Response to Comments: Trigger Point Injections (TPI)

The American Society of Interventional Pain Physicians (ASIPP) and Society of Interventional Pain Management Surgery Centers Inc. (SIPMS) submitted a joint comment letter. They request that steroids be added to the allowed injectants. Literature was included with their comments (applying to multiple aspects of the policy, but there was no literature to support this request.^1-5

Several of the subject matter experts’ states there is potential harm and not sufficient evidence for steroids to be included in TPI. There are studies that suggest the addition of corticosteroid does not reduce pain more than TPI with local anesthesia alone.⁶

ASIPP/SIPMS comments “since the reimbursement is based on multiple muscle groups and limited to 2 or more, we request that this limitation be revised and permit multiple anatomic regions during the same session. This will avoid multiple visits for the patients and provide cost savings. If they are performed separately, it will be more expensive and requires additional physician and staff time.”

A comment was received expressing concern with the limitation of multiple blocks during the same session. The commenter stated that they think it is very reasonable for same anatomic area, but requested allowing different anatomical areas with different issues to be injected in the same session. The comment is due to concerns for patient convenience, transportation issues, and increase cost to patient for multiple sessions. There was no supporting literature submitted.

A provider states that the myofascial system occurs in chains or meridians, therefore it is reasonable to inject multiple muscle groups along a chain which is their practice.⁷

Of the submitted literature from ASIPP, 3 articles were added to the LCD.^1-3 One was not added since it was on dry needling and TENS for myofascial pain rather than TPI.⁴ One was not added since it was a case report which was not included in the evidence review due to very low quality.⁵

One article was submitted which describes myofascial system runs in chains or meridians. The article does not explore if trigger points due to myofascial pain also runs in this pattern. Most trigger points are isolated within the muscle chains.⁷

While we appreciate the concerns expressed, there is not evidence submitted for treatment of multiple anatomic areas within the same session. While we understand a single patient may have multiple pain sources, if multiple injections are given in the same session, it obscures the ability to determine which treatment was effective for pain relief. The policy requires at least a 50% improvement in pain and/or function from the TPI. If other injections are performed simultaneously that cannot be adequately accessed.

• ASIPP/SIPMS comments on the limitation of three sessions in a rolling 12 months. They state “The present limitations are 3 trigger point injection sessions per rolling 12 months. This may be appropriate to change to 4 sessions per region, and if appropriate, if the first procedure does not provide 6 weeks of relief, a repeat procedure may be performed.”

• A commenter who served as a subject matter expert on this topic states that there is literature to support more than 3 sessions in a rolling 12 months. They state: “American Society of Interventional Pain Physicians Practice Guidelines (Interventional Techniques in the Management of Chronic Pain: Part 2.0), it is stated that in the diagnostic phase, injections should be at least 1 week apart, not to exceed 4 in one year. In the therapeutic phase, injections should be at least 2 months apart, and not exceed 6 in one year.”⁸ Therefore, in light of the guidelines in the literature, I propose either removing the limitation section or changing the limitation section to “No more than six (6) TPI sessions will be reimbursed per rolling 12 months. The potential economic hazard to third-party payors (if the limit were to be increased to a number greater than three TPI sessions per rolling 12 months) is likely to be quite low. At the multi-jurisdictional contractor advisory committee meeting in April, the panel of subject matter experts agreed that it is rare for these injections to be performed more frequently than every 3 months. This is cited in the “Summary of Evidence” section, “Trigger Point Injections” subsection, paragraph 4. This suggests that it would be uncommon to incur the marginal expense of a patient receiving a fourth TPI session in a 12-month period, regardless of limitations.”

• A commenter objects to the limitation of 3 sessions per rolling year. They explain if pain relief is expected to last about 6 weeks and then more sessions would be necessary for repeat injections. They state this is necessary for functional restoration. There was no supporting literature submitted.

