Genicular Nerve Blocks and Ablation for Chronic Knee Pain - CAM 230

Description   
This document addresses genicular nerve blocks and genicular radiofrequency ablation, also called genicular neurotomy, genicular denervation or cooled radiofrequency therapy, as a treatment for the management of chronic knee pain. This document does not apply to regional anesthetic blocks or acute surgical pain. This document does not apply to the use of peripheral nerve blocks (for example, sciatic and/or femoral nerve blocks) as an adjunct to systemic analgesia in the perioperative period for major knee surgery.

Background
Chronic osteoarthritis of the knee is one of the most common diseases of advanced age. With up to 20 million adults in the United States suffering from osteoarthritis of the knee, close to 700,000 cases progress to total knee joint replacement. Many individuals with chronic joint pain, however, are not candidates for invasive procedures due to body mass index, age and other comorbidities. Alternative therapies, including arthroscopic debridement or injections, are associated with less than optimal clinical outcomes. In addition to osteoarthritis, adults can experience knee pain due to a number of other causes, and an estimated 10 – 34% of individuals experience long-term pain after a total knee replacement.

When an individual exhibits knee pain, the pain signals can be generated from the peripheral nerves innervating the knee, including several branches of the genicular nerve. A diagnostic genicular nerve block consists of placing a small amount of local anesthetic on the genicular nerves to determine if there is sufficient pain relief in the knee to justify performing a therapeutic neurotomy. Radiofrequency ablation of the genicular nerves is then performed to restore function and alleviate knee pain.

Policy
Genicular nerve blocks and genicular nerve ablation are investigational and/or unproven and therefore considered NOT MEDICALLY NECESSARY for the treatment of chronic knee pain, including, but not limited to, any of the following:

  • Degenerative joint disease
  • Osteoarthritis of the knee
  • As a treatment prior to knee replacement
  • As a treatment following knee replacement
  • As a treatment for individuals who are not candidates for knee replacement surgery

Rationale
Genicular nerve blocks and genicular radiofrequency ablation are being evaluated in the treatment of chronic knee pain for individuals that have not been effectively managed by pharmacologic or other alternative therapies. A search of the peer-reviewed medical literature identified studies evaluating the use of nerve blocks for the diagnosis and treatment of neuralgias and neuropathic pain conditions; however, there is a lack of adequately designed trials in the peer-reviewed literature concerning the use of genicular nerve blocks and radiofrequency ablation as treatments for chronic knee pain.

In a 2011 randomized controlled trial by Choi and colleagues, the authors investigated whether radiofrequency ablation applied to articular nerve branches (genicular nerves) was effective in treating chronic knee joint osteoarthritis pain. The 38 study participants (who had severe knee osteoarthritis lasting longer than 3 months) were randomized to two treatment arms; radiofrequency ablation (n = 19) or control group (n = 19). Using a visual analog scale, Oxford knee scores, and global perceived effect on a 7-point scale, measurements were taken at baseline, and at 1, 4, and 12 weeks following the procedure. At the 4-week point, the visual analog scores showed the radiofrequency group had less knee joint pain than the control group. Similar findings were noted in the Oxford knee scores. There were no post-procedure adverse events reported during the follow-up period. While this study showed pain reduction in those with chronic knee osteoarthritis pain, the authors concluded that “further trials with larger sample size and longer follow-up are warranted.”

In a 2016 randomized study by Qudsi-Sinclair and colleagues, 28 participants with continued knee pain following total knee arthroplasty were evaluated after having received traditional radiofrequency (n = 14) or local anesthetic and corticosteroid block of the genicular nerves in the knee (n = 14). In this double-blind, randomized study, the participants were followed for 1 year. During the first 3 to 6 months, an improvement in joint function and a reduction in pain were shown, with the results being similar between the two treatment arms. While the study showed improvement in both groups, the sample size was small and the authors noted that further studies should be done with larger sample sizes to determine if there are any long-term adverse effects.

A retrospective review by Innaccone and colleagues (2017) looked at the records of 31 individuals who had radiofrequency ablation of the genicular nerves with analysis of the degree and duration of pain relief following the procedure. In this study population, the majority of individuals had tried at least some type of conservative treatment (physical therapy, steroid or hyaluronic acid injection, oral analgesics) prior to radiofrequency ablation. Out of the 31 participants, 23 were available at a 3-month follow-up with 14/23 participants continuing to describe pain relief. A total of 20 participants were available for a 6-month follow-up and 95% of those participants reported pain relief. While most participants reported pain relief, limitations of the study include retrospective chart review with prospective follow-up, small sample size, lack of a control group, and direct comparison to other conservative treatment measures.

