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Electrical Stimulation of the Spine as an Adjunct to Spinal Fusion Procedures

Policy Number: MP-524

Latest Review Date: April 2021

Category: DME                                                                     

Policy Grade: B

POLICY:

Non-invasive and invasive electrical bone growth stimulation (E0748, E0749) may be considered medically necessary as an adjunct to lumbar spinal fusion surgery for patients at high risk of pseudarthrosis, including those with one or more of the following conditions:

  • One or more previously failed  spinal fusion (s) (defined as a spinal fusion that has not healed at a minimum of 6 months after the original surgery as evidenced by serial x-rays over a course of 3 months);
  • Grade III or worse spondylolisthesis;
  • Fusion to be performed at more than one level;
  • Current smoking habit;
  • Diabetes;
  • End Stage Renal disease;
  • Alcoholism; current or recent history of alcoholism;
  • Osteoporosis (significant, as demonstrated by imaging studies);
  • Steroid use.

Semi-invasive electrical stimulation is considered investigational as an adjunct to lumbar fusion surgery and for failed lumbar fusion.

Invasive, semi-invasive, and noninvasive electrical stimulation is considered investigational as an adjunct to cervical fusion surgery and for failed cervical spine fusion.

DESCRIPTION OF PROCEDURE OR SERVICE:

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.

Electrical Bone Growth Stimulators

Electrical and electromagnetic fields can be generated and applied to bones through surgical, noninvasive, and semi-invasive methods.

Invasive Stimulators

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 Stimulators

Noninvasive electrical bone growth stimulators generate a weak electrical current within the target site using either 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 into a back brace or directly onto the skin and are worn for 6 to 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 Stimulators

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.

KEY POINTS:

The most recent literature review was updated through March 6, 2021 with search of MEDLINE database.

SUMMARY OF EVIDENCE:

For individuals who are at high risk of lumbar spinal fusion failure surgery who receive invasive or noninvasive electrical bone growth stimulation, the evidence includes systematic reviews, a TEC Assessment, and randomized controlled trials (RCTs). Relevant outcomes are symptoms, change in disease status, and functional outcomes. Results from these trials have indicated that, in patients with risk factors for failed fusion, either invasive or noninvasive electrical bone stimulation increases the fusion rate. The evidence is sufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who have failed lumbar spinal fusion surgery who receive noninvasive electrical bone growth stimulation, the evidence includes a TEC Assessment and studies with patients serving as their own controls. Relevant outcomes are symptoms, change in disease status, and functional outcomes. Data have shown that noninvasive electrical stimulation improves fusion rates in this population. The evidence is sufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who are undergoing cervical spinal fusion surgery or have failed cervical spine fusion who receive invasive or noninvasive electrical bone growth stimulation, the evidence includes an RCT. Relevant outcomes are symptoms, change in disease status, and functional outcomes. The only controlled trial published to date had methodologic limitations, and the efficacy of electrical stimulation in the cervical spine has not been established. An open-label multicenter cohort study provided evidence to demonstrate that patients at high risk for arthrodesis following anterior cervical discectomy and fusion procedures reported statistically significant improvements in fusion rates with pulsed electromagnetic field stimulation. However, limitations in the study design, including use of a historical control group, lack of blinding, and no restrictions on surgical methods used by surgeons, preclude definitive assessments of treatment efficacy. The evidence is insufficient to determine that the technology results in an improvement In the net health outcome.

Practice Guidelines and Position Statements:

North American Spine Society

In 2016, the North American Spine Society (NASS) issued a coverage recommendation for electrical bone growth stimulators.

