BlueCross and BlueShield of Montana Medical Policy/Codes
Electrical Bone Growth Stimulation (EBGS)
Chapter: Durable Medical Equipment
Current Effective Date: February 15, 2014
Original Effective Date: December 18, 2009
Publish Date: January 31, 2014
Revised Dates: April 17, 2012; November 07, 2012; October 24, 2013; January 31, 2014
Description

Both invasive and noninvasive electrical bone growth stimulators have been investigated as an adjunct to spinal fusion surgery, with or without associated instrumentation, to enhance the chances of obtaining a solid spinal fusion. Noninvasive devices have also been investigated to treat a failed fusion.

In the appendicular skeleton, electrical stimulation has been primarily used to treat tibial fractures, and thus this technique has often been thought of as a treatment of the long bones. According to orthopedic anatomy, the skeleton consists of long bones, short bones, flat bones, and irregular bones. Long bones act as levels to facilitate motion, while short bones function to dissipate concussive forces. Short bones include those composing the carpus and tarsus. Flat bones, such as the scapula or pelvis, provide a broad surface area for attachment of muscles.

Despite their anatomic classification, all bones are composed of a combination of cortical and trabecular (also called cancellous) bone. Each bone, depending on its physiologic function, has a different proportion of cancellous to trabecular bone. At a cellular level, however, both bone types are composed of lamellar bone and cannot be distinguished microscopically.

Regulatory Status

Implantable bone growth stimulations that have received U.S. Food and Drug Administration (FDA) premarket approval (PMA):

  • The OsteoStim® (Electro-Biology, Inc.), which may also be marketed under the trade name SPF (Biomet), has received FDA PMA.

Noninvasive bone growth stimulators that have received FDA PMA include:

  • The SpinalPak® bone growth stimulator system from Biolectron (a subsidiary of Electro-Biology, Inc., Parsippany, NJ) is a capacitive coupling system, received PMA in 1999 for use as an adjunct to primary lumbar spinal fusion at 1 or 2 levels.
  • The EBI Bone Healing System® from Biolectron (a subsidiary of Electro-Biology, Inc., Parsippany, NJ) is a pulsed electromagnetic field system which was first approved in 1979 with FDA PMA and indicated for nonunions, failed fusions, and congenital pseudoarthroses. The device is secured with a belt around the waist.
  • SpinaLogic Bone Growth Stimulator® (Regentek, a division of dj Orthopedics, LLC (formerly OrthoLogic, Tempe, AZ) received PMA in 1994 as a combined magnetic field portable device. This device is secured with a belt around the waist.
  • Spinal-Stim Lite ® (Orthofix, Inc., Richardson, TX) received PMA in 1996 as a spinal adjunct to the Physio-Stim®. This device was approved to increase the probability of fusion success and as a nonoperative treatment for the salvage of failed spinal fusion, where a minimum of 9 months has elapsed since the last surgery.
  • The Cervical-Stim® from Orthofix, Inc., Richardson, TX is a pulsed electromagnetic field system that was approved in 2004 as an adjunct to cervical fusion surgery in patients at high risk for nonfusion.
  • The noninvasive OrthoPak® Bone Growth Stimulator (BioElectron) received U.S. Food and Drug Administration (FDA) premarket approval in 1984 for treatment of fracture nonunion.
  • Pulsed electromagnetic field systems with FDA premarket approval (all noninvasive devices) include Physio- Stim® from Orthofix Inc., first approved in 1986, and OrthoLogic® 1000, approved in 1997, both indicated for treatment of established nonunion secondary to trauma, excluding vertebrae and all flat bones, in which the width of the nonunion defect is less than one-half the width of the bone to be treated; No distinction was made between long and short bones.

The FDA has approved labeling changes for electrical bone growth stimulators that remove any timeframe for the diagnosis.

No semi-invasive electrical bone growth stimulator devices were identified with FDA approval or clearance.

Electrical and electromagnetic fields can be generated and applied to bones through the following methods:

  • Surgical implantation of a cathode at the fracture site with the production of direct current (DC) electrical stimulation. Invasive devices require surgical implantation of a current generator in an intramuscular or subcutaneous space, while an electrode is implanted within the fragments of bone graft at the fusion site. The implantable device typically remains functional for 6 to 9 months after implantation, and, although the current generator is removed in a second surgical procedure when stimulation is completed, the electrode may or may not be removed. Implantable electrodes provide constant stimulation at the nonunion or fracture site but carry increased risks associated with implantable leads.
  • Noninvasive electrical bone growth stimulators generate a weak electrical current within the target site using pulsed electromagnetic fields, capacitive coupling, or combined magnetic fields. In capacitive coupling, small skin pads/electrodes are placed on either side of the fusion site and worn for 24 hours per day until healing occurs or up to 9 months. In contrast, pulsed electromagnetic fields are delivered via treatment coils that are placed over the skin and are worn for 6–8 hours per day for 3 to 6 months. Combined magnetic fields deliver a time-varying magnetic field by superimposing the time-varying magnetic field onto an additional static magnetic field. This device involves a 30-minute treatment per day for 9 months. Patient compliance may be an issue with externally worn devices.
  • Semi-invasive (semi-implantable) stimulators use percutaneous electrodes and an external power supply obviating the need for a surgical procedure to remove the generator when treatment is finished.

Nonunion

The definition of a fracture nonunion has remained controversial. The original U.S. Food and Drug Administration (FDA) labeling defined nonunion as follows: "A nonunion is considered to be established when a minimum of 9 months has elapsed since injury and the fracture site shows no visibly progressive signs of healing for minimum of 3 months." Others have contended that 9 months represents an arbitrary cut-off point that does not reflect the complicated variables that are present in fractures, i.e., degree of soft tissue damage, alignment of the bone fragments, vascularity, and quality of the underlying bone stock. Other proposed definitions of nonunion involve 3 to 6 months’ time from original healing, or simply when serial x-rays fail to show any further healing.

