Trigger Point Injections for Back Spasms and Chronic Back Pain
Trigger point injections (TPIs) can provide temporary symptomatic relief for selected patients with back spasms and chronic back pain, but they are NOT recommended for long-term management and should only be used as part of a comprehensive treatment approach that includes physical therapy and other conservative measures. 1
Evidence-Based Recommendations
Short-Term Use Only
The Journal of Neurosurgery guidelines explicitly state that TPIs are not recommended as a treatment option for long-term relief of chronic low-back pain. 1
TPIs are recommended only as a treatment option to provide temporary, symptomatic relief in selected patients with chronic low-back pain. 1
There is insufficient evidence to recommend TPIs as a treatment standard or guideline for chronic back pain management. 1
Clinical Effectiveness
Research demonstrates that TPIs can effectively inactivate trigger points and provide prompt relief of symptoms in the short term. 2
Trigger points are discrete, hyperirritable spots in taut bands of skeletal muscle that produce local and referred pain patterns, commonly affecting postural muscles in the neck, shoulders, and pelvic girdle. 2
A 2024 study showed that lidocaine trigger point injections (both intramuscular and intraosseous) reduced pain severity by 41.7-84.7% immediately after treatment in patients with residual pain after spinal surgery, with effects lasting at least 2 months. 3
Intraosseous TPIs demonstrated 92% greater effectiveness compared to intramuscular TPIs in treating residual lumbar pain. 3
Specific Anatomical Considerations
The quadratus lumborum muscle is an important but often overlooked source of lower back and buttock pain that responds well to trigger point injections. 4
A landmark-based injection technique for quadratus lumborum trigger points reduced pain scores from a mean of 5.6/10 to 0.3/10 after 1-8 treatments, with effects maintained during a mean 73.5-day follow-up period. 4
Treatment Algorithm
Patient Selection Criteria
Identify true myofascial trigger points through palpation of hypersensitive bundles or nodules of muscle fiber with harder than normal consistency. 2
Confirm that palpation elicits pain directly over the affected area and/or causes radiation toward a zone of reference with a local twitch response. 2
Ensure pain is primarily muscular in origin rather than radicular, facetogenic, or discogenic (TPIs do not address these alternative pain generators). 1
When to Use TPIs
Consider TPIs when conservative measures (physical therapy, NSAIDs, activity modification) have been attempted but acute symptom relief is needed. 2, 5
Use TPIs for acute trauma or repetitive microtrauma-induced muscle pain affecting postural muscles. 2
TPIs may be appropriate for patients with decreased range of motion in affected muscles due to trigger point-related pain. 2
Treatment Technique
Inject dilute solutions of local anesthetic (typically 0.5% lidocaine) directly into identified trigger points. 4, 3
For deeper muscles like quadratus lumborum, use 60-90mm, 28G needles advanced until the tip touches the transverse process. 4
Intraosseous injections (into posterior superior iliac spine or L5-S1) provide superior analgesia compared to intramuscular injections. 3
Fluoroscopic or ultrasound guidance is not mandatory for superficial trigger points but may improve accuracy for deeper structures. 4
Expected Outcomes and Limitations
Expect temporary pain relief lasting weeks to months, not permanent resolution. 1, 3
Plan for 1-4 treatments in acute/subacute cases and 2-8 treatments in chronic cases. 4
Analgesic effects typically persist for at least 2 months after treatment completion but gradually diminish. 3
Critical Caveats
What TPIs Cannot Treat
Do not use TPIs for radicular pain (pain radiating below the knee from nerve root compression)—epidural steroid injections are more appropriate for this indication. 6, 7
Do not use TPIs for facet-mediated pain—medial branch blocks or radiofrequency ablation are more effective for confirmed facetogenic pain. 6
Do not use TPIs as a substitute for addressing underlying pathology such as herniated discs, spinal stenosis, or structural instability. 1
Integration with Comprehensive Care
TPIs must be combined with physical therapy, patient education, and appropriate oral medications—they should never be used as monotherapy. 7
Continue conservative treatments (stretching, strengthening exercises, posture correction) even when TPIs provide temporary relief. 2, 5
Consider non-invasive alternatives first, including spray and stretch technique, transcutaneous electrical stimulation, massage, and manipulative therapy. 5
Safety Considerations
Use the lowest effective dose of local anesthetic (bupivacaine doses up to 175-225mg may be used, but should not exceed 400mg in 24 hours). 8
Monitor for systemic toxicity signs including restlessness, anxiety, dizziness, tinnitus, blurred vision, or tremors. 8
Be aware of potential complications including infection, bleeding, pneumothorax (with thoracic injections), and allergic reactions to local anesthetics or preservatives. 8
Alternative Approaches When TPIs Fail
If trigger point injections provide minimal or no relief, reconsider the diagnosis—the pain may be facetogenic, discogenic, or from sacroiliac joint pathology rather than myofascial. 6
For confirmed facet-mediated pain, proceed with diagnostic medial branch blocks followed by radiofrequency ablation if blocks provide >50% temporary relief. 6
For radicular symptoms with imaging-confirmed nerve root compression, consider epidural steroid injections instead. 7
Jet injection systems can deliver local anesthetic with significantly less procedural pain than conventional needle injections and may be preferred by patients. 9