  1. “For augmentation of spinal fusion in any and all regions of the spine including occipital-cervical, cervical, cervicothoracic, thoracic, thoracolumbar, lumbar and lumbosacral spinal regions in patients at high-risk for the development of pseudarthrosis (i.e., nonunion) who exhibit one or more of the following:
    • Are undergoing spinal fusion of two or more motion segments (3 vertebrae)
    • Are undergoing a revision spinal fusion (e.g., repeat surgery for a previously unhealed fusion attempt)
    • Are smokers who cannot stop smoking in preparation for fusion due to the nature of the underlying condition (e.g., acute traumatic fracture)
    • Exhibit one or more of the following comorbidities when undergoing primary lumbar fusion:
      • Diabetes
      • Inflammatory arthritis (e.g., rheumatoid arthritis) that has required long-term corticosteroid therapy
      • Immunocompromised (e.g., undergoing chemotherapy and radiation therapy to the spine, hypogammaglobinemia, granulocytopenia, acquired immune deficiency syndrome, chronic granulomatous disease)
      • Systemic vascular disease
      • Osteopenia or osteoporosis
  2. In the lumbar spine, the following forms of electrical stimulation are indicated in high-risk patients with the specific techniques outlined. In all other regions of the spine, coverage for the same indications is recommended although there is less supporting evidence.
  • DCS [direct current stimulation: electrodes implanted within or very close to the location of the desired fusion] and CCS [capacitance coupling stimulation; 2 electrodes placed on the skin over the fusion site] for posterolateral fusion using autograft and extender
  • PEMFS [pulsed electromagnetic field stimulation: coils that produce a time-varying magnetic field around the area of the desired fusion] for lumbar interbody fusion.”

American Association of Neurological Surgeons and Congress of Neurological Surgeons

Updated 2014 guidelines from the American Association of Neurological Surgeons (AANS) and the Congress of Neurological Surgeons (CNS) have indicated that there was no evidence published after their 2005 guidelines that conflict with the previous recommendations on bone growth stimulation.

Based on a single level II study from 2009, the routine use of direct current stimulation (DCS) in patients older than age 60 years was not recommended. Use of DCS was recommended as an option for patients younger than 60 years of age, based on level III and IV studies showing a positive impact on fusion rate. However, concerns about the level III study were that it was a poorly designed and poorly conducted cohort study consisting of an exceedingly small heterogeneous population of patients, and the overall recommendation was level C. There was insufficient evidence to recommend for or against the use of pulsed electromagnetic field stimulation (PEMFS) as a treatment alternative to revision surgery in patients presenting with pseudoarthrosis following posterolateral lumbar fusion (PLF; single-level IV study). No additional studies investigating the efficacy of capacitive coupled electrical stimulation were identified.

The 2 medical associations also issued guidelines in 2005 that stated there was class II and III evidence (nonrandomized comparative trials and case series):

“…to support the use of direct current stimulation or [capacitive coupled stimulation] for enhancing fusion rates in high-risk patients undergoing lumbar PLF. 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 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 four-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.”

U.S. Preventive Services Task Force Recommendations

Not applicable.

KEY WORDS:

Bone Growth Stimulation, Spine, Electrical Bone Growth Stimulation, Electrical Stimulation, Spinal Fusion, Cervical-Stim, EBI Bone Healing System, OsteoStim, SpinalPak, SpinaLogic Bone Growth Stimulator, Spinal-Stim Lite

APPROVED BY GOVERNING BODIES:

The following implantable device was approved by the U.S. Food and Drug Administration (FDA) through the premarket approval process:

  • The OsteoStim® (Electro-Biology) 1986, which may also be marketed under the trade name SPF (Biomet).

The following noninvasive bone growth stimulators were approved by FDA through the premarket approval process:

  • In 1999, the SpinalPak® bone growth stimulator system (Biolectron, a subsidiary of Electro-Biology, Parsippany, NJ), a capacitive coupling system, was approved by FDA through the premarket approval process for use as an adjunct to primary lumbar spinal fusion at 1 or 2 levels.
  • In 1979, the EBI Bone Healing System® (Biolectron, a subsidiary of Electro-Biology, Parsippany, NJ), a pulsed electromagnetic field system, approved by FDA through the premarket approval process for nonunions, failed fusions, and congenital pseudoarthrosis. The device is secured with a belt around the waist.
  • In 1994, the SpinaLogic Bone Growth Stimulator® (Regentek, a division of dj Orthopedics [formerly OrthoLogic, Tempe, AZ]) was approved by FDA through the premarket approval process as a combined magnetic field portable device. This device is secured with a belt around the waist.
  • In 1996, the Spinal-Stim Lite ® (Orthofix, Richardson, TX) was approved by FDA through the premarket approval process 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.
  • In 2004, the Stim® (Orthofix, Richardson, TX), a pulsed electromagnetic field system, was approved by FDA through the premarket approval process as an adjunct to cervical fusion surgery in patients at high risk for nonfusion.

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

BENEFIT APPLICATION:

Coverage is subject to member’s specific benefits. Group specific policy will supersede this policy when applicable.