Delayed Union

Delayed union is defined as a decelerating healing process as determined by serial x-rays, together with a lack of clinical and radiologic evidence of union, bony continuity, or bone reaction at the fracture site for no less than 3 months from the index injury or the most recent intervention. When lumped together, delayed union and nonunion are sometimes referred to as "ununited fractures." 

Fresh Fracture

A fracture is most commonly defined as “fresh” for 7 days after the fracture occurs. Most fresh closed fractures heal without complications with the use of standard fracture care, i.e., closed reduction and cast immobilization.

Policy

Each benefit plan, summary plan description or contract defines which services are covered, which services are excluded, and which services are subject to dollar caps or other limitations, conditions or exclusions.  Members and their providers have the responsibility for consulting the member's benefit plan, summary plan description or contract to determine if there are any exclusions or other benefit limitations applicable to this service or supply.  If there is a discrepancy between a Medical Policy and a member's benefit plan, summary plan description or contract, the benefit plan, summary plan description or contract will govern.

Coverage

Invasive or noninvasive methods of electrical bone growth stimulation (EBGS) as an adjunct to spinal fusion surgery may be considered medically necessary for patients at high risk for failed fusion, as indicated by one of the following:

  • One or more previous failed spinal fusion(s); OR
  • Grade III or worse spondylolisthesis; OR
  • Fusion to be performed at more than one level; OR
  • Current smoking habit; OR
  • Diabetes; OR
  • Renal disease; OR
  • Alcoholism, OR
  • Steroid use.

Note:  Failed spinal fusion is defined as a spinal fusion that has not healed at a minimum of six months after the original surgery, as evidenced by serial x-rays over a course of three months.

Spinal noninvasive EBGS may be considered medically necessary as a treatment of patients with failed spinal fusion.

Non-spinal noninvasive EBGS may be considered medically necessary for:

  • Delayed unions* of fractures or failed arthrodesis at high-risk sites (i.e., open or segmental tibial fractures, carpal navicular fractures), OR
  • Failed fusions, congenital pseudarthrosis and fracture nonunions (where there is no evidence of progression of healing for 3 or more months despite appropriate fracture care).

Note:  *Delayed union is defined as a decelerating healing process as determined by serial x-rays, together with a lack of clinical and radiologic evidence of union, bony continuity, or bone reaction at the fracture site for no less than 3 months from the index injury or the most recent intervention.

All other methods and indications for EBGS, including but not limited to the following are considered experimental, investigational, and/or unproven:

  • Treatment of fresh fractures (<14 days); OR
  • Semi-invasive (semi-implantable) electrical stimulation including but not limited to use as an adjunct to lumbar fusion surgery and for failed lumbar fusion, OR
  • Stress fractures

Rationale

This policy was originally developed in 2009 and has been updated with searches of scientific literature through December 2013.  This section of the current policy has been substantially revised. The following is a summary of the key literature to date.

Spinal

The information regarding electrical bone stimulation as an adjunct to spinal fusion surgery or as a treatment of failed spinal fusion surgery (i.e., salvage therapy) was initially based on 2 TEC Assessments (1, 2)  The initial TEC Assessments (1, 2) offered the following conclusions:

  • Data from a randomized, controlled clinical trial of patients meeting the criteria for high risk for development of failed fusion suggest that invasive or noninvasive electrical bone stimulation, as an adjunct to spinal fusion surgery is associated with a significantly higher spinal fusion success rate in the treated group compared with the control group. (3, 4)
  • Data from uncontrolled studies of patients with failed spinal fusion suggest that noninvasive electrical stimulation results in a significantly higher fusion rate. The lack of controlled clinical trials is balanced by the fact that these patients served as their own control.

Implantable Electrical Stimulation

Instrumented Spinal Fusion

Kucharzyk reported on a controlled prospective nonrandomized trial of implantable electrical stimulation in patients undergoing instrumented posterior spinal fusion with pedicle screws. (5) A series of 65 patients who did not use electrical stimulation were compared with a later series of similar patients who did receive implantable electrical stimulation. Fusion success was 95.6% in the stimulated group compared to 87% in the nonstimulated group, a statistically significant difference. It appears that all patients had at least 1 or more high-risk factors for failed fusion, i.e., smoking history, prior surgery, multiple fusion levels, diabetes, etc. While this trial supports the use of electrical stimulation as an adjunct to instrumented posterior lumber fusion, it did not specifically identify the outcomes in patients considered to be at low risk for failed fusion. Rogozinski and Rogozinski reported on the outcomes of 2 consecutive series of patients undergoing posterolateral fusions with autologous bone graft and pedicle screw fixation. (6) The first series of 41 patients were treated without electrical stimulation, while the second group of 53 patients received invasive electrical stimulation. Those receiving electrical stimulation reported a 96% fusion rate, compared to an 85% fusion rate in the unstimulated group. The fusion rate for patients receiving stimulation versus no stimulation was also significantly higher among those considered at high risk due to previous back surgery or multiple fusion levels. No significant increase in the fusion rate was noted among nonsmokers (i.e., without a risk factor), but the comparative fusion rates for all patients without high-risk factors is not presented.

