• 
• 

Three Part Question

In [adults with low back pain] are [trigger point injections compared to standard therapy] more effective in [reducing pain and disability].

Clinical Scenario

A 65-year-old obese female with a history of atrial fibrillation and chronic back pain returns to the emergency department for exacerbation of her low back pain. Her vitals are normal and her exam reveals reproducible paralumbar muscular tenderness consistent with previous exams. You would like to treat her pain but are concerned about her risk of falling at home given her risk factors of age, anticoagulant use, and polypharmacy. You wonder about the effectiveness of trigger point injections for this patient’s musculoskeletal pain.

Search Strategy

Medline 1966-04/20 using PubMed, Cochrane Library (2020), and Embase
[exp low back pain OR exp myofascial low back pain OR exp sciatica OR exp radiculopathy) AND (exp trigger point injection)]. Limit to English language

Search Outcome

14 studies were identified; four addressed the clinical question.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Saeidian SR et al. Oct 2014 Ahwaz, Iran	98 non-surgical patients with chronic lumbosacral radicular back pain undergoing conservative management. 64 of these patients had clinical trigger points and were divided into two even groups to receive standard care (N-group) or trigger point injections of lidocaine/triamcinolone (TP-group).	Prospective comparative trial	Pain scores following treatment	2.4 in TP group and 4.06 in N group (P= 0.008)	Unblinded, single-center, non-randomized, not placebo-matched
			Straight leg raising test	Negative in all patients in TP group but only in 19% patients in N group (P = 0.001).
Garvey TA, et al Aug 1989 USA	63 patient with low back strain divided into 4 groups (lidocaine injection, lidocaine + steroid, acupuncture, and acupressure)	RCT	Binary subjective pain report at 2-weeks post-intervention	42% pain improvement with medication injection vs. 63% pain improvement with non-medication injection (P=0.09). 3 patients had worsened pain after injections, 1 patient had fever, chills and went to ED after injection.	20% lost-to-follow-up rate, subjective binary pain report, no studied pain recurrence, inadequately powered study.
Dernek B, et al April 2018 Istanbul, Turkey	65 patient with back pain related to lumbar disc herniation. Group 1 (30) had gluteal trigger point injection with prilocaine plus conservative therapy. Group 2 (35) only had conservative therapy.	Prospective, comparative study	Visual Analog Scale	VAS scores at 1 and 3 months were significantly lower in the intervention group versus the control group	Herniated-disc back pain only, unblinded
			Oswestry Disability Index scores	ODI scores at 1 and 3 months were significantly lower in the intervention group versus the control group
Kocak AO, et al Oct 2019 Erzurum, Turkey	54 patients presenting to ED for acute muscular low back pain. Group 1 (32) received IV NSAIDs (dexketoprofen) and Group 2 (22) received 2% lidocaine trigger point injection.	RCT	Visual Analogue Scale (VAS) in 5, 10, 15, 30, and 60 minutes	Pain scores decreased significantly in the TPI group. During the 60 min’ follow-up period, mean VAS pain score decreased to 0.41 in the TPI group and to 2.59 in the NSAID group	Not placebo-matched, unblinded. Excluded chronic and radicular pain, small study, unknown reproducibility of trigger points on exam, unknown long-term (> 60 min) response to therapy or adverse reactions.
			Side effects	None reported

Comment(s)

Trigger point (TP) injection is a simple procedure designed to reduce or relieve the back pain caused by trigger points. These are irritable knots of muscle form and may manifest as palpable nodules. Trigger points may irritate the nerves around them, and cause referred pain, or pain that is felt in another part of the body. These four studies show that TP injections improve patient pain scores compared to non-invasive, standard therapies. The actual medications used for the TP injection does not appear to matter (local anesthetic with/without steroid) and improvement in pain can be related to mechanically-mediated pathways that do not require medications at all (acupuncture, spray and stretch, ultrasound, or manipulative therapy). The different results obtained by various studies may be due to a failure to precisely localize the TP or injection of a spot adjacent to the TP may also yield unsatisfactory results

Clinical Bottom Line

Trigger point injections can help reduce pain scores for low back pain patients in the emergency department. Although poorly studied, trigger point injections appear to be a safe adjunct to typical musculoskeletal pain treatments.

References

1. Saeidian SR, Pipelzadeh MR, Rasras S, Zeinali M Effect of Trigger Point Injection on Lumbosacral Radiculopathy Source Anesth Pain Med 2014 Oct; 4(4): e15500.
2. Garvey TA, Marks MR, Wiesel SW. A prospective, randomized, double-blind evaluation of trigger-point injection therapy for low-back pai Spine 1989, 14(9):962-964
3. Dernek B, Adiyeke L, Duymus TM, Gokcedag A, Kesiktas FN, Aksoy C. Efficacy of Trigger Point Injections in Patients with Lumbar Disc Hernia without Indication for Surgery Asian Spine J 2018;12(2):232-237.
4. Kocak AO, Ahiskalioglu A, Sengun E, Gur STA, Akbas I Comparison of intravenous NSAIDs and trigger point injection for low back pain in ED: A prospective randomized study Am J Emerg Med 2019;37(10):1927-1931