This section describes efficacy outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the overview.
A randomised controlled trial of 60 patients treated by bipolar radiofrequency energy (n=30) or by mechanical shaver debridement (n=30) reported that patients in the bipolar radiofrequency energy group returned to work sooner than patients in the mechanical shaver debridement group (16.4±6.5 days compared with 21.7±6.1 days, p=0.002).
In the randomised controlled trial of 60 patients treated by bipolar radiofrequency energy or mechanical shaver debridement, non‑steroidal anti‑inflammatory drugs were taken by 2% of patients in the bipolar radiofrequency energy group and 23% of patients in the mechanical shaver debridement group at 1‑year follow-up (p=0.026).
In the randomised controlled trial of 60 patients treated by bipolar radiofrequency energy or mechanical shaver debridement, mean Knee injury and Osteoarthritis Outcome Score (KOOS) for pain, symptoms, activities of daily living, sports and quality of life (higher scores indicating better outcomes) were 81.2, 80.8, 81.5, 81.7 and 80.2 respectively in the bipolar radiofrequency energy group and 57.9, 58.3, 58.8, 57.3 and 56.2 respectively in the mechanical shaver debridement group at 1‑year follow-up (p<0.001 for all inter‑group comparisons). At 4‑year follow-up, patients in the radiofrequency group continued to report significantly higher scores than patients in the mechanical shaver debridement group. Mean KOOS scores for pain, symptoms, activities of daily living, sports and quality of life were 75.1, 72.7, 69.9, 75.0 and 67.0 respectively in the radiofrequency group (n=25) and 55.7, 53.1, 50.9, 56.7 and 52.9 respectively in the mechanical shaver debridement group (n=15; p<0.001 for all inter-group comparisons).
In a prospective case series of 15 patients (25 knees) treated by bipolar radiofrequency energy, the mean size of chondral defects decreased from 170.2 mm2 (range 9 to 625 mm2) at initial arthroscopy to 107.7 mm2 (range 0 to 300 mm2) at follow-up arthroscopy after a mean of 10.4 months: 32% (8 out of 25) of defects showed no progression of degeneration; 32% (8 out of 25) showed partial healing; and 24% (6 out of 25) had healed completely. Twelve per cent (3 out of 25) of defects showed unstable borders with progressive damage to the surrounding cartilage.
A randomised controlled trial of 60 patients treated by monopolar radiofrequency energy plus mechanical shaver debridement (n=30) or by mechanical shaver debridement only (n=30) reported that mean International Knee Documentation Committee (IKDC) scores improved from 36 to 69 (p<0.05) and from 35 to 68 (p<0.05) respectively at a mean follow-up of 19 months (higher scores indicating better outcomes). No statistically significant differences in postoperative scores were observed between groups.
The specialist advisers stated that key efficacy outcomes include MRI findings and functional scores such as the Tegner, IKDC and Lysholm scores.