Noninstrumented Spinal Fusion

In 2009, Andersen et al. published 2-year radiographic and functional outcomes from a European multicenter randomized controlled trial (RCT) of direct current (DC) stimulation with the SpF-XL IIb for posterolateral lumbar spinal fusion (PLF) in 98 patients older than age 60 years. (7, 8) This age group has decreased fusion potential. In addition, instrumentation was not used due to risks related to longer operating times and screw loosening due to osteoporosis. All patients received fresh frozen allograft bone mixed with autograft obtained from the decompression procedure and were braced for 3 months after surgery. Dummy electrodes were placed in the control group to allow blinded radiographic evaluation, but patients and surgeons were not blinded to treatment group. Stimulator-specific complications included 3 cases of hematoma after removal of the battery and 2 patients who had pain at the site of the subcutaneous pocket. Three patients dropped out before the 1-year radiologic evaluation, 1 patient died, and an additional 25 patients did not complete the functional outcome questionnaires, resulting in 70% follow-up at 2-years. The percentage of dropouts was similar for the 2 treatments; patients who missed their 2-year evaluation had poorer outcomes on the Dallas Pain Questionnaire at the 1-year follow-up. Blinded evaluation of fusion by computed tomography (CT) scan indicated the same low percentage of cases with fusion in the 2 groups (33%). Fusion rates by plain radiographs were 57% in the control group (24/42) and 64% in the standard DC-stimulation group (27/42). Patients who achieved a solid fusion had better functional outcome and pain scores at their latest follow-up. At 2-year follow-up, electrical stimulation was associated with improved functional outcomes on 3 of 4 Dallas Pain Questionnaire subscales (daily activity, work/leisure, and social interest) but not for the Low Back Pain Rating Scale or the validated Short Form (SF)-36. These functional results have a high potential for bias due to the dropout of patients who had poorer outcomes and unequal patient expectation in this unblinded study.

In a 2010 publication, Anderson et al. evaluated bone quality of the fusion mass in 80 of the patients described above (82% of 98) who underwent dual energy x-ray absorptiometry (DEXA) scanning to evaluate bone mineral density (BMD) at the 1-year follow-up. (9) This report describes 40 (n=46) and 100 (n=8) microAmp DC stimulation compared with a nonstimulated control condition (n=36). Fusion rates determined by CT scanning at the 2-year follow-up were 34% in the control group and 33% and 43% in the 40 and 100 microAmp groups, respectively (not significantly different). Patients classified as fused after 2 years had significantly higher fusion mass BMD at 1 year (0.592 vs. 0.466 g/cm2), but DC electrical stimulation did not improve fusion mass bone quality (0.483 g/cm2 for 40 microAmp; 0.458 g/cm2 for 100 microAmp; 0.512 g/cm2 for controls). Using linear regression, fusion mass bone quality was significantly influenced by gender, age of the patient, bone density of the remaining part of the lumbar spine, amount of bone graft applied, and smoking.

No studies of semi-invasive (semi-implantable) stimulators were identified during the most recent literature search of MEDLINE through July 2011. In addition, none of these devices has U.S. Food and Drug Administration (FDA) clearance or approval. Thus, use of these devices is considered investigational.

Noninvasive Electrical Stimulation

Lumbar Spine

Goodwin and colleagues reported on the results of a study that randomly assigned 179 patients undergoing lumbar spinal fusions to receive or not receive capacitively coupled electrical stimulation. (10) A variety of surgical procedures both with and without instrumentation were used, and subjects were not limited to high-risk patients. The overall successful fusion rate was 84.7% for those in the active group compared to 64.9% in the placebo group, a statistically significant difference. While the actively treated group reported increased fusion success for all stratification groups (i.e., according to fusion procedure, single or multilevel fusion, smoking or nonsmoking group), in many instances, the differences did not reach statistical significance because of small numbers. For example, the subgroups in which there was not a significant difference in fusion between the active and placebo groups included patients who had undergone previous surgery, smokers, and those with multilevel fusion. In addition, there were numerous dropouts in the study and a 10% noncompliance rate with wearing the external device for up to 9 months.

Mooney reported on the results of a double-blind study that randomly assigned 195 patients undergoing initial attempts at interbody lumber fusions with or without fixation to receive or not receive pulsed electromagnetic field electrical stimulation. (4) Patients were not limited to high-risk groups. In the active treatment group, the success rate was 92%, compared to 65% in the placebo group. On subgroup analysis, the treated group consistently reported an increased success rate. Subgroups included graft type, presence or absence of internal fixation, or presence or absence of smoking.

Linovitz and colleagues conducted a double-blind clinical trial that randomly assigned 201 patients undergoing 1- or 2-level posterolateral fusion without instrumentation to undergo active or placebo electrical stimulation using a combined magnetic field device. (11) Unlike capacitively coupled or pulsed electromagnetic field devices, the combined magnetic field device requires a single 30-minute treatment per day with the device centered over the fusion site. Patients were treated for 9 months. Among all patients, 64% of those in the active group showed fusion at 9 months compared to 43% of those with placebo devices, a statistically significant difference. On subgroup analysis, there was a significant difference among women, but not men.

Mooney and Linovitz et al. excluded from their studies patients with severe osteoporosis, and Goodwin et al. excluded patients with osteoporosis of unspecified severity. (4, 10, 11) None of the studies mentioned steroid use; however, authors of two papers summarizing the available evidence on inhibition of bone healing (12) and the effects of drugs on bone healing (13) agree that long-term (longer than 1 week) steroid use has an inhibitory effect on bone healing. Thus, steroid use is added as an additional condition that results in high risk of nonfusion.

Cervical Spine

In 2008, Foley et al. published results of the industry-sponsored investigational device exemption (IDE) study of pulsed electromagnetic field (PEMF) stimulation as an adjunct to anterior cervical discectomy and fusion (ACDF) with anterior cervical plates and allograft interbody implants. (14, 15) This study described results using the Cervical-Stim device from Orthofix that received premarket approval (PMA) from the FDA in 2004. A total of 323 patients were randomized, 163 to PEMF and 160 to no stimulation. All patients were active smokers (more than 1 pack of cigarettes per day, 164 patients) or were undergoing multilevel ACDF (192 patients). Patients with pertinent history of trauma, previous posterior cervical approach or revision surgery, and certain systemic conditions or steroid use, and regional conditions such as Paget’s disease or spondylitis were excluded. Beginning 1 week after surgery, patients in the treatment group wore the Cervical-Stim device for 4 hours per day for 3 months.

