛的效果比Ⅱ型患者更为迅速显著。结论 PEMFs为一种安全而有效的治疗骨质疏松症患者疼痛的方法。     

脉冲电磁场影响人骨髓基质干细胞缝隙连接通讯的实验研究

目的研究脉冲电磁场(PEMFs)对人骨髓基质干细胞(hBMSCs)缝隙连接所介导细胞间通讯(GJIC)的影响。方法透射电镜观察BMSCs超微结构,应用荧光漂白恢复(FRAP)技术,通过激光共聚焦显微镜检测hBM-SCs经PEMFs刺激后GJIC的功能变化。结果经PEMFs刺激后的hBMSCs,平均荧光漂白恢复率为(64.12±0.83)%,较对照组犤(35.26±0.76)%犦有显著性增加(P<0.05)。结论PEMFs刺激能促进hBMSCs的缝隙连接通讯功能。     

踝关节置换术治疗创伤性关节炎的近期疗效报告

目的探讨STAR型假体进行踝关节置换治疗严重的踝关节炎的方法,及其近期疗效.方法2003年11月至2004年6月,我们共施行踝关节置换手术治疗晚期骨性关节炎4例,病程平均为7年(2～10年).按Kofoed踝关节评分系统分别进行术前、术后的踝关节疼痛、活动度,功能评分,观察其疗效.结果所有病例均获得随访(1～2.5年,平均2年).术后随访时的Kofoed踝关节评分较术前明显提高,疗效评定均为优.结论应用STAR型假体进行踝关节置换是治疗严重踝关节炎的有效手段,近期疗效满意,可明显解除踝关节疼痛.     

脉冲电磁场对去势大鼠骨髓源细胞体外培养破骨细胞变化的影响

目的：观察脉冲电磁场对去势大鼠骨髓源性破骨细胞样细胞（OLC）形成变化及凋亡的影响。方法：30只健康3月龄雌性Wistar大鼠,随机分为A组（双侧卵巢切除＋磁场治疗组、18只）、B组（双侧卵巢切除组、6只）和C组（伪去势组、6只）。A组又随机均分3组：A1、A2、A3组,电磁场频率分别为1.5、2、75Hz。术后单纯喂养3个月后对各组大鼠骨髓细胞进行培养,培养2d后,A1、A2、A3组置脉冲电磁场治疗,1次/d,每次30min,共治疗2周。之后各组培养细胞作瑞氏-吉姆萨、抗酒石酸酸性磷酸酶（TRAP）和Hoechst 33258染色,观察破骨细胞变化并计数。结果：大鼠骨髓体外培养细胞TRAP染色结果显示,C组的破骨细胞形成数量最少,其次为A2、A3、A1、B组。B组的破骨细胞形成数量与C组和A2组比较显著增多（P〈0.01）,B组的破骨细胞形成数量与A1、A3组比较明显增多（P〈0.05）。Hoechst 33258染色结果显示,C组破骨样细胞凋亡出现数量较多,C、A2组凋亡数明显多于B组（P〈0.05）。结论：脉冲电磁场能使大鼠骨髓体外培养破骨细胞形成数量减少、凋亡数增加,频率为2Hz的效果最佳,表明脉冲电磁场可能将是骨质疏松症治疗的新方法。