| Objective: To observe the effect of prolotherapy combined with transcranial direct current stimulation in the treatment of knee osteoarthritis pain and explore its mechanism. Methods: Totally, 40 patients with knee osteoarthritis were selected according to the inclusion criteria. According to the different treatment methods, 40 patients were randomized to prolotherapy + active tDCS group and prolotherapy + sham tDCS group, 20 patients in each group. Both groups were given injection of 8 mL of 20% dextrose, once a week for a total of 3 times. At the same time, the prolotherapy + active tDCS group was subjected to a constant current intensity of 2 mA for 20 min once a day for 2 weeks. For the prolotherapy + sham tDCS, the electrodes were placed in the identical positions as for active tDCS, but included only 15-s of 2 mA of stimulation at the beginning and the end to mimic somatosensory perception of active tDCS. The outcome measures included the Visual Analog Scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), pressure pain threshold (PPT) and conditioned pain modulation (CPM) which were obtained from patients before the first injection at the base line and 2, 4, 6 weeks after the first injection. Results: In the prolotherapy + active tDCS group, scores of the VAS and WOMAC were significantly reduced and PPT and CPM increased at 2, 4, 6 weeks after the first injection (P<0.05). In the prolotherapy + sham tDCS group, scores of the VAS and WOMAC were significantly reduced and PPT increased at 2, 4, 6 weeks after the first injection (P<0.05). The CPM in the prolotherapy + sham tDCS group had no significant change at different time points after injection (P>0.05). The VAS score in the prolotherapy + active tDCS group was significantly lower than that in the control group at 2, 4 and 6 weeks after the first injection. There was no significant difference in WOMAC and PPT between the two groups. The CPM in the prolotherapy + active tDCS group was significantly higher than that in the control group at 2, 4 and 6 weeks after the first injection. Conclusion: Prolotherapy combined with tDCS has a higher magnitude of effect than prolotherapy alone. The combined therapy can not only solve the pain caused by tissue structural lesions, but also solve the pain caused by neuroplastic changes. |