ITS: Home Policy provisions apply.

FEP: Special benefit consideration may apply. Refer to member’s benefit plan. FEP does not consider investigational if FDA approved and will be reviewed for medical necessity.

CURRENT CODING:

CPT Codes:

20974

Electrical stimulation to aid bone healing; non-invasive (non-operative)

20975

Electrical stimulation to aid bone healing; invasive (operative)

HCPCS Codes:

E0748

Osteogenesis stimulator, electrical, noninvasive, spinal application

E0749

Osteogenesis stimulator, electrical (surgically implanted)

REFERENCES:

  1. Akai M, Kawashima N, Kimura T, et al. Electrical stimulation as an adjunct to spinal fusion: a meta-analysis of controlled clinical trials. Bioelectromagnetics 2002; 23(7):496-504.
  2. Akhter S., Qureshi A.R., Aleem I. et al. Efficacy of Electrical Stimulation for Spinal Fusion: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Sci Rep 10. 4568 (2020).
  3. 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.
  4. 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.
  5. 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.
  6. 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.
  7. 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.
  8. Coric D, Bullard DE, Patel VV, et al. Pulsed electromagnetic field stimulation may improve fusion rates in cervical arthrodesis in high-risk populations. Bone Joint Res. Feb 2018; 7(2):124-130.
  9. Foley KT, Mroz TE, Arnold PM, et al. Randomized, prospective, and controlled clinical trial of pulsed electromagnetic field stimulation for cervical fusion. Spin J, May-Jun 2008; 8(3): 436-442.
  10. Gaston MS, Simpson AH. Inhibition of fracture healing. J Bone Joint Surg Br 2007; 89(12):1553-60.
  11. 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 1999; 24(13):1349-57.
  12. HodgesSD, Eck JC and Humphreys SC. Use of electrical bone stimulation in spinal fusion. J Am Acad Orthop Surg 2003; 11(2):81-8.
  13. IOM (Institute of Medicine). 2011. Clinical Practice Guidelines We Can Trust. Washington, DC: The National Academies Press.
  14. Kaiser MG, Eck JC, Groff MW, et al. Guideline update for the performance of fusion procedures for degenerative disease of the lumbar spine. Part 17: bone growth stimulators as an adjunct for lumbar fusion. J Neurosurg Spine. Jul 2014; 21(1):133-139.
  15. Kane WJ. Direct current electrical bone growth stimulation for spinal fusion. Spine 1988; 13(3):363-5.
  16. Kucharzyk DW. A controlled prospective outcome study of implantable electrical stimulation with spinal instrumentation in a high-risk spinal fusion population. Spine 1999; 24(5):465-9.
  17. Linovitz RJ, Pathria M, Bernhardt M, et al. Combined magnetic fields accelerate and increase spine fusion: a double-blind, randomized, placebo controlled study. Spine 2002; 27(13):1383-9.
  18. 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.
  19. Mooney V. A randomized double-blind prospective study of the efficacy of pulsed electromagnetic fields for interbody lumbar fusions. Spine 1990; 15(7):708-12.
  20. North American Spine Society (NASS). NASS Coverage Policy Recommendations: Electrical Stimulation for Bone Healing. 2016; //www.spine.org/PolicyPractice/CoverageRecommendations/AboutCoverageRecommendations.aspx. Accessed April 7, 2017.
  21. Park P, Lau D, Brodt ED, et al. Electrical stimulation to enhance spinal fusion: a systematic review. Evid Based Spine Care J. Oct 2014; 5(2):87-94.
  22. 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.
  23. Reznick 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.
  24. Rogozinksi A and Rogozinski C. Efficacy of implanted bone growth stimulation in instrumented lumbosacral spinal fusion. Spine 1996; 21(21):2479-83.
  25. U.S. Food and Drug Administration. Summary of Safety and Effectiveness Data: Cervical-Stim Model 505L Cervical Fusion System. 2004. Available online at: www.accessdata.fda.gov/cdrh_docs/pdf3/P030034b.pdf.

