Comparison of Different Treatment Regimens of Extracorporeal Shockwave Therapy in Chronic Low-back Pain: A Randomized Controlled Trial.

BACKGROUND

Extracorporeal shockwave therapy (ESWT) has shown its efficacy in treating chronic pain. Previous evidence has proven that ESWT in patients with chronic low-back pain (CLBP) results in significant reductions in pain. However, the optimal regimen for conducting ESWT in these patients remains unknown.

OBJECTIVES

This study aimed to investigate, under the same total energy dose, the effectiveness and safety of low-intensity versus medium-intensity ESWT on CLBP.

STUDY DESIGN

A prospectively registered, randomized controlled trial in accordance with the Consolidated Standards of Reporting Trials (CONSORT) Statement. The study was registered at the Chinese Clinical Trial Registry (No. ChiCTR2100049871). This study was approved by the ethics committee of our hospital (No.2021-193).

SETTING

A tertiary hospital in China.

METHODS

Sixty-nine patients with CLBP were randomly allocated into either the low-intensity (LI) or the medium-intensity (MI) group. In a 2-week treatment course, patients in the LI group received 6 sessions of ESWT (0.03 millijoules [mJ]/mm2) and patients in MI group received 2 sessions of ESWT (0.09 mJ/mm2). Outcome assessments included the Visual Analog Scale (VAS) at rest and at movement, the Oswestry Disability Index (ODI), and the Hospital Anxiety and Depression Scale (HADS). Follow-up visits were scheduled at 2 weeks, 4 weeks, 6 weeks, and 3 months after randomization. The primary outcome was the 11-point VAS at movement reported at 4 weeks after randomization. Adverse events were recorded. Overall therapeutic satisfaction on a 5-point Likert scale was collected at the last follow-up.

RESULTS

From August 2021 through December 2021, 69 eligible patients were enrolled in the randomized controlled trial; 68 patients completed the whole treatment. Compared with baseline, both the LI group and MI group manifested significant improvement in VAS, ODI, and HADS scores at each follow-up time point (all P < 0.05). The between-group comparison indicated that the LI group had lower VAS scores at movement at 2 weeks, 4 weeks and 6 weeks after randomization (all P < 0.05), while the VAS score at rest was significantly lower in the LI group than in the MI group (P = 0.018) at 6 weeks after randomization. The ODI score in the LI group was significantly lower than the MI group at 2 weeks and 6 weeks after randomization (both P < 0.05). In addition, the HADS score was lower in the LI group than the MI group at 2 weeks after randomization (P = 0.021). However, at 3-months follow-up, no significant difference in VAS, ODI, or HADS were observed between the 2 groups. No notable shockwave-related side effects occurred in either group.

LIMITATION

The limitations of our study include the small sample size and the lack of an untreated control group.

CONCLUSION

Low-intensity ESWT treatment with more sessions is more effective in relieving pain and improving disability in the short-term than medium-intensity treatment with fewer sessions under the same total energy dose.