Description:
Vertebral axial decompression applies traction to the vertebral column to reduce intradiscal pressure and, in doing so, potentially relieves low back pain associated with herniated lumbar discs or degenerative lumbar disc disease.

For individuals who have chronic lumbar pain who receive vertebral axial decompression, the evidence includes randomized controlled trials (RCTs). Relevant outcomes are symptoms, functional outcomes, quality of life, and treatment-related morbidity. Evidence for the efficacy of vertebral axial decompression on health outcomes is limited. Because a placebo effect may be expected with any treatment that has pain relief as the principal outcome, RCTs with sham controls and validated outcome measures are required. The only sham-controlled randomized trial published to date did not show a benefit of vertebral axial decompression compared with the control group. The evidence is insufficient to determine the effects of the technology on health outcomes.

Background
Vertebral axial decompression (also referred to as mechanized spinal distraction therapy) is used as traction therapy to treat chronic low back pain. Specific devices available are described in the Regulatory Status section. In general, during treatment, the patient wears a pelvic harness and lies prone on a specially equipped table. The table is slowly extended, and a distraction force is applied via the pelvic harness until the desired tension is reached, followed by a gradual decrease of the tension. The cyclic nature of the treatment allows the patient to withstand stronger distraction forces compared with static lumbar traction techniques. An individual session typically includes 15 cycles of tension, and 10 to 15 daily treatments may be administered.

Regulatory Status
Several devices used for vertebral axial decompression have received 510(k) marketing clearance from the U.S. Food and Drug Administration (FDA). According to labeled indications from the FDA, vertebral axial decompression may be used as a treatment modality for patients with incapacitating low back pain and for decompression of the intervertebral discs and facet joints.

Policy:
Vertebral axial decompression (e.g., by means of the VAX-D Table, the AxiomWorlWide DRX9000, the DRS System, The Alpha-Spina System, the Lordex Lumbar Spine System, The Saunder 3D Active Trac, NuChoice Medical Healthstar Elite Decompression Therapy, the Antalgic-Trak, the Cert Health Services SpineMED, or the Internal Disc Decompression (IDD) Therapy is considered INVESTIGATIONAL.

Policy Guidelines　
CPT code 97012 (application of a modality to one or more areas; traction, mechanical) may be used to describe vertebral axial decompression.

There is a specific HCPCS code: 

S9090 Vertebral axial decompression, per session.

Benefit Application
BlueCard/National Account Issues
State or federal mandates (e.g., FEP) may dictate that all FDA-approved devices may not be considered investigational, and thus these devices may be assessed only on the basis of their medical necessity.

Rationale
This evidence review was created in May 1997 and has been updated regularly with searches of the PubMed database. The most recent literature update was performed through Feb. 23, 2022.

Evidence reviews assess the clinical evidence to determine whether the use of a technology improves the net health outcome. Broadly defined, health outcomes are length of life, quality of life, and ability to function, including benefits and harms. Every clinical condition has specific outcomes that are important to patients and to managing the course of that condition. Validated outcome measures are necessary to ascertain whether a condition improves or worsens; and whether the magnitude of that change is clinically significant. The net health outcome is a balance of benefits and harms.

To assess whether the evidence is sufficient to draw conclusions about the net health outcome of a technology, 2 domains are examined: the relevance and the quality and credibility. To be relevant, studies must represent one or more intended clinical use of the technology in the intended population and compare an effective and appropriate alternative at a comparable intensity. For some conditions, the alternative will be supportive care or surveillance. The quality and credibility of the evidence depend on study design and conduct, minimizing bias and confounding that can generate incorrect findings. The randomized controlled trial (RCT) is preferred to assess efficacy; however, in some circumstances, nonrandomized studies may be adequate. Randomized controlled trials are rarely large enough or long enough to capture less common adverse events and long-term effects. Other types of studies can be used for these purposes and to assess generalizability to broader clinical populations and settings of clinical practice.