POLICY HISTORY:

Medical Policy Group, October 2008 (4)

Medical Policy Administration Committee, November 2008

Available for comment November 20, 2008-January 5, 2009

Medical Policy Group, February 2009 (4)

Medical Policy Administration Committee, March 2009

Available for comment February 27-April 13, 2009

Medical Policy Group, October 2009 (1)

Medical Policy Administration Committee, October 2009

Available for comment October 20-December 3, 2009

Medical Policy Group, November 2009 (1)

Medical Policy Administration Committee, December 2009

Available for comment December 4, 2009-January 19, 2010

Medical Policy Group, February 2010 (1)

Medical Policy Administration Committee, April 2010

Available for comment April 7-May 21, 2010

Medical Policy Group, February 2010; Regular update (1)

Medical Policy Group, November 2011 (1): Electrical bone growth stimulators separated from policy #331; Update to Key Points and References; no change in policy statement

Medical Policy Administration Committee, January 2012

Available for comment January 11 – February 27, 2012

Medical Policy Panel, October 2012

Medical Policy Group, March 2013 (1): Electrical Stimulation of the Spine separated from policy #082; Update to Approved by Governing Bodies; updated literature search; no change in policy statement

Medical Policy Panel, October 2013

Medical Policy Group, October 2013 (1): Updated literature search; no change to policy statement

Medical Policy Panel, October 2014

Medical Policy Group, October 2014 (5): Updated Practice Guidelines and Position Statements and added Reference to support; no change to policy statement

Medical Policy Panel April 2016

Medical Policy Group, April 2016 (6): Updated Key Points and References; no change to policy statement.

Medical Policy Panel, May 2017

Medical Policy Group, May 2017 (6): Updates to Key Points, Practice Guidelines and References. Added “lumbar” to policy statement for clarification.

Medical Policy Panel, April 2018

Medical Policy Group, May 2018 (6): Updates to Key Points and References.

Medical Policy Panel, April 2019

Medical Policy Group, April 2019 (6): Updates to Description and Key Points.

Medical Policy Panel, April 2020

Medical Policy Group, April 2020 (6) Updates to Key Points and References. No change to policy intent.

Medical Policy Panel, April 2021

Medical Policy Panel, April 2021 (6): Updates to Key Points, Practice Guidelines and References. Policy statement updated to remove “not medically necessary,” no change to policy intent.

This medical policy is not an authorization, certification, explanation of benefits, or a contract. Eligibility and benefits are determined on a case-by-case basis according to the terms of the member’s plan in effect as of the date services are rendered. All medical policies are based on (i) research of current medical literature and (ii) review of common medical practices in the treatment and diagnosis of disease as of the date hereof. Physicians and other providers are solely responsible for all aspects of medical care and treatment, including the type, quality, and levels of care and treatment.

This policy is intended to be used for adjudication of claims (including pre-admission certification, pre-determinations, and pre-procedure review) in Blue Cross and Blue Shield’s administration of plan contracts.

The plan does not approve or deny procedures, services, testing, or equipment for our members. Our decisions concern coverage only. The decision of whether or not to have a certain test, treatment or procedure is one made between the physician and his/her patient. The plan administers benefits based on the member’s contract and corporate medical policies. Physicians should always exercise their best medical judgment in providing the care they feel is most appropriate for their patients. Needed care should not be delayed or refused because of a coverage determination.

As a general rule, benefits are payable under health plans only in cases of medical necessity and only if services or supplies are not investigational, provided the customer group contracts have such coverage.

The following Association Technology Evaluation Criteria must be met for a service/supply to be considered for coverage:

1. The technology must have final approval from the appropriate government regulatory bodies;

2. The scientific evidence must permit conclusions concerning the effect of the technology on health outcomes;

3. The technology must improve the net health outcome;

4. The technology must be as beneficial as any established alternatives;

5. The improvement must be attainable outside the investigational setting.

Medical Necessity means that health care services (e.g., procedures, treatments, supplies, devices, equipment, facilities or drugs) that a physician, exercising prudent clinical judgment, would provide to a patient for the purpose of preventing, evaluating, diagnosing or treating an illness, injury or disease or its symptoms, and that are:

1. In accordance with generally accepted standards of medical practice; and

2. Clinically appropriate in terms of type, frequency, extent, site and duration and considered effective for the patient’s illness, injury or disease; and

3. Not primarily for the convenience of the patient, physician or other health care provider; and

4. Not more costly than an alternative service or sequence of services at least as likely to produce equivalent therapeutic or diagnostic results as to the diagnosis or treatment of that patient’s illness, injury or disease.