To evaluate the effectiveness and safety of radiofrequency (RF) ablation and neuromodulation modalities for knee osteoarthritis (OA).
The Pubmed, Medline, Embase, and Cochrane Library databases were searched from inception to August 2018. All comparative and noncomparative studies that reported clinical outcome measures and adverse events related to RF modalities for knee OA were included. Pain scores, physical function measures, quality of life (QOL), patient satisfaction, and adverse events for three months and beyond of postprocedure follow-up were analyzed qualitatively.
Thirty-three studies, including 13 randomized controlled trials (RCTs), two nonrandomized comparative studies, and 18 noncomparative cohort studies, were identified, with 1,512 patients (mean age = 64.3 years, 32.5% males). All 33 studies were considered to be of moderate or high methodological quality. All 33/33 (100%) studies reported alleviation of OA-related knee pain from baseline until three to 12 months with RF modalities, with six comparative studies reporting 194/296 (65.5%) and 29/150 (19.3%) RF and control patients achieving >50% pain relief, respectively. Three of the 33 studies reported QOL, with three of three studies (100%) achieving improvements in disease-specific QOL from baseline until three to 12 months. Twenty-eight of the 33 studies reported functional outcomes, with 27/28 (96%) studies obtaining enhanced functionality from baseline up until three to 12 months. Ten of the 33 studies reported patient satisfaction, with eight of 10 studies (80%) indicating that patients were significantly satisfied after RF procedures, and from these eight studies, four were comparative studies that indicated that 86/154 (56%) and 33/104 (32%) RF and control patients were extremely satisfied or satisfied, respectively. Regarding adverse events (AEs), 29 of the 33 studies reported AEs, with 20/29 (69%) studies indicating no AEs related to the RF modalities and the remaining nine studies only indicating minor localized AEs. Twenty-nine of the 33 studies indicated no serious knee-related AEs pertaining to RF modalities.
Current evidence substantiates that RF modalities for knee OA potentially improve pain, functionality, and disease-specific QOL for up to three to 12 months with minimal localized complications. This suggests that RF modalities are perhaps an effective adjunct therapy for patients with knee OA who are unresponsive to conservative therapies. Further RCTs with larger sample sizes and long-term follow-up that directly compare the three primary RF modalities are warranted to confirm the clinical efficaciousness and superiority of these RF modalities for knee OA.