Vertebral Axial Decompression for Chronic Lumbar Pain
Clinical Context and Therapy Purpose
The purpose of vertebral axial decompression is to provide a treatment option that is an alternative to or an improvement on existing therapies, such as standard conservative therapy, in patients with chronic lumbar pain due to disc-related causes.

The question addressed in this evidence review is: Does the use of vertebral axial decompression improve the net health outcome in patients with chronic lumbar pain due to disc-related causes?

The following PICO was used to select literature to inform this review.

Populations
The relevant population of interest are individuals with chronic lumbar pain due to disc-related causes.

Interventions
The therapy being considered is vertebral axial decompression.

Vertebral axial decompression applies traction to the vertebral column to reduce intradiscal pressure, and in doing so, potentially relieves low back pain associated with herniated lumbar discs or degenerative lumbar disc disease.

Comparators
The following practice is currently being used to treat chronic lumbar pain due to disc-related causes: standard conservative therapy.

Conservative management includes nonsteroidal anti-inflammatory medications, back braces, and physical therapy; other nonsurgical treatments could include muscle relaxants, narcotic pain medications, or epidural steroid injections.¹

Outcomes
The general outcomes of interest are symptoms, functional outcomes, quality of life, and treatment-related morbidity.

Follow-up for patients receiving vertebral axial decompression would ideally be 6 months or longer.

Study Selection Criteria
Methodologically credible studies were selected using the following principles:  

• To assess efficacy outcomes, comparative controlled prospective trials were sought, with a preference for RCTs.

• In the absence of such trials, comparative observational studies were sought, with a preference for prospective studies.

• To assess long-term outcomes and adverse events, single-arm studies that capture longer periods of follow-up and/or larger populations were sought.

• Consistent with a 'best available evidence approach,' within each category of study design, studies with larger sample sizes and longer durations were sought.

• Studies with duplicative or overlapping populations were excluded.

Review of Evidence
Systematic Reviews
Vanti et al. (2021) published a systematic review with meta-analysis that evaluated the efficacy of mechanical traction with or without other conservative treatments on pain and disability in adults with lumbar radiculopathy. A list of studies included in the meta-analysis is found in Table 1. The characteristics of trials included in the systematic review and results of the meta-analysis are summarized in Tables 2 and 3, respectively. Of note, only analyses that included more than 1 RCT are summarized in Table 3. Briefly, results demonstrated that supine mechanical traction added to physical therapy had significant effects on pain and disability, whereas, prone mechanical traction added to physical therapy did not demonstrate these effects.

Table 1. Summary of Trials/Studies Included in SR & M-A  

M-A: meta-analysis; SR: systematic review.

Table 2. SR & M-A Characteristics  

M-A: meta-analysis; RCT: randomized controlled trial; SR: systematic review.

Table 3. SR & M-A Results  

M-A: meta-analysis; SR: systematic review.
CI: confidence interval; NNT: number needed to treat.

Randomized Controlled Trials
Results from 2 RCTs not included in the Vanti systematic review are as follows.

Schimmel et al. (2009) published results from a randomized sham-controlled trial of intervertebral axial decompression.³ Sixty subjects with chronic symptomatic lumbar disc degeneration or bulging disc with no radicular pain and no prior surgical treatment (dynamic stabilization, fusion, or disc replacement) were randomized to a graded activity program with an Accu-SPINA device (20 traction sessions during 6 weeks, reaching > 50% of body weight) or to a graded activity program with a non-therapeutic level of traction (< 10% body weight). In addition to traction, the device provided massage, heat, relaxing blue light, and music during the treatment sessions. While the physiotherapist who conducted the lumbar traction was unblinded, neither patients nor evaluators were informed about the intervention received until after the 14-week follow-up assessment and the intention-to-treat analysis was performed (93% of subjects completed follow-up). Both groups showed improvements in validated outcome measures (visual analog scale scores for back and leg pain, Oswestry Disability Index, 36-Item Short-Form Health Survey) but there were no significant differences between treatment groups. For example, visual analog scale scores for low back pain (the primary outcome) decreased from 61 to 32 in the active group and from 53 to 36 in the sham group. Evidence from this RCT did not support improvements in health outcomes with vertebral axial decompression.

