Ting K, Huh A, Roldan CJ. Review of Trigger Point Therapy for the Treatment of Myofascial Pain Syndromes. J Anesthesiol & Pain Therapy. 2020;1(3):22-29 Review Article Open Access Review of Trigger Point Therapy for the Treatment of Myofascial Pain Syndromes Kimberly Ting1, Albert Huh1, Carlos J. Roldan1,2* 1Department of Pain Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA 2McGovern Medical School at The University of Texas Health Science Center at Houston (UTHealth), Houston, Texas, USA Article Info Abstract Article Notes Scope of the investigation: No standard protocol has been established Received: October 08, 2020 for the treatment of myofascial pain syndrome (MPS). Invasive therapies such Accepted: November 25, 2020 as dry needling and trigger point injection (TPI) with active pharmacological *Correspondence: agents are commonly used. Growing evidence suggests the efficacy of TPI is *Dr. Carlos J. Roldan, Department of Pain Medicine, MD independent of the injectate selected. Normal saline (NS) solution has been Anderson Cancer Center, Houston, Texas, USA; Email: described as an efficient injectate used in TPI for the treatment of MPS. [email protected]. Methods: A broad literature search was performed to compare the use of NS ©2020 Roldan CJ. This article is distributed under the terms of and other pharmacological agents as the injectate in TPI for the treatment of MPS. the Creative Commons Attribution 4.0 International License. Results: We identified 13 reports comparing the safety and efficacy of NS Keywords with that of botulinum toxin A or local anesthetic with or without steroid in TPI. Normal saline Trigger point therapy Conclusion: Pain of myofascial origin can be adequately treated with TPI Myofascial pain independent of the injectate used. The use of NS in TPI offers lower cost, safety, and a more favorable side effect profile than other TPI injectates. Introduction Myofascial pain syndrome (MPS) is characterized by painful manifestations originating in the muscles and fascia. The etiology of MPS includes trauma, repetitive muscle strain, physical inactivity, skeletal asymmetry, poor posture, systemic disease, and neuromusculoskeletal lesions1,2. MPS is also thought to be caused by trigger points, taut bands of skeletal muscle that can produce local and referred pain when provoked1,3,4. Overall, MPS has a lifetime prevalence of up to 85% in the general population and more often affects women between 15 and 40 years of age4,5. In a study by Skootsky et al., the authors found that among the patients who originated in the myofascial tissue4. The diagnosis of myofascial pain ispresented even more to prevalenta primary in care patients office presenting visit for pain, to a 30% pain hadmanagement pain that clinic, with proportions cited as high as 93% 6. While myofascial pain can be present as the sole pain generator, it is not uncommon for it to be part of a constellation of other pain syndromes. Although the connections are not clearly understood, MPS has been associated with other pain conditions such as 7–9. In patients with MPS, treatment should not be focused on the symptomatic reliefmigraines, of the fibromyalgia, myofascial spinal pain pain,alone; and a osteoarthritis comprehensive approach should include managing the underlying conditions and preventing recrudescence of the myofascial pain. Treatment options for MPS range from conservative approaches to invasive procedures. Some studies have shown nonsteroidal Page 22 of 29 Ting K, Huh A, Roldan CJ. Review of Trigger Point Therapy for the Treatment of Myofascial Pain Syndromes. J Anesthesiol & Pain Therapy. 2020;1(3):22-29 Journal of Anesthesiology and Pain Therapy a comprehensive literature review, Zhou et al. found mixed myofascial pain; however, these are often used in conjunction results when using this agent as the injectate in TPIs16. withnti-inflammatory other treatments drugs6,10 .to Other be an pharmacological effective treatment agents in Previous and recent studies using normal saline for TPI have such as antidepressants, anticonvulsants, and narcotics are shown great results in treating MPS. In a study by Roldan et al., also used to treat myofascial pain, but studies have shown the authors found that normal saline was non-inferior when 11 limits in their effectiveness . A non-randomized study by compared to traditional treatment mixes of local anesthetics Haviv et al. with 42 patients showed that amitriptyline/ plus triamcinolone acetonide15. This calls into question the nortriptyline and gabapentin have been used successfully use of injectates other than normal saline, given that normal in the treatment of myofascial pain; however, these results saline is very inexpensive and has no side effects. This review 