EfficacyandEffectivenessofExtracorporealShockwaveTherapyinPatientswithMyofascialPainorFibromyalgia:AScopingReview

Myofascial pain syndrome (MPS) and fibromyalgia (FM) are painful musculoskeletal conditions that significantly impact function and quality of life. MPS is characterized by regional pain from myofascial trigger points, while FM involves widespread pain with fatigue, sleep disorders, and cognitive symptoms. Despite various treatment options including drugs, exercise, and physical therapy, no consensus exists on the most effective approach. Prolonged use of medications like NSAIDs and painkillers increases adverse event risks, driving interest in non-pharmacological treatments.

Extracorporeal shockwave therapy (ESWT), available in radial (rESWT) and focused (fESWT) forms, is widely used for musculoskeletal pain but its mechanisms in pain modulation remain incompletely understood. This scoping review aimed to summarize current evidence on ESWT efficacy for MPS and FM.

The authors conducted a PRISMA-ScR compliant scoping review of PubMed literature published through December 31, 2021. They used MeSH terms and keyword combinations for ESWT, MPS, and FM. Eligible studies included clinical trials (randomized and non-randomized) and observational studies in humans, published in English. They excluded meta-analyses, systematic reviews, review articles, conference abstracts, and editorials.

From 76 initial records, after removing duplicates and screening titles/abstracts, 19 studies were included: 12 using rESWT and 7 using fESWT for MPS. No studies met eligibility criteria for FM. The authors qualitatively analyzed treatment protocols, outcomes, and findings, and proposed a new ESWT protocol for FM based on updated diagnostic criteria.

For rESWT in MPS (10 RCTs, 1 case-control, 1 retrospective study), qualitative analysis showed beneficial effects on pain and functional outcomes. Two RCTs found rESWT comparable to laser therapy for pain and disability reduction. Two RCTs showed rESWT equally effective as ultrasound therapy, with both superior to sham or exercise alone. One RCT demonstrated rESWT superior to combined hot packs, TENS, and ultrasound for pain, sleep quality, disability, depression, and quality of life. rESWT was superior to phonophoresis for pain and neck disability.

Three RCTs found rESWT and dry needling equally effective for pain and disability, though dry needling caused post-treatment soreness in one study. rESWT was more effective than corticosteroid trigger point injection at 1 month for pain, disability, and quality of life. One case-control study found rESWT more effective than ultrashort wave for temporomandibular joint pain and function.

For fESWT in MPS (5 RCTs, 2 retrospective studies), results were more mixed. Two RCTs found fESWT superior to ineffective or low-energy ESWT for pain and disability. One RCT showed combined fESWT and topical diclofenac superior to diclofenac alone for pain, range of motion, and pressure pain threshold. However, one RCT found no significant between-group differences between fESWT and TPI plus TENS for pain or mobility.

One RCT showed fESWT superior to control for plantar fasciitis-related gastroc-soleus trigger points at 8 weeks. Retrospective studies found fESWT more effective than corticosteroid injection for pain at 1 month (but not disability), and ESWT plus exercise superior to kinesiotaping plus exercise or exercise alone for pain and neck function.

No eligible studies were found for FM, representing a significant evidence gap. Treatment protocols varied substantially across studies in number of sessions (1-7), intervals, shockwave counts (1000-4500 for rESWT, 1000-3000 for fESWT), and energy flux density.

ESWT appears to have a role in MPS management, with both radial and focused modalities showing pain relief and functional improvement. rESWT has more consistent evidence of benefit, particularly when compared to sham or physical agent combinations. The comparable efficacy to established treatments like dry needling and ultrasound, with potential advantages over some pharmacological injections, makes it a viable non-pharmacological option. However, the lack of standardized protocols limits clinical implementation. The complete absence of FM studies is striking given the overlapping pathophysiology with MPS.

The authors propose distributing 3000 shocks (fESWT) or 4500 shocks (rESWT) across affected body regions (600-900 or 750-1100 per region for 5 or 4 regions respectively) for FM patients, tailored to tolerability. Clinicians should note that while ESWT shows promise for MPS, treatment parameters need individualization, and patients with FM currently lack evidence-based ESWT protocols. Future research must address FM specifically and establish optimal dosing parameters for both conditions.