Efficacy was measured by radiographic analysis at 1, 2, 3, 6, and 12 months. At 6 months, 122 patients in the treatment group and 118 in the control group were evaluable; 15 in the PEMF group and 13 in the control group voluntarily withdrew, 7 in the PEMF group and 1 control violated study protocol, and 19 in the PEMF group and 28 controls had radiographs that were not evaluable or radiographs that were not done within 2 weeks of the 6-month postoperative window. Fusion rates for the 240 (74%) evaluable patients at 6 months were 83.6% for the PEMF group and 68.6% for the control group (p=0.0065). By intent-to-treat (ITT) analysis, assuming that nonevaluable patients did not have fusion, PEMF and control groups fusion rates were 65.6% and 56.3%, respectively; these rates were not significantly different (p=0.0835). (FDA analysis, however, indicated that the results at 6 months were still statistically different in sensitivity analysis performed with the last observation carried forward or with all missing data imputed as nonfusion.) Of 245 patients available for follow-up at 12 months, fusion was achieved in 116 of 125 (92.8%) PEMF patients and 104 of 120 (86.7%) control patients; these rates were not significantly different (p=0.1129). Patient compliance, which was automatically monitored by the device, was assessed at each visit; however, compliance data were not included in the paper.

Clinical outcomes were not reported in the 2008 publication but were reported to the FDA. With clinical success defined as no worsening in neurologic function, an improvement in visual analogue scale (VAS) pain assessment, and no worsening in Neck Disability Index, the study found no significant difference between groups in the percent of subjects considered a clinical success at 6 months (p=0.85) or 12 months (p=0.11). The marginal difference in fusion rates by ITT analysis at 6 months, nonsignificant difference in fusion rates at 12 months, and lack of difference in functional outcomes at either 6 or 12 months do not support the efficacy of this device.

The single other report of electrical stimulation as an adjunct to cervical fusion identified in searches of the MEDLINE database performed through August 2012 is a case report from 2004 that describes treatment with pulsed electromagnetic field stimulation for delayed union of anterior cervical fusion. (16)

Section Summary

Evidence from randomized controlled trials suggests that electrical stimulation leads to higher fusion rates for patients undergoing spinal surgery. Interpretation of clinical trial data is limited by the heterogeneous populations studied and the variety of surgical procedures within the populations. Most patients in these studies were at high-risk for nonfusion, suggesting that the patients most likely to benefit are those at highest risk. The policy therefore indicates that electrical stimulation of the spine, whether invasive or noninvasive, should be limited to those patients with high-risk features. For patients at average risk for nonfusion, the scientific data are inadequate to determine the magnitude of benefit associated with electrical stimulation.

In addition, since there are no FDA-approved semi-invasive devices, these are considered investigational.

Practice Guidelines and Position Statements

The 2005 American Association of Neurological Surgeons and the Congress of Neurological Surgeons guideline states that there is Class II and III evidence (nonrandomized comparative trials and case series) “to support the use of direct current stimulation or capacitative coupled stimulation for enhancing fusion rates in high-risk patients undergoing lumbar PLF [posterolateral lumbar fusion]. A beneficial effect on fusion rates in patients not at "high risk" has not been convincingly demonstrated, nor has an effect been shown for these modalities in patients treated with interbody fusion. There is limited evidence both for and against the use of pulsed electromagnetic field stimulation (PEMFS) for enhancing fusion rates following PLF. Class II and III medical evidence supports the use of PEMFS for promoting arthrodesis following interbody fusion. Although some studies have purported to demonstrate functional improvement in some patient subgroups, other studies have not detected differences. All of the reviewed studies are significantly flawed by the use of a 4-point patient satisfaction scale as the primary outcome measure. This outcome measure is not validated. Because of the use of this flawed outcome measure and because of the conflicting results reported in the better-designed studies that assess functional outcome, there is no consistent medical evidence to support or refute use of these devices for improving patient outcomes.” (17)

Appendicular Skeleton

Noninvasive Bone Growth Stimulation

Nonunion

The policy regarding electrical bone stimulation as a treatment of nonunion of fractures of the appendicular skeleton is based on the labeled indications by the U.S. Food and Drug Administration (FDA). The FDA approval was based on a number of case series in which patients with nonunions, primarily of the tibia, served as their own control. These studies suggest that electrical stimulation results in subsequent unions in a significant percentage of patients. (19-23)

A 2008 systematic review of electromagnetic bone growth stimulation by Griffin and colleagues included 49 studies, 3 of which were randomized controlled trials (RCTs). (24) The 2 RCTs that included patients with nonunion and the single RCT that included patients with delayed union are described below.

A 1994 RCT by Scott and King compared capacitive coupled electric fields with sham treatment (dummy unit) in 23 patients with nonunion (fracture at least 9 months-old and without clinical or radiographic sign of progression to union within the last 3 months) of a long bone. (25) Patients with systemic bone disorders, synovial pseudoarthrosis, or fracture gap of greater than half the width of the bone were excluded. In this trial, electrodes were passed onto the skin surface through holes in the plaster cast. Twenty-one patients completed the protocol (10 treatment and 11 controls). Six months after beginning treatment, an orthopedic surgeon and a radiologist, neither of them involved in the patients’ management, examined radiographs and determined that 6 of 10 in the treatment group healed, while none of those in the control group healed (p=0.004).

