To evaluate the long-term efficacy and safety of ultrasound-guided warm needle knife therapy for patients with advanced knee osteoarthritis (KOA).

A total of 70 advanced KOA patients were recruited from the Department of Pain and Rehabilitation of the Third Hospital of Wuhan from June 2020 to June 2022. They were randomized to a treatment group or a control group in a 1:1 ratio. Patients in the treatment group received ultrasound guided warm needle knife treatment, while patients in the control group received ultrasound guided radiofrequency treatment of the knee sensory plexus, both for 1 time. The primary outcome was the changes in Western Ontario McMaster University Osteoarthritis Index (WOMAC) scores. Other outcomes included the Visual Analogue Pain Scale (VAS) scores, value of Young's modulus of A-shi points, proportion of patients achieving improvement, and adverse events related to study interventions.

Compared with baseline, the WOMAC and VAS scores in the two groups were significantly decreased at each timepoints (P<0.05), and the value of Young's modulus was significantly decreased at 12 months after treatment. Compared with the control group, the treatment group reported a significantly greater reduction in WOMAC and VAS scores at 6 months and 12 months after treatment (P<0.05). The proportion of patients achieving improvement in the treatment group were significantly higher than the control group at 12 months after treatment (P<0.05). The value of Young's modulus in the treatment group was significantly lower than the control group at 12 months after treatment (P<0.05). No adverse events were reported.

Ultrasound guided warm needle knife is effective in improving the function of knee joint and relieving pain in patients with advanced KOA. Further, the long-term efficacy of ultrasound guided warm needle knife for advanced KOA was superior to the ultrasound guided radiofrequency therapy.