Abstract
BACKGROUND: Knee osteoarthritis is a common musculoskeletal disorder associated with pain, functional limitation, and substantial healthcare burden. PURPOSE: To compare the efficacy of trigger point electrical dry needling (electrical-DN) with different waveforms, combined with intra-articular corticosteroid injection (CSI), in patients with knee osteoarthritis (KOA). METHODS: A total of 138 participants were randomized to the sham stimulation group (Group S), dense-disperse wave group (Group D), or continuous wave group (Group C). All groups received a single CSI. Group S had no electrical stimulation, while Group D and Group C were treated with dense-disperse wave and continuous wave, respectively. Electrical stimulation was administered for 20 minutes per session, once weekly for two weeks. Assessments were obtained at the following time points: baseline, post-treatment weeks 1, 4, 8, and 12. Clinical outcomes were assessed using the numerical rating scale (NRS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Short-Form McGill Pain Questionnaire (SF-MPQ), Pittsburgh Sleep Quality Index (PSQI), Hamilton Anxiety Rating Scale (HAMA), Knee Flexion Range of Motion (FROM), rescue medication use, and adverse events. Repeated measures were analyzed using generalized estimating equations (GEE), and other comparisons were performed using appropriate parametric or nonparametric tests. RESULTS: Group D showed lower NRS scores than Group C at weeks 8 and 12 and a lower WOMAC score at week 12 (all P < 0.05). Compared with Group S, both electrical-DN groups showed lower NRS and WOMAC scores at all follow-up time points. At week 1, both electrical-DN groups also showed lower SF-MPQ scores and greater improvement in FROM than Group S (all P < 0.05). In GEE analysis, with Group S and week 12 as the reference categories, both Group D (β = -1.152, 95% CI: -1.560 to -0.744) and Group C (β = -0.652, 95% CI: -1.033 to -0.271) showed lower NRS scores at week 12. CONCLUSION: Trigger point electrical dry needling may provide additional benefit in pain relief for patients with KOA when used after CSI. Among the two electrical-DN groups, the dense-disperse waveform was associated with a modest advantage in pain relief at later follow-up time points.