In 2003, Simonis et al. compared pulsed electromagnetic field stimulation and placebo treatment for tibial shaft fractures ununited at least 1 year after fracture, no metal implant bridging the fracture gap, and no radiologic progression of healing in the 3 months before treatment. (26) All 34 patients received operative treatment with osteotomy and unilateral external fixator prior to randomization. Treatment was delivered by external coils. Patients were assessed monthly for 6 months, and clinical and radiographic assessments were conducted at 6 months. Treatment was considered a failure if union was not achieved at 6 months. In the treatment group, 89% of fractures healed compared with 50% in the control group (p=0.02). While a larger percentage of smokers in the treatment group healed than compared with those in the control group, the number of smokers in each group was not comparable, and the difference in healing rates between groups was not statistically significant. The authors conclude that the available evidence supports the use of pulsed electromagnetic field (PEMF) therapy in the treatment of nonunion of the tibia and suggest that future trials should consider which modality of electromagnetic stimulation and in which anatomical sites the treatment is most effective.

Delayed Union

Shi et al. reported a randomized sham-controlled trial that included 58 patients with delayed union of surgically-reduced long-bone fractures (femur, tibia, humerus, radius or ulna). (27) Delayed union was defined as a failure to heal after at least 16 weeks and not more than 9 months following surgical reduction and fixation of the fracture. Patients with fracture nonunion, defined as failure to heal after more than 9 months, were excluded from the study. Treatment with 8 hours of PEMF per day was stopped when no radiographic progression was observed over 3 months or when union was achieved, with union defined as no pain during joint stressing or during motion at the fracture site and callus bridging for 3 out of 4 cortices on blinded assessment. Three months of treatment resulted in a slight, but not statistically significant, improvement in the rate of union between PEMF-treated patients and controls (38.7% vs. 22.2%). The success rate was significantly greater with PEMF (77.4% vs. 48.1%) after an average of 4.8 months of treatment. The time to union was not significantly different between PEMF (4.8 months, range, 2 to 12) and sham controls (4.4 months, range 2 to 7).

In a double-blind RCT by Sharrard from 1990, PEMF stimulation was compared with a sham procedure using a dummy device in 45 patients with delayed union of the tibia. (28) Stimulators were positioned on the surface of the plaster cast. Treatment began 16 to 32 weeks after injury. Patients with fracture gaps greater than 0.5 cm after reduction, systemic disease, or taking steroids were excluded, as well as patients with marked bony atrophy or hypertrophy. Fifty-one patients were recruited, and 45 completed the protocol (20 treatment and 25 control). In the treatment group, 3 patients achieved union, 2 achieved probable union, 5 showed progression to union, and 10 showed no progress after 12 weeks. In the control group, none had united, 1 had probably united, 3 progressed toward union, and 17 showed no progress.

The policy regarding electrical stimulation of delayed unions is based on a 1992 TEC Assessment of the RCT by Sharrard, (29) which offered the following conclusions:

Sharrard reported radiographic evidence of healing at the end of the 12-week treatment period. Radiographs were rated separately by a radiologist and an orthopedic surgeon. Their inconsistent rating methods and uncertain comparability in their findings make the radiographic evidence difficult to interpret. In addition, it is uncertain whether radiographic evidence of healing after 12 weeks of treatment, an intermediate outcome, predicts health outcomes such as healing and need for subsequent surgery. In this study, there were no statistically significant differences between the active and sham groups on clinical outcomes such as movement at the fracture site, pain, and tenderness. Thus, Sharrard’s health outcome data do not show that noninvasive electrical bone growth stimulation delivers an advantage over placebo.

In 2011, Griffin et al. published a Cochrane review of electromagnetic field stimulation for treating delayed union or non-union of long bone fractures in adults. (30) In addition to the 3 RCTs reviewed above, the systematic review included a 1984 study by Barker et al. that randomized 17 participants with tibial non-union to electromagnetic field stimulation or sham treatment. (31) Thus, 4 studies with 125 participants were included for analysis. The primary outcome measure was the proportion of participants whose fractures had united at a fixed time point. For this outcome, the overall pooled effect size was small and not statistically significant (risk ratio [RR]: 1.96; 95% confidence interval [CI]: 0.86 to 4.48). Interpretation is limited due to the substantial clinical and statistical heterogeneity in the pooled analysis. In addition, there was no reduction in pain found in 2 trials, and none of the studies reported functional outcomes. The authors concluded that electromagnetic stimulation may offer some benefit in the treatment of delayed union and non-union.

Section Summary

Two randomized sham-controlled trials have been identified on the treatment of delayed union with PEMF. In the Sharrard study, radiographic healing was improved at 12 weeks, but there were no statistically significant differences between groups for clinical outcomes. In the study by Shi et al., only the rate of healing at an average of 4.8 months was statistically significant, and it is not clear if this is a prespecified endpoint. The time to healing was not reduced by PEMF.

Appendicular Skeletal Surgery

A comprehensive search found 2 small randomized controlled trials on non-invasive electrical bone growth stimulation after orthopedic surgery. In 1988, Borsalino et al. reported a randomized double-blind sham-controlled trial of pulsed electromagnetic field stimulation (8 hours a day) in 32 patients who underwent femoral intertrochanteric osteotomy for osteoarthritis of the hip. (32) Radiographic measurements at 90 days revealed significant increases in the periosteal bone callus and in trabecular bone bridging at the lateral, but not the medial cortex. The study is limited by the small sample size and the lack of clinical outcomes.