Isner-Horobeti et al. (2016) reported on a preliminary double-blind RCT comparing high-force traction (50% body weight; n = 8) with low-force traction (10% body weight; n = 9) for individuals with acute low back pain and radiculopathy due to lumbar disc herniation.⁴ Patients were enrolled from a French emergency department. Inclusion criteria were lumbar sciatica of fewer than 6 weeks in duration, secondary to disc herniation based on clinical exam, confirmed by lumbar tomodensitometry. Patients with clinical neurologic deficits, sciatica due to something other than disc herniation, or abnormalities on tomodensitometry were excluded. For the trial’s primary outcome (reduction in radicular pain measured by a 100-mm visual analog scale), both groups demonstrated significant improvements from baseline to day 28. However, there was no significant interaction effect (group-by-time) regarding pain reduction. Similar findings were seen for lumbo-pelvic-hip mobility (measured by the finger-toe test) and nerve root compression (measured by the straight leg raise test). Overall, this trial suggested some rapid short-term within-subject improvements with high-dose lumbar traction. Although lumbar traction was not compared with a placebo, the comparison with low-level traction may approximate a placebo, similar to the Schimmel et al (2009) RCT, which used traction at 10% body weight traction as a placebo. The lack of significant interaction term suggests the active intervention is not associated with improved outcomes. However, the trial’s small size might mean that it was underpowered.

Table 4. Summary of Key RCT Characteristics  

NR: not reported; RCT: randomized controlled trial.

Table 5. Summary of Key RCT Results 

CI: confidence interval; MD: mean difference; RCT: randomized controlled trial; VAS: visual analogue scale.
¹ Defined as at least a 50% improvement in the patient’s pain and an improvement in their disability rating.

The purpose of the study limitations tables (see Tables 6 and 7) is to display notable limitations identified in each study.

Table 6. Study Relevance Limitations  

The study limitations stated in this table are those notable in the current review; this is not a comprehensive gaps assessment.
^a Population key: 1. Intended use population unclear; 2. Study population is unclear; 3. Study population not representative of intended use; 4, Enrolled populations do not reflect relevant diversity; 5. Other.
^b Intervention key: 1. Not clearly defined; 2. Version used unclear; 3. Delivery not similar intensity as comparator; 4. Not the intervention of interest (e.g., proposed as an adjunct but not tested as such); 5: Other.
^c Comparator key: 1. Not clearly defined; 2. Not standard or optimal; 3. Delivery not similar intensity as intervention; 4. Not delivered effectively; 5. Other.
^d Outcomes key: 1. Key health outcomes not addressed; 2. Physiologic measures, not validated surrogates; 3. Incomplete reporting of harms; 4. Not establish and validated measurements; 5. Clinically significant difference not prespecified; 6. Clinically significant difference not supported; 7. Other.
^e Follow-Up key: 1. Not sufficient duration for benefit; 2. Not sufficient duration for harms; 3. Other.