12 have not been validated . Other studies have reported that article analyzes the current literature on the effectiveness of home stretching exercises and physical therapy are both normal saline compared to these other injectates on outcomes effective in reducing pain and can be used as adjuncts in including pain, stiffness, and quality of life. any treatment program6,13. Data Acquisition Invasive procedures aimed at diffusing the trigger point of the muscle that is compromised are extensively A comprehensive search of the literature was performed in September 2020 using the Medline (Ovid), Embase (Ovid), in the treatment of MPS. These include dry needling and and Scopus databases. The search applied both controlled triggerused in pointdifferent injection clinical (TPI). settings Based and on have the theories shown efficacy behind vocabulary and natural language terms for saline, normal the pathophysiology of MPS, mechanical disruption of the saline, trigger point injections, and trigger point therapies. trigger point has emerged as a practical treatment option. Results were limited to English language and human studies In a review by Cummings et al., the authors concluded that published from 2008 to the present. A total of 24 citations and direct needling of myofascial trigger points was an effective treatment14 and abstracts, six were irrelevant to the topic, one was for aabstracts review werearticle, identified one was by for this an search. article Of that those was 24 retracted, citations studies. This finding has been supported by other and one was for an article that we could not access/obtain, TPIs with various injectates are commonly used to resulting in a total of 15 articles. Of these articles, most treat MPS10. However, numerous authors have called into question the traditional use of local anesthetics mixed with BoNT-A to normal saline, and two compared normal saline steroids in TPIs15,16. Thus, botulinum toxin A (BoNT-A) tocompared local anesthetic local anesthetic plus steroid, to normal the conventional saline, five active compared drug has emerged as an alternative injectate; however, in a mixture (CADM) (Table 1). Table 1: Overview of the randomized controlled trials in trigger point therapy using injectate included into the review Adverse Type of Anatomical Reference Size Intervention Primary Outcomes Secondary Outcomes events/Side Limitations Study Location effects Double-blind, Group 1: Saline No clear correlation The soft tissue stiffness of random- containing 5 units of between soft tissue No statistically single neck muscles is not Ojala, T. A., ized, and botulinum toxin A stiffness and self-re- significant side Small sam- Neck-shoulder N=31 changed after injections et al. (2010) controlled ported or clinically effects in any ple size of saline or small doses of crossover Group 2: 0.05 mL of assessed pain and groups botulinum toxin A trial normal saline disability Immediately after TPI, the mean pain intensity was Iliocostalis reduced by 5.48 in the NS lumborum, group (p ≤ 0.001) and 5.68 Small iliocostalis in the CADM group (p ≤ sample size. thoracis, 0.001) Overall, the mean Patients quadratus pain scores from prior to the received a Random- lumborum, Group 1: N=23; TPI TPI to ED discharge were heter- ized, paraspinal with normal saline (NS) reduced by 6.17 (p ≤ 0.001) At 2 weeks, the mean No statistically ogenous blinded, - cervical, Roldan, C. J., in the NS arm and 5.96 (p ≤ pain scores were significant side quantity controlled, paraspinal N=48 Group 2: N= 25; et al. (2019) 0.001) in the CADM arm. similar between the effects in any and types non-inferi- - thoracic, lidocaine 1% 10cc and The size of the effect for the groups groups of pain ority trial paraspinal triamcinolone 40 mg/ NS arm was 2.88, and 1.04 medications - lumbar, piri- mL (CADM) patients would need to re- prior to formis, gluteus ceive treatment to observe the trigger medius, trape- a benefit. The size of effect point injec- zius, latissimus for the CADM arm was 2.51, tions. dorsi and 1.08 patients would need to receive treatment to observe a benefit. Page 23 of 29 Ting K, Huh A, Roldan CJ. Review of Trigger Point Therapy for the Treatment of Myofascial Pain Syndromes. J Anesthesiol & Pain Therapy. 2020;1(3):22-29 Journal of Anesthesiology and Pain Therapy Pain was reduced in 87.71% Temporalis of patients injected with sa- muscle for Group 1: N=16 control line and 100% injected with Random- masticatory Small anesthetic. Similar results No statistically ized, con- myofas- Group 2: N=14 normal sample size. Sabatke, S., were obtained for headache significant side trolled, dou- cial pain N=47 saline None Only female et al. (2015) frequency. With regard to effects in any ble-blind syndrome, partici- headache