A 2004 trial randomized 64 patients (144 joints with triple arthrodesis or subtalar arthrodesis) to pulsed electromagnetic field stimulation for 12 hours a day or to an untreated control condition. (33) Patients at high risk of non-fusion (rheumatoid arthritis, diabetes mellitus, or on oral corticosteroids) were excluded from the study. Blinded radiographic evaluation found a significant decrease in the time to union (12.2 weeks for talonavicular arthrodesis vs. 17.6 weeks in the control group; 13.1 weeks for calcaneocuboid fusion vs. 17.7 weeks for the control group). Clinical outcomes were not assessed.

Fresh Fractures

A multicenter, double-blind, randomized sham-controlled trial evaluated 12 weeks of pulsed electromagnetic field stimulation for acute tibial shaft fractures. (34) The endpoints examined were secondary surgical interventions, radiographic union, and patient-reported functional outcomes.

Approximately 45% of patients were compliant with treatment (>6 hours daily use), and 218 patients (84% of 259) completed the 12-month follow-up. The primary outcome, the proportion of participants requiring a secondary surgical intervention because of delayed union or nonunion within 12 months after the injury, was similar for the 2 groups (15% active; 13% sham). Per protocol analysis comparing patients who actually received the prescribed dose of pulsed electromagnetic field stimulation versus sham treatment also showed no significant difference between groups. Secondary outcomes, which included surgical intervention for any reason (29% active; 27% sham), radiographic union at 6 months (66% active; 71% sham), and the SF-36 (Short Form) Physical Component Summary (44.9 active; 48.0 sham) and Lower Extremity Functional Scales at 12 months (48.9 active; 54.3 sham), also did not differ significantly between the groups. This sham-controlled RCT does not support a benefit for electromagnetic stimulation as an adjunctive treatment for acute tibial shaft fractures.

Another smaller (n=53) multicenter double-blind, randomized sham-controlled trial found no advantage of PEMF for the conservative treatment of fresh (<5 days from injury) scaphoid fractures. (35) Outcomes included the time to clinical and radiologic union and functional outcome.

Stress Fractures

In 2008, Beck et al. reported a well-conducted randomized controlled trial (n=44) of capacitively coupled electric fields (OrthoPak) for healing acute tibial stress fractures. (36) Patients were instructed to use the device for 15 hours each day and usage was monitored electronically. Healing was confirmed when hopping 10 cm high for 30 seconds was accomplished without pain. Although an increase in the hours of use per day was associated with a reduction in the time to healing, there was no difference in the rate of healing between treatment and placebo. Power analysis indicated that this number of patients was sufficient to detect a difference in healing time of 3 weeks, which was considered a clinically significant effect. Other analyses, which suggested that electrical stimulation might be effective for the radiologic healing of more severe stress fractures, were preliminary and a beneficial effect was not observed for clinical healing.

Invasive Bone Growth Stimulation

A comprehensive search for implantable bone stimulators identified a small number of case series, all of which focused on foot and ankle arthrodesis in patients at high risk for nonunion (summarized in reference (37). Risk factors for nonunion included smoking, diabetes mellitus, Charcot (diabetic) neuroarthropathy, steroid use, and previous nonunion. The largest case series described outcomes of foot or ankle arthrodesis in 38 high-risk patients. (38) Union was observed in 65% of cases by follow-up evaluation (n=18) or chart review (n=20). Complications were reported in 16 (40%) cases, including 6 cases of deep infection and 5 cases of painful or prominent bone stimulators necessitating stimulator removal. A multicenter retrospective review described outcomes from 28 high-risk patients with arthrodesis of the foot and ankle. (21) Union was reported for 24 (86%) cases at an average of 10 weeks; complications included breakage of the stimulator cables in 2 patients and hardware failure in 1 patient. Five patients required additional surgery. Prospective controlled trials are needed to evaluate this procedure.

The 1992 TEC Assessment indicated that semi-invasive bone growth stimulators are no longer in wide use. (12)

Summary

There is evidence from randomized controlled trials (RCTs) and systematic reviews of clinical trials that noninvasive electrical stimulators improve fracture healing for patients with fracture non-union. This evidence is not from high-quality RCTs; however, and systematic reviews provide qualified support for this conclusion. Based on the available evidence and the lack of other options for patients with non-union, electrical stimulation may be considered medically necessary for the U.S. Food and Drug Administration (FDA)-approved indications of fracture nonunions or congenital pseudoarthroses in the appendicular skeleton when specific criteria are met.

There is insufficient evidence to permit conclusions regarding the efficacy of noninvasive electrical bone growth stimulation for treatment of stress fractures and a recent randomized trial found no benefit of electrical bone growth stimulation for fresh fractures. Use of noninvasive electrical bone growth stimulation for fresh fractures is considered experimental, investigational and/or unproven.

The literature for implantable bone stimulators of the appendicular skeleton consists of a small number of case series. In addition, no semi-invasive devices have FDA clearance or approval. The use of invasive or semi-invasive electrical bone growth stimulators is considered experimental, investigational and/or unproven.

Coding

Disclaimer for coding information on Medical Policies

Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each policy. They may not be all-inclusive.

The presence or absence of procedure, service, supply, device or diagnosis codes in a Medical Policy document has no relevance for determination of benefit coverage for members or reimbursement for providers. Only the written coverage position in a medical policy should be used for such determinations.

Benefit coverage determinations based on written Medical Policy coverage positions must include review of the member’s benefit contract or Summary Plan Description (SPD) for defined coverage vs. non-coverage, benefit exclusions, and benefit limitations such as dollar or duration caps.