Another retrospective chart review with prospective follow-up by McCormick and colleagues (2017) reported on 33 participants who had previously received genicular nerve blocks and cooled radiofrequency ablation for the treatment of chronic pain from knee osteoarthritis. Primary outcome measure was defined as a combination of 50% or greater reduction in pain numeric rating scale (NRS), Patient Global Impression of Change (PGIC) score consistent with “very much improved” or “improved,” and no total knee arthroplasty. A total of 25 participants were available for survey 6 months following the procedure. The median reduction in pain was 2 on the NRS scale. A PGIC score consistent with “very much improved” or “improved” was achieved after 35% of procedures (95% confidence interval [CI] 22% – 48%). This study has limitations including its retrospective nature and survey design. Prospective studies with larger sample sizes are necessary.

Santana Pineda and colleagues (2017) reported on a prospective study in which 25 participants with chronic osteoarthritis of the knee received radiofrequency ablation of genicular nerves. Follow-up evaluations were done at 1, 6, and 12 months after the procedure. Primary outcome measure was the change from baseline knee pain using visual analog scores. Those who reported an improvement of 50% or greater in pretreatment visual analog scores 1, 6, and 12 months following intervention were 22/25 (88%), 16/25 (64%) and 8/25 (32%), respectively. While improvement was noted following the radiofrequency procedure, the authors stated that “Larger-scale studies are needed to confirm the results and address the safety aspects in other populations.”

In a 2018 study by Davis and colleagues, the authors reported on the safety and efficacy of genicular cooled radiofrequency ablation compared to intra-articular steroid injection for individuals with osteoarthritis of the knee. In this prospective, randomized, cross-over trial, study participants were included if they had a known diagnosis of osteoarthritis of the knee, complaints of knee pain for at least 6 months that was unresponsive to conservative treatment, NRS pain score of 6 or greater, Oxford Knee Score (OKS) of 35 or less, positive diagnostic genicular nerve block (defined as a decrease of ≥ 50% in NRS score); and if the participant was taking an opioid or other morphine-equivalent medication, the dose was clinically stable. Participants were allowed to use analgesics as needed during the study. A total of 138 participants proceeded to treatment; 67 participants received genicular cooled radiofrequency ablation and 71 participants received intra-articular steroid injection. Participants were assessed at baseline and at 1, 3, and 6 months following treatments. After 6 months of treatment, the participants randomized to the intra-articular steroid cohort were allowed to “cross over” and receive cooled radiofrequency ablation. Using the 11-point NRS, the primary efficacy outcome was the proportion of participants whose knee pain was reduced by 50% or greater from baseline at 6 months after treatment. Secondary outcomes included change in knee function detected by OKS, participant perception of treatment effect as reflected by the Global Perceived Effect (GPE) score, and opioid and nonopioid (nonsteroidal anti-inflammatory drugs) analgesic use measured by self-reported average daily dosage used. The mean baseline pain scores in the cooled radiofrequency group were 76; 7.3 ± 1.2 and were 75; 7.2 ± 1 in the intra-articular steroid group. At the 6-month visit, the NRS score was 2.5 ± 2.3 in the cooled radiofrequency group (n = 58) and 5.9 ± 2.2 (n = 68) in the intra-articular steroid group. A total of 43/58 (95% CI, 62.9 – 85.4) participants in the cooled radiofrequency group and 11/68 (95% CI, 7.4 – 24.9) in the intra-articular steroid group had ≥ 50% reduction in NRS score at 6 months. The mean OKS in each study cohort was equivalent at baseline and mean OKS improved at all end points in both study groups. At 6 months, 53/58 (95% CI, 83.9 – 98.8) participants in the cooled radiofrequency ablation cohort reported improved global perceived effect compared to 16/67 (95% CI, 13.4 – 34.4) of the participants in the intra-articular steroid group. At baseline, 33 participants in the cooled radiofrequency group required nonopioid medication and 34 participants in the intra-articular steroid group required nonopioid medication. At 6 months, mean nonopioid drug dose use was -34.5 ± 128.9 mg in the cooled radiofrequency group and 135.5 ± 391 mg in the intra-articular steroid group. No procedure-related serious adverse events were reported. At 6 months, 74.1% of cooled radiofrequency ablation participants reported reduced index knee pain by at least 50% compared to 16.2% in participants treated with intra-articular steroid injections. GPE improved in 91% of the cooled radiofrequency group compared to 24% in the intra-articular steroid group. Opioid analgesic use was not different between the two groups and remained similar to baseline use. While this study suggests that compared with a single intra-articular steroid injection, cooled radiofrequency ablation provides a reduction in knee pain associated with improved knee function, there are several limitations to this study. The participants received only one intra-articular steroid injection over a 6-month period, the study was not blinded and the study questionnaires were self-administered. There was a lack of a true control group since intra-articular steroid injections are considered analgesics. There was no formal recording of medication usage in this study which allowed for the potential for error and/or inability to identify acute changes in medication dosage during the study. Since participants in both study groups used opioids for medical indications other than osteoarthritis-related knee pain, the effect of each treatment on opioid use could not be specifically measured. Further studies with a true control group and consistent tracking of additional medication usage are necessary to determine efficacy of genicular cooled radiofrequency ablation for osteoarthritis-related knee pain.

