Efficacy of high energy, focused ESWT in treatment of lumbar facet joint pain - a randomized sham-controlled trial.

Objective: Lumbar facet joints (FJ) are a common source of chronic low back pain (LBP). Focused extracorporeal shock wave therapy (ESWT) has demonstrated potential in the treatment of musculoskeletal disorders due to its deeper tissue penetration and safety profile. This study aimed to evaluate the efficacy and safety of ESWT in the management of lumbar facet joint pain.

Methods: A prospective, randomized, sham-controlled trial was conducted in 128 patients with chronic lumbar facet syndrome confirmed by medial branch block. Patients were randomized to receive either focused ESWT (Group A, n = 64; 0.35 mJ/mm2, 1200 shocks/session = 600 shocks per segment, 5 weekly sessions) or sham therapy (Group B, n = 64). Pain intensity (VAS), disability (ODI), and neuropathic pain features (PainDETECT questionnaire) were assessed at 2, 6, and 12 months. Lumbar spine MRI was performed at baseline and 6 months post-treatment.

Results: Group A showed significant reductions in VAS scores at 6 and 12 months (mean 64.4% reduction at 12 months, p<0.01), with an effect size (Cohen's d = 1.12). ODI decreased by 42.3% in Group A compared to 12.5% in the sham group. Neuropathic pain symptoms improved significantly only in Group A (PD-Q reduction from 18.3 ± 2.4 to 10.2 ± 1.9; p<0.01). MRI follow-up demonstrated resolution of bone marrow edema in 58.8% of ESWT-treated patients versus none in the control group. No adverse effects were reported.

Conclusions: High-energy focused ESWT is a safe and effective non-invasive therapy for chronic lumbar facet joint pain, showing sustained improvements in pain, function, and neuropathic symptoms. MRI findings support its biological effect on joint-related bone marrow edema. ESWT represents a promising alternative to interventional pain procedures.