• A provider states that needling therapies can be useful options for recalcitrant myofascial pain which is difficult to treat. Acupuncture and dry needling are not covered by most insurance therefore they use trigger point injections as “poor man’s” acupuncture. He provides a clinical example of a patient who does well with injections every 6-8 weeks. He states lack of literature to support the ideal frequency of trigger point injections and shares 2 review papers.^9,10  

ASIPP recommends weekly injections during the diagnostic phase which was limited to no more than 4 times per year and at least 2 months apart thereafter to a maximum of 6/12 months.⁸ It is not defined what constitutes diagnostic and therapeutic phases and when one ends and the other begins in the paper. As SMEs have indicated a single TPI can be useful in diagnosis to distinguish myofascial pain from other etiologies. This was allowed for the initial injection. Therefore, after a diagnostic injection, any subsequent injections are considered therapeutic. There is a paucity of evidence on long term use of TPI and most literature is limited to 2 to 8 weeks. Use of TPI beyond 6 months is not supported in current literature. Therefore, even with an initial diagnostic injection there is lack of evidence that more than 3 injections are indicated based on current literature.

The submitted systematic review was included in the LCD.⁹ The other submitted paper was a review paper which was not added to the evidence review section within the LCD since it was not original research. Within this review¹⁰ the author discusses the hypothesis of TPI effectiveness coming from activation and deactivation of the muscle which can be achieved with dry needling, acupuncture, trigger point injections of local anesthetic, steroids or Botox. They report mixed results but overall seem to result in pain relief. They acknowledge the lack of RCT and that most studies have small sample sizes resulting in uncertainty about the validity of findings. They support an approach that targets correct diagnosis and addressing underlying pathophysiology of perpetuating factors to achieve sustained relief. There is no evidence within this paper to support more frequent TPIs. 

A commenter states opposition to the definitions of dry needling and acupuncture in the policy. She states opposition to “rebranding” of acupuncture stating the definitions are intended to mislead the public. A newspaper file and article were provided.

Thank you for your comment. The attached articles were reviewed. They do not provide alternative definitions for dry needling or acupuncture. These address acupuncture laws and scope of practice. This policy is on trigger point injections and does not address acupuncture which is addressed in NCD 30.3.¹¹

A comment requests a change to conservative treatment from requiring part of an active rehabilitation, home exercise or functional restoration program to have tried and failed on any conservative treatment. He provides an example of a patient in acute pain whose pain was improved with a trigger point injection. He explains that sometimes conservative treatment does not work, or the patient is not interested because they are in pain. He recommends removal of any requirement for conservative treatment. 

Thank you for your comments. No supporting evidence was submitted for this recommendation. The LCD section Conservative Management reviews the supporting literature and rationale for conservative care.

The same commenter objects to the requirement for 6 weeks duration before TPI is repeated in the same location. He recommends being able to repeat the injection at one week and continue treatment until pain is completely resolved or significant improvement is achieved, allowing the patient to be fully functional at home or work. He argues that lidocaine is safe and given locally so there is no need to wait 6 weeks. He also states that sometimes the patients need 5-7 treatments or more to achieve results. He opposes any restrictions in the duration between injections or the number of injections allowed. He argues that there are little to no side effects related to TPIs and therefore concludes there should be no limitations. He provides a review paper that states “little to no side effects”. He submitted supporting literature.^2,12-14

Literature was submitted regarding frequency and duration between injections. A “frequency of injection” section has been added to the LCD with analysis of the submitted literature in response to these comments.

A systematic review was submitted to demonstrate the safety of TPI with local anesthesia.¹⁴ The commenter felt this provides evidence that it is safe and therefore no limitations apply. While safety is reassuring for a service to be reasonable and necessary it must also be effective which was not demonstrated in this review.

A review paper was also submitted.¹⁵ Review papers are excluded from the evidence analysis if they are not systematic reviews nor represent new literature. This was included as the commenter felt this was supportive evidence for more frequent injections. “Re-evaluation of the injected areas may be necessary, but reinjection of the trigger points is not recommended until the post-injection soreness resolves, usually after three to four days.” This is not supported by literature.