As a follow-up to the 2018 Davis cohort, Davis and colleagues (2019) reported on the proportion of individuals from the Davis 2018 cohort who had reduction in knee pain by ≥ 50% from baseline to 12 months. The focus of the Davis 2019 study was to describe the individual’s experience through 12 months. Reduction in knee pain at 12 months was evaluated using the NRS. Secondary endpoints included change in knee function using the OKS, participant perception of treatment measured by the GPE score, and opioid analgesic use by self-reporting. At 12 months, 52 participants in the original group contributed data to the primary endpoint. At 6 months post intra-articular steroid injection, 58 participants crossed over to the cooled radiofrequency ablation treatment group and were assessed at the 12-month follow-up along with 4 participants from the intra-articular steroid injection crossover group. From the original cooled radiofrequency ablation group, using the NRS, mean baseline score was 7.2, mean 1-month score was 3.0, mean 6-month score was 2.5, and mean 12-month score was 3.1. Using the OKS, in the cooled radiofrequency ablation group, mean baseline score was 16.7, mean 1-month score was 33.3, mean 3-month score was 34.6, mean 6 month score was 35.7, and mean 12 month score was 34.3. Using the NRS for the intra-articular steroid injection group, mean baseline score was 7.2, mean 1-month score was 3.9, mean 3-month score was 5.2, mean 6 month score was 5.9, and mean 12 month score was 3.3. With the OKS, the mean baseline score in the intra-articular steroid injection group was 16.9, mean 1-month score was 29.4, mean 3-month score was 24.6, mean 6 month score was 22.4, and mean 12 month score was 22. In the crossover group, the mean NRS score ranged from 3.1 at 1 month, 3.6 at 3 months, and 3.2 months at 6 months. Mean OKS was 18.6 at baseline, 30 at 1 month, 30.3 at 3 months, and 29.8 at 6 months. In the cooled radiofrequency ablation group, the mean total daily dose of opioid analgesic medication was similar to baseline. Between 6 and 12 months, there were 81 adverse events that occurred in the 42 cooled radiofrequency ablation group. These included pain in the index knee, pain in the non-index knee, musculoskeletal pain, and falls. Several limitations of the study include a one-way cross-over option and the small sample size of participants remaining in the intra-articular steroid injection group. Larger sample sizes are necessary.

In another study using the original cohort from the Davis 2018 cohort, Hunter and colleagues (2020) reported on outcomes of participants at 18 and 24 months post cooled radiofrequency ablation. There were 33 participants in the extended outcome study (19 from the cooled radiofrequency ablation arm and 14 from the crossover arm). At 18 months post cooled radiofrequency ablation, 25 participants were evaluated. Using the NRS, mean pain score was 3.1 and OKS was 47.2. At 24 months post cooled radiofrequency ablation, 18 participants were evaluated. Using the NRS, mean pain score was 3.6 and OKS was 46.8. There were 20/25 participants who reported perceived improvement using GPE at 18 months and 12/18 who reported perceived improvement at 24 months. No serious or non-serious adverse events were reported at 18 and 24 months post cooled radiofrequency ablation. This study has several limitations including the small sample size in the extended timeframe, participant exclusion due to the use of alternate methods of treating their osteoarthritis following cooled radiofrequency ablation, and loss of two study investigators. Randomized trials with larger group sizes and control groups are needed to assess efficacy.