ICD-9 Codes

78.90, 78.99, 99.86, 733.81, 733.82

ICD-10 Codes
Q74.0,  S32.2xxK – S32.9xxK;S42.00xK – S42.92xK; S49.00xK – S49.199K;S52.00xK – S52.92xN;S59.00xK – S59.299K; S62.00xK – S62.92xK; S72.00xK – S72.92xN; S79.00xK – S79.199K; S82.00xK – S82.92xN; S89.00xK – S89.399K; S92.00xK – S92.919K, M43.15-M43.17, M48.05-M48.07, M51.04-M51.9, 00HU0MZ, 00HU3MZ, 00HU4MZ, 00HV0MZ, 00HV3MZ, 00HV4MZ, 00WU0MZ, 0WU3MZ, 00WU4MZ, 00PV0MZ, 00PV3MZ, 00PV4MZ, 00WU0MZ, 00WU3MZ, 0WU4MZ, 00WV0MZ, 00WV3MZ, 00WV4MZ
Procedural Codes: 20974, 20975, E0747, E0748, E0749
References
  1. Blue Cross and Blue Shield Association Technology Evaluation Center (TEC). Electrical bone growth stimulation as an adjunct to spinal fusion surgery (invasive method). 1992 TEC Evaluations, pp. 324-51.
  2. Blue Cross and Blue Shield Association Technology Evaluation Center (TEC). Electrical bone growth stimulation in association with spinal fusion surgery (noninvasive method). 1993 TEC Evaluations, pp. 1-12.
  3. Kane WJ. Direct current electrical bone growth stimulation for spinal fusion. Spine (Phila Pa 1976) 1988; 13(3):363-5.
  4. Mooney V. A randomized double-blind prospective study of the efficacy of pulsed electromagnetic fields for interbody lumbar fusions. Spine (Phila Pa 1976) 1990; 15(7):708-12.
  5. Kucharzyk DW. A controlled prospective outcome study of implantable electrical stimulation with spinal instrumentation in a high-risk spinal fusion population. Spine (Phila Pa 1976) 1999; 24(5):465-8; discussion 69.
  6. Rogozinski A, Rogozinski C. Efficacy of implanted bone growth stimulation in instrumented lumbosacral spinal fusion. Spine (Phila Pa 1976) 1996; 21(21):2479-83.
  7. Andersen T, Christensen FB, Egund N et al. The effect of electrical stimulation on lumbar spinal fusion in older patients: a randomized, controlled, multi-center trial: part 2: fusion rates. Spine (Phila Pa 1976) 2009; 34(21):2248-53.
  8. Andersen T, Christensen FB, Ernst C et al. The effect of electrical stimulation on lumbar spinal fusion in older patients: a randomized, controlled, multi-center trial: part 1: functional outcome. Spine (Phila Pa 1976) 2009; 34(21):2241-7.
  9. Andersen T, Christensen FB, Langdahl BL et al. Fusion mass bone quality after uninstrumented spinal fusion in older patients. Eur Spine J 2010; 19(12):2200-8.
  10. Goodwin CB, Brighton CT, Guyer RD et al. A double-blind study of capacitively coupled electrical stimulation as an adjunct to lumbar spinal fusions. Spine (Phila Pa 1976) 1999; 24(13):1349-56; discussion 57.
  11. Linovitz RJ, Pathria M, Bernhardt M et al. Combined magnetic fields accelerate and increase spine fusion: a double-blind, randomized, placebo controlled study. Spine (Phila Pa 1976) 2002; 27(13):1383-9; discussion 89.
  12. Gaston MS, Simpson AH. Inhibition of fracture healing. J Bone Joint Surg Br 2007; 89(12):1553-60.
  13. Pountos I, Georgouli T, Blokhuis TJ et al. Pharmacological agents and impairment of fracture healing: what is the evidence? Injury 2008; 39(4):384-94.
  14. Foley KT, Mroz TE, Arnold PM et al. Randomized, prospective, and controlled clinical trial of pulsed electromagnetic field stimulation for cervical fusion. Spine J 2008; 8(3):436-42.
  15. U.S. Food and Drug Administration. Summary of Safety and Effectiveness Data: Cervical-Stim Model 505L Cervical Fusion System. 2004. Available online at: http://www.accessdata.fda.gov/cdrh_docs/pdf3/P030034b.pdf . Last accessed September 2011.
  16. Mackenzie D, Veninga FD. Reversal of delayed union of anterior cervical fusion treated with pulsed electromagnetic field stimulation: case report. South Med J 2004; 97(5):519-24.
  17. Resnick DK, Choudhri TF, Dailey AT et al. Guidelines for the performance of fusion procedures for degenerative disease of the lumbar spine. Part 17: bone growth stimulators and lumbar fusion. J Neurosurg Spine 2005; 2(6):737-40.
  18. Centers for Medicare and Medicaid Services. National Coverage Determination for Osteogenic Stimulators (150.2). Available online at: http://www.cms.hhs.gov/mcd/viewncd.asp?ncd_id=150.2&ncd_version=2&basket=ncd%3A150%2E2%3A2%3AOsteogenic+Stimulators. Last accessed August 2011. Bhandari M, Fong K, Sprague S et al. Variability in the definition and perceived causes of delayed unions and nonunions: a cross-sectional, multinational survey of orthopaedic surgeons. J Bone Joint Surg Am 2012; 94(15):e1091-6.
  19. Ahl T, Andersson G, Herberts P et al. Electrical treatment of non-united fractures. Acta Orthop Scand 1984; 55(6):585-8.
  20. Connolly JF. Selection, evaluation and indications for electrical stimulation of ununited fractures. Clin Orthop Relat Res 1981; (161):39-53.
  21. Connolly JF. Electrical treatment of nonunions. Its use and abuse in 100 consecutive fractures. Orthop Clin North Am 1984; 15(1):89-106.
  22. de Haas WG, Beaupre A, Cameron H et al. The Canadian experience with pulsed magnetic fields in the treatment of ununited tibial fractures. Clin Orthop Relat Res 1986; (208):55-8.
  23. Sharrard WJ, Sutcliffe ML, Robson MJ et al. The treatment of fibrous non-union of fractures by pulsing electromagnetic stimulation. J Bone Joint Surg Br 1982; 64(2):189-93.
  24. Griffin XL, Warner F, Costa M. The role of electromagnetic stimulation in the management of established non-union of long bone fractures: what is the evidence? Injury 2008; 39(4):419-29.
