Which one is more effective for the clinical treatment of chronic pain in knee osteoarthritis: radiofrequency neurotomy of the genicular nerves or intra-articular injection?

OBJECTIVES: To compare the efficacy of intra-articular injection and radiofrequency (RF) neurotomy of genicular nerves in patients with chronic knee osteoarthritis (OA) pain.

METHODS: Seventy-three patients with knee OA were included in the study. Patients were randomly assigned to Group IA (intra-articular 2.5 mL of bupivacaine, 2.5 mg of morphine and 1 mL of betamethasone, 6 mL of fluid injection) or Group RF (RF neurotomy of the genicular nerves). The outcome measures included a pain scale (visual analog scale, VAS) and Western Ontario and McMaster Universities (WOMAC) Index of Osteoarthritis.

RESULTS: No statistically significant difference was found between the two groups in baseline VAS-pain. In Group RF, a significant reduction was observed in VAS-pain at the first month (P < 0.001) and the third month (P < 0.001) in comparison to Group IA. Also in Group RF, a significant reduction was observed in WOMAC total scores in the first month (P < 0.001) in comparison to Group IA.

CONCLUSION: This study is the first controlled study in the literature which compares RF genicular nerve to intra-articular injections. This study demonstrated that genicular nerve RF neurotomy is a safe and efficient treatment modality and provides functional improvement along with an analgesia in patients with chronic knee OA.