In a 2017 meta-analysis by Gupta and colleagues, the authors included 17 studies in which radiofrequency ablation procedures were done for chronic knee pain. Five of the studies were randomized controlled trials with small population groups, 8 were prospective or retrospective case series, and 4 were case reports. Three different types of radiofrequency ablation procedures were performed; conventional, pulsed, or cooled. The three differing methodologies makes it difficult to compare the effectiveness of radiofrequency ablation. Among the studies included, there is a lack of consistent evidence regarding adverse events. With inconsistent procedural methodologies, inconsistent assessment measures, and small study sizes, it is difficult to apply any specific study to clinical practice.

In a 2019 retrospective chart review by Kapural and colleagues, the authors studied the charts of 275 consecutive participants who underwent geniculate nerve blocks in a single-site pain practice. Pain scores were recorded before, immediately after, and long after the procedure. Cooled radiofrequency ablation was then performed in 205 participants under sedation and fluoroscopy. A total of 44 participants had a negative response to the geniculate block (< 50% of pain relief) and 11 participants had long-term pain relief from the block and declined cooled radiofrequency ablation. Eight participants underwent total knee replacement surgery after the block(s) with 7 participants never following up for further treatment. Follow-up was obtained for 183 participants. Most of the participants had a diagnosis of osteoarthritis of the knee. One additional source of chronic pain (back, shoulder, and others) was reported in 146 participants with 2 or more sources of chronic pain reported by 89 participants, and 3 or more sources of chronic pain cited by 39 participants. The average baseline Visual Analog Scale (VAS) pain scores were 8.5 cm, decreased to 2.2 cm after the block, and to 4.2 cm after cooled radiofrequency ablation. A total of 65% of the participants cited > 50% pain relief, while 77% of participants had a decrease of 2 or more VAS points, and 26 participants claimed no pain after cooled radiofrequency ablation. The mean duration of > 50% pain relief after cooled radiofrequency ablation was 12.5 months. The authors noted no significant decrease in opioid use despite improved pain scores. There were 43 participants who had a repeat radiofrequency ablation and there were no significant differences in the magnitude of pain relief after the first and second denervation. In participants who had previous total knee arthroplasty (n = 21), improvements were comparable to the rest of treated participants. No serious side effects were noted after the procedures. Noting no decrease in other medications following the procedures, further research with a control group is necessary to ascertain efficacy of cooled radiofrequency ablation.

In a 2019 study by Yilmaz and colleagues, the authors reported on 40 participants with osteoarthritis of the knee who received either intra-articular steroid injections (n = 20) or intra-articular steroid injections plus genicular nerve block (n = 20). Severity of pain was assessed using a VAS (0 – 10) and the Leeds Assessment of Neuropathic Symptoms and Signs pain scale. Functional status was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Quality of life was assessed by the Nottingham Health Profile. Participants were assessed at baseline, 1 month and 3 months following injections. In the intra-articular steroid injection only group, baseline VAS was 6.75 and 3 month score was 1.50. Leeds Assessment of Neuropathic Symptoms and Signs pain scale at baseline was 13.40 and 6.70 at 3 months. WOMAC score at baseline was 51.57% and 35.06% after 3 months. Quality of life score at baseline was 27.69 and 21.90 at 3 months. In the intra-articular steroid plus genicular nerve block group, baseline VAS was 6.65 and 3.00 at 3 months. Leeds Assessment of Neuropathic Symptoms and Signs pain scale at baseline was 14.35 at baseline and 8.40 after 3 months. Baseline WOMAC was 54.26% and 48.74% at 3 months. Baseline quality of life score was 28.15 and 25.63 at 3 months. The quality of life score in the intra-articular steroid injection plus genicular nerve block group only improved from baseline to 1 month evaluation. While both treatment groups showed improvements in pain and quality of life scores, the intra-articular steroid injection only group showed greater improvements than the steroids plus genicular nerve block group. This study has a small participant size with no comparison between genicular nerve block only to other treatments.

A 2020 retrospective chart review by Konya and colleagues reported on 48 participants who received radiofrequency ablation of genicular nerves for knee pain due to osteoarthritis. Participants were evaluated for 6 months following treatment. Evaluations included VAS score, WOMAC index, opioid and nonsteroidal anti-inflammatory drug (NSAID) use score, quality of life score, and treatment satisfaction score. At the end of 6 months, the mean VAS scores were reported to be lower. The authors reported a decrease in WOMAC scores at all evaluations following treatment. There were 18 participants who were taking opioid analgesic medications prior to radiofrequency ablation with a percentage decrease in opioid use ranging from 61.1% at month 1 to 33.3% at month 6 following radiofrequency ablation. Some participants discontinued their opioid use following radiofrequency ablation (38.9% at month 1 and 66.7% at month 6). All participants were taking NSAIDS prior to radiofrequency ablation. At the 6-month evaluation, 39.6% of participants had decreased the use of NSAIDS and 56.3% discontinued the use of NSAIDS. Quality of life was reported to be better following radiofrequency ablation by 79.1% after 1 month and 79.1% after 6 months and treatment satisfaction scores were reported as high. The study is limited by the retrospective design, small group size, and lack of a control group. There is no explanation of how the records were selected for review which raises concern about selection bias. The authors also note “further longer-term randomized, controlled, double-blind studies with larger patient series are required to substantiate these findings.”

Chen and colleagues (2020a) reported the 6-month results of an industry-sponsored randomized, multicenter study comparing cooled radiofrequency ablation of the genicular nerve to a single injection of intra-articular hyaluronic acid. All participants underwent genicular nerve blocks. Pain was assessed using the 11-point Numeric Rating Scale (NRS). The radiofrequency ablation group had a mean NRS pain score at baseline of 6.5 and 0.6 following the block. The intra-articular group had a mean NRS pain score of 6.5 at baseline and 0.5 after the block. Following the blocks, those who experienced greater than or equal to 50% reduction in pain within 15 minutes after the block were then randomized to either cooled radiofrequency ablation group (n = 88) or single intra-articular injection group (n = 87). Primary endpoint was the proportion of individuals who had knee pain reduced by greater than or equal to 50% from baseline to 6 months following treatment. Pain was again assessed using the NRS, knee pain, function, and stiffness was assessed by WOMAC. Treatment effect was assessed by GPE and the EuroQol-5 Dimensions-5 Level (EQ-5D-5L) questionnaire. At the 6-month evaluation, 76 participants in the cooled radiofrequency ablation group and 82 in the intra-articular injection group were available for evaluation. The authors report a mean NRS score reduction of 4.1 in the cooled radiofrequency group with 71% of participants reporting greater than or equal to 50% reduction in pain. In the intra-articular injection group, mean NRS score reduction was 2.5 with 38% of participants reporting greater than or equal to 50% reduction in pain. Mean WOMAC score at baseline in the cooled radiofrequency ablation group was 66.1 and 67.7 in the injection group. At the 6-month evaluation, mean WOMAC score in the cooled radiofrequency ablation group was 33.6 and 53.6 in the injection group. In terms of GPE, 1 month after treatment, the cooled radiofrequency group had 18 participants with ‘not improved’ or ‘worse’ condition and 69 participants who ‘felt improvement’ compared to 32 and 52 in the intra-articular injection group, respectively. At the 6-month evaluation, the cooled radiofrequency group had 21 participants with ‘not improved’ or ‘worse’ condition and 55 participants who ‘felt improved.’ The intra-articular group 49 participants with ‘not improved’ or ‘worse’ condition and 33 participants who ‘felt improvement.’ The mean EQ-5D-5L Index score at baseline in the cooled radiofrequency group was 0.67 and 0.80 at 6 months following treatment. Mean baseline score in the intra-articular injection group was 0.66 and 0.72 after 6 months. Overall, there were 94 adverse events in the cooled radiofrequency group and 63 in the intra-articular injection group. The cooled radiofrequency group had 18 adverse events deemed to have a relationship to treatment compared to 9 adverse events in the intra-articular injection cohort. This study has several limitations including potential for bias with the open-label design and lack of blinding. There were also only 8 participants in the cooled radiofrequency ablation group and 7 in the intra-articular group who reported taking opioid medication at baseline. With such low numbers, the authors reported difficulty measuring trends regarding opioid consumption following treatment. This study took place across several medical centers with a lack of balance across the enrolling sites. There is also a potential conflict of interest in this industry-sponsored study. Further well-designed, randomized controlled trials with larger group sizes are necessary to fully ascertain effectiveness of cooled radiofrequency ablation.

Using the same cohort in the 2020a Chen study above, Chen and colleagues (2020b) reported on participants in the intra-articular injection group who, after 6 months, were invited to “crossover” to receive cooled radiofrequency ablation treatment. These participants were then followed for an additional 6 months. The original cooled radiofrequency group was also evaluated after the additional 6 months. At the 12-month mark (from the original study start date), 66 participants from the cooled radiofrequency group were available for evaluation. In the original intra-articular injection group, 68 participants chose to crossover and receive cooled radiofrequency ablation. There were 62 participants available for evaluation at 12 months. A total of 14 participants who received intra-articular injection did not crossover and 11 were available for evaluation at 12 months. In the original cooled radiofrequency group, 43/66 participants reported pain reduction greater than or equal to 50% using the NRS pain scale. The mean NRS pain score was 2.8 at 12 months compared to the mean baseline score of 6.9. Mean total WOMAC score at 12 months was 33.2. Using GPE, 63.3% of participants reported improved knee condition. The mean EQ-5D-5L Index score was 0.81 compared to a mean baseline of 0.67. There were 47 adverse events reported and all were deemed unrelated or unlikely related to treatment. In the crossover group, 40/62 participants reported greater than or equal to 50% reduction in pain. The mean NRS score was 5.1 in this crossover group prior to receiving the cooled radiofrequency ablation. At 6 months after receiving cooled radiofrequency ablation, the mean NRS score was 3.0. Mean total WOMAC score at 12-months was 38.4. Using GPE, 62.9% reported improved knee condition. The mean EQ-5D-5L Index score was 0.79 compared to the mean baseline of 0.65. There were 68 adverse events with 62 unrelated to the treatment, 1 was unlikely related, 2 were possibly related, and 3 were probably related to treatment. Of the 11 participants in the original intra-articular injection group available at the 12-month evaluation, 10 reported greater than or equal to 50% reduction in pain. The mean NRS score at baseline was 6.9 and 1.5 at 12 months. There were 8 adverse events reported and all were deemed unrelated or unlikely related to treatment. While this study suggests individuals who initially receive intra-articular injections can benefit from cooled radiofrequency ablation afterwards, there remains a lack of well-designed randomized trials with a control group, lack of bias and conflict of interest. It should be noted that specialty medical societies do not recommend the use of intra-articular steroid injections due to uncertain efficacy.

At this time published studies lack control groups, have small group sizes, or have serious methodologic problems that prevent the drawing of treatment-guiding conclusions from their results.

References

  1. Chen AF, Khalouf F, Zora K, et al. Cooled radiofrequency ablation compared with a single injection of hyaluronic acid for chronic knee pain: a multicenter, randomized clinical trial demonstrating greater efficacy and equivalent safety for cooled radiofrequency ablation. J Bone Joint Surg Am. 2020a; 102(17):1501-1510.
  2. Chen AF, Khalouf F, Zora K, et al. Cooled radiofrequency ablation provides extended clinical utility in the management of knee osteoarthritis: 12-month results from a prospective, multi-center, randomized, cross-over trial comparing cooled radiofrequency ablation to a single hyaluronic acid injection. BMC Musculoskelet Disord. Jun 09 2020b; 21(1): 363.
  3. Choi WJ, Hwang SJ, Song JG, et al. Radiofrequency treatment relieves chronic knee osteoarthritis pain: a double-blind randomized controlled trial. Pain. 2011; 152(3):481-487.
  4. Davis T, Loudermilk E, DePalma M et al. Prospective, multicenter, randomized, crossover clinical trial comparing the safety and effectiveness of cooled radiofrequency ablation with corticosteroid injection in the management of knee pain from osteoarthritis. Reg Anesth Pain Med. 2018; 43(1):84-91.
  5. Davis T, Loudermilk E, DePalma M, et al. Twelve-month analgesia and rescue, by cooled radiofrequency ablation treatment of osteoarthritic knee pain: results from a prospective, multicenter, randomized, cross-over trial. Reg Anesth Pain Med. 2019; 44:499-506.
  6. Gupta A, Huettner DP, Dukewich M. Comparative effectiveness review of cooled versus pulsed radiofrequency ablation for the treatment of knee osteoarthritis: a systematic review. Pain Physician. 2017; 20(3):155-171.
  7. Hunter C, Davis T, Loudermilk E, et al. Cooled radiofrequency ablation treatment of the genicular nerves in the treatment of osteoarthritic knee pain: 18- and 24-month results. Pain Pract. 2020; 20(3):238-246.
  8. Iannaccone F, Dixon S, Kaufman A. A review of long-term pain relief after genicular nerve radiofrequency ablation in chronic knee osteoarthritis. Pain Physician. 2017; 20(3):E437-E444.
  9. Kapural L, Lee N, Neal K, Burchell M. Long-term retrospective assessment of clinical efficacy of radiofrequency ablation of the knee using a cooled radiofrequency system. Pain Physician. 2019; 22(5):489-494.
  10. Konya ZY, Akin Takmaz S, Başar H, et al. Results of genicular nerve ablation by radiofrequency in osteoarthritis-related chronic refractory knee pain. Turk J Med Sci. 2020; 50(1):86-95.
  11. McCormick ZL, Korn M, Reddy R, et al. Cooled radiofrequency ablation of the genicular nerves for chronic pain due to knee osteoarthritis: six-month outcomes. Pain Med. 2017; 18(9):1631-1641.
  12. Protzman NM, Gyi J, Malhotra AD, Kooch JE. Examining the feasibility of radiofrequency treatment for chronic knee pain after total knee arthroplasty. PM R. 2014; 6(4):373-376.
  13. Qudsi-Sinclair S, Borrás-Rubio E, Abellan-Guillén JF, et al. A comparison of genicular nerve treatment using either radiofrequency or analgesic block with corticosteroid for pain after a total knee arthroplasty: a double-blind, randomized clinical study. Pain Pract. 2017; 17(5):578-588.
  14. Santana Pineda MM, Vanlinthout LE, Moreno Martín A, et al. Analgesic effect and functional improvement caused by radiofrequency treatment of genicular nerves in patients with advanced osteoarthritis of the knee until 1 year following treatment. Reg Anesth Pain Med. 2017; 42(1):62-68.
  15. Yilmaz V, Umay E, Gundogdu I, Aras B. The comparison of efficacy of single intraarticular steroid injection versus the combination of genicular nerve block and intraarticular steroid injection in patients with knee osteoarthritis: a randomised study. Musculoskelet Surg. 2019 Dec 11. Online ahead of print.
  16. American Academy of Orthopaedic Surgeons. Osteoarthritis. Available at: http://orthoinfo.aaos.org/topic.cfm?topic=a00227. Accessed on October 5, 2020.
  17. American College of Rheumatology. Osteoarthritis. Available at: http://www.rheumatology.org/I-Am-A/Patient-Caregiver/Diseases-Conditions/Osteoarthritis. Accessed on October 5, 2020.
  18. Centers for Disease Control. Osteoarthritis. Available at: http://www.CDC.gov/arthritis/osteoarthritis.htm. Accessed on October 5, 2020.

Coding Section 

Code Number Description
CPT  64450  Injection, anesthetic agent; other peripheral nerve or branch (when specified as genicular nerve block)
  64454 (effective 01/01/2020) genicular nerve branches, including imaging guidance, when performed 
  64624 (effective 01/01/2020) Destruction by neurolytic agent, genicular nerve branches including imaging guidance, when performed 
  64640  Destruction by neurolytic agent; other peripheral nerve or branch ([when specified as ablation of genicular nerve(s))
  64999  Unlisted procedure, nervous system (when specified as cooled or pulsed RF therapy (not destruction) to genicular nerve(s)) 
ICD-10 DIAGNOSIS  M08.861-M08.869  Other juvenile arthritis, knee 
  M08.961-M08.969  Juvenile arthritis, unspecified, knee 
  M12.561-M12.569  Traumatic arthropathy, knee 
  M12.861-M12.869  Other specific arthropathies, not elsewhere classified, knee 
  M13.161-M13.169  Monoarthritis, not elsewhere classified, knee 
  M13.861-M13.869  Other specified arthritis, knee 
  M17.0-M17.9  Osteoarthritis of knee 
  M21.061-M21.069  Valgus deformity, not elsewhere classified, knee 
  M21.161-M21.169  Varus deformity, not elsewhere classified, knee 
  M21.261-M21.269  Flexion deformity, knee 
  M22.00-M22.92  Disorder of patella 
  M23.000-M23.92  Internal derangement of knee 
  M24.361-M24.369  Pathological dislocation of knee, not elsewhere classified 
  