  25. Scott G, King JB. A prospective, double-blind trial of electrical capacitive coupling in the treatment of non-union of long bones. J Bone Joint Surg Am 1994; 76(6):820-6.
  26. Simonis RB, Parnell EJ, Ray PS et al. Electrical treatment of tibial non-union: a prospective, randomised, double-blind trial. Injury 2003; 34(5):357-62.
  27. Shi HF, Xiong J, Chen YX et al. Early application of pulsed electromagnetic field in the treatment of postoperative delayed union of long-bone fractures: a prospective randomized controlled study. BMC Musculoskelet Disord 2013; 14:35.
  28. Sharrard WJ. A double-blind trial of pulsed electromagnetic fields for delayed union of tibial fractures. J Bone Joint Surg Br 1990; 72(3):347-55.
  29. Blue Cross and Blue Shield Association Technology Evaluation Center (TEC). Electrical bone growth stimulation for delayed union or nonunion of fractures. TEC Assessment 1992:Volume 7:332-51.
  30. Griffin XL, Costa ML, Parsons N et al. Electromagnetic field stimulation for treating delayed union or non-union of long bone fractures in adults. Cochrane Database Syst Rev 2011; (4):CD008471.
  31. Barker AT, Dixon RA, Sharrard WJ et al. Pulsed magnetic field therapy for tibial non-union. Interim results of a double-blind trial. Lancet 1984; 1(8384):994-6.
  32. Borsalino G, Bagnacani M, Bettati E et al. Electrical stimulation of human femoral intertrochanteric osteotomies. Double-blind study. Clin Orthop Relat Res 1988; (237):256-63.
  33. Dhawan SK, Conti SF, Towers J et al. The effect of pulsed electromagnetic fields on hindfoot arthrodesis: a prospective study. J Foot Ankle Surg 2004; 43(2):93-6.
  34. Adie S, Harris IA, Naylor JM et al. Pulsed electromagnetic field stimulation for acute tibial shaft fractures: a multicenter, double-blind, randomized trial. J Bone Joint Surg Am 2011; 93(17):1569- 76.
  35. Hannemann PF, Gottgens KW, van Wely BJ et al. The clinical and radiological outcome of pulsed electromagnetic field treatment for acute scaphoid fractures: a randomised double-blind placebo-controlled multicentre trial. J Bone Joint Surg Br 2012; 94(10):1403-8.
  36. Beck BR, Matheson GO, Bergman G et al. Do capacitively coupled electric fields accelerate tibial stress fracture healing? A randomized controlled trial. Am J Sports Med 2008; 36(3):545-53.
  37. Petrisor B, Lau JT. Electrical bone stimulation: an overview and its use in high risk and Charcot foot and ankle reconstructions. Foot Ankle Clin 2005; 10(4):609-20, vii-viii.
  38. Lau JT, Stamatis ED, Myerson MS et al. Implantable direct-current bone stimulators in high-risk and revision foot and ankle surgery: a retrospective analysis with outcome assessment. Am J Orthop (Belle Mead NJ) 2007; 36(7):354-7.
  39. Electrical Stimulation of the Spine as an Adjunct to Spinal Fusion Procedures. Chicago, Illinois: Blue Cross Blue Shield Association Medical Policy Reference Manual (2013 October) Durable Medical Equipment 7.01.85.
  40. Electrical Bone Growth Stimulation of the Appendicular Skeleton. Chicago, Illinois: Blue Cross Blue Shield Association Medical Policy Reference Manual (2014 January) Durable Medical Equipment 7.01.07.
History
April 2012 Policy updated with literature review through July 2011; reference 11 added and references reordered; policy statements unchanged
November 2012 Policy updated with literature review through July 2012; references 1, 16 added and references reordered; arthrodesis added to investigational policy statement; definitions of fresh fractures, delayed union, and non-union added to policy guidelines.
November 2013 Policy formatting and language revised.  Combined the "Bone Growth Stimulators: Electrical Stimulation of the Appendicular Skeleton" and "Bone Growth Stimulators: Electrical Stimulation of the Spine as an Adjunct to Spinal Fusion Procedures" policies.  Policy title changed to "Electrical Bone Growth Stimulation (EBGS)".  Added "Treatment of failed joint fusion when a minimum of nine months has elapsed since the last surgery" to the non-spinal noninvasive medically necessary statement. 
February 2014 Document updated with literature review. The following was added as a medically necessary indication for non-spinal noninvasive EBGS: Delayed unions of fractures or failed arthrodesis at high-risk sites (i.e., open or segmental tibial fractures, carpal navicular fractures). In addition, stress fractures were added as an example of experimental, investigational and/or unproven indications.
BCBSMT Home
®Registered marks of the Blue Cross and Blue Shield Association, an association of independent Blue Cross and Blue Shield Plans. ®LIVE SMART. LIVE HEALTHY. is a registered mark of BCBSMT, an independent licensee of the Blue Cross and Blue Shield Association, serving the residents and businesses of Montana.
CPT codes, descriptions and material only are copyrighted by the American Medical Association. All Rights Reserved. No fee schedules, basic units, relative values or related listings are included in CPT. The AMA assumes no liability for the data contained herein. Applicable FARS/DFARS Restrictions Apply to Government Use. CPT only © American Medical Association.
Electrical Bone Growth Stimulation (EBGS)