Two papers were submitted, Raeissadat et al. ¹² and Korkmaz et al. ². In both papers, assessments were made at baseline and post-treatment however no assessments were measured between the injections administered weekly to determine timing of improvement in score from baseline. Due to the lack of measurement of pain from baseline between injections this literature does not demonstrate an indication for weekly trigger point injections. This does represent that there are a variety of protocols used for administration of TPI ranging from weekly to 3 months and there is a lack of evidence on best practice for timing between injections.

In 2001, ASIPP recommends weekly injections during the diagnostic phase which was limited to no more than 4 times per year and at least 2 months apart thereafter to a maximum of 6/12 months.⁸ There was no supporting evidence for these recommendations at that time.

The frequency of trigger point injections is not well established in the literature, but most experts agree that the benefit should last at least 4 weeks and typically several months. This aligns with expert opinions from the SMEs and most societal guidance.¹⁶ However, we agree there is a lack of evidence to support the requirement for 6 weeks duration between injections so this is removed from the LCD. The number of injections allowed is not changed as this aligns with the available evidence on the short-term benefit from TPIs and lack of evidence for longer term use so additional injections are not supported by evidence. 

The same commenter objects to the requirement of a pain scale at baseline and states that using a pain scale is complicated and that functional measurements are more practical. He also objects to requiring a functional scale for measurement of ADLs asking questions that demonstrate improvement in pain and function is sufficient.

No supporting evidence was submitted. A pain scale is necessary to determine if the injections are effective and required to determine if pain, function, or both are improved because of the TPI. The provider can select the pain or functional scale of choice which must be documented at baseline and before any subsequent injections to ensure criteria to receive further treatment is met.

The same commenter recommends removal of the language that addresses subsequent TPI requirements and provides suggestions for new requirements. The new suggestion is an improvement of pain by 10% or more for at least one week or sooner if pain reoccurs or worsens during treatment measured by visual analog scale (VAS) without limitations in the number of TPIs with lidocaine. 

No supporting evidence was submitted. Typically, the research conducted on TPI success was defined as ≥ 50% or higher pain relief to measure improvement and therefore aligns with published standards. This is exemplified in a systematic review submitted by the commenter which defines clinical success as >50% pain relief from baseline.¹⁴

The same commenter objects to any limitations on performance of multiple blocks during the same session stating that it is reasonable to perform 2 different procedures in the same session.

No evidence was submitted to demonstrate safety and effectiveness of multiple injections within the same session. If multiple injections are given in the same session, it becomes difficult to understand which injection led to improvement (if any achieved) or duration of treatment if effective.

The same commenter also suggests that language be added to the policy to allow TPIs for treatment of headache or pain in any part of the body if the first treatment worked. 

No supporting evidence was submitted. See section on Headache in the LCD.

The same commenter recommends that language that does not allow TPI for chronic pain syndromes be removed. 

No supporting evidence was submitted. See section on Complex Regional Pain Syndrome in LCD.

The same commenter states that trigger point injections should be administered before physical therapy and 8 textbook references were provided however the actual chapter/literature was not provided.

The textbook references are not publicly accessible. In the summaries provided, they discuss cases and expert opinion while reference to studies to address this were not found. Within the LCD Conservative Measure section published literature is reviewed to demonstrate that early physical therapy may lead to rapid resolution of symptoms and avoid interventions such as injections. The SMEs agreed in cases of severe pain, an injection can help aid in pain relief and allow physical therapy to be more effective. It was the input from the SMEs that led to the initial injection being allowed after non-invasive conservative therapy is not successful as first line treatment OR movement of a joint or limb is limited or blocked OR the TPI is necessary for diagnostic confirmation. Therefore, administering the injection in patients who meet the criteria in the LCD prior to conservative therapy is not prohibited by the LCD.