Table 7. Study Design and Conduct Limitations  

The study limitations stated in this table are those notable in the current review; this is not a comprehensive gaps assessment.
^a Allocation key: 1. Participants not randomly allocated; 2. Allocation not concealed; 3. Allocation concealment unclear; 4. Inadequate control for selection bias; 5. Other.
^b Blinding key: 1. Participants or study staff not blinded; 2. Outcome assessors not blinded; 3. Outcome assessed by treating physician; 4. Other.
^c Selective Reporting key: 1. Not registered; 2. Evidence of selective reporting; 3. Evidence of selective publication; 4. Other.
^d Data Completeness key: 1. High loss to follow-up or missing data; 2. Inadequate handling of missing data; 3. High number of crossovers; 4. Inadequate handling of crossovers; 5. Inappropriate exclusions; 6. Not intent to treat analysis (per protocol for noninferiority trials); 7. Other.
^e Power key: 1. Power calculations not reported; 2. Power not calculated for primary outcome; 3. Power not based on clinically important difference; 4. Other.
^f Statistical key: 1. Analysis is not appropriate for outcome type: (a) continuous; (b) binary; (c) time to event; 2. Analysis is not appropriate for multiple observations per patient; 3. Confidence intervals and/or p values not reported; 4. Comparative treatment effects not calculated; 5. Other.

Summary of Evidence
For individuals with chronic lumbar pain who receive vertebral axial decompression, the evidence includes a systematic review and RCTs. Relevant outcomes are symptoms, functional outcomes, quality of life, and treatment-related morbidity. Evidence for the efficacy of vertebral axial decompression on health outcomes is limited. Because a placebo effect may be expected with any treatment that has pain relief as the principal outcome, RCTs with sham controls and validated outcome measures are required. The only sham-controlled randomized trial published to date did not show a benefit of vertebral axial decompression compared with the control group. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

The purpose of the following information is to provide reference material. Inclusion does not imply endorsement or alignment with the evidence review conclusions.

Practice Guidelines and Position Statements
Guidelines or position statements will be considered for inclusion in ‘Supplemental Information’ if they were issued by, or jointly by, a U.S. professional society, an international society with U.S. representation, or National Institute for Health and Care Excellence (NICE). Priority will be given to guidelines that are informed by a systematic review, include strength of evidence ratings, and include a description of management of conflict of interest.

No guidelines or statements were identified.

U.S. Preventive Services Task Force Recommendations
Not applicable

Ongoing and Unpublished Clinical Trials
A search of ClinicalTrials.gov in February 2022 did not identify any ongoing or unpublished trials that would likely influence this review.

References: 

1. Peloza J. Non-Surgical Treatments for Lower Back Pain. Spine-health. https://www.spine-health.com/conditions/lower-back-pain/non-surgical-treatments-lower-back-pain. Updated April 20, 2017. Accessed February 23, 2022.
2. Vanti C, Turone L, Panizzolo A, et al. Vertical traction for lumbar radiculopathy: a systematic review. Arch Physiother. Mar 15 2021; 11(1): 7. PMID 33715638
3. Schimmel JJ, de Kleuver M, Horsting PP, et al. No effect of traction in patients with low back pain: a single centre, single blind, randomized controlled trial of Intervertebral Differential Dynamics Therapy. Eur Spine J. Dec 2009; 18(12): 1843-50. PMID 19484433
4. Isner-Horobeti ME, Dufour SP, Schaeffer M, et al. High-Force Versus Low-Force Lumbar Traction in Acute Lumbar Sciatica Due to Disc Herniation: A Preliminary Randomized Trial. J Manipulative Physiol Ther. Nov 2016; 39(9): 645-654. PMID 27838140
5. Centers for Medicare & Medicaid Services. National Coverage Decision (NCD) for Vertebral Axial Decompression (VAX-D) (160.16). 1997; https://www.cms.gov/medicare-coverage-database/details/ncd-details.aspx?ncdid=124&KeyWord=vertebral%20axial%20decompress&KeyWordLookUp=Title&KeyWordSearchType=Exact&bc=CAAAAAAAAAAA. Accessed February 23, 2022.

Coding Section

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. 

This medical policy was developed through consideration of peer-reviewed medical literature generally recognized by the relevant medical community, U.S. FDA approval status, nationally accepted standards of medical practice and accepted standards of medical practice in this community, Blue Cross Blue Shield Association technology assessment program (TEC) and other nonaffiliated technology evaluation centers, reference to federal regulations, other plan medical policies, and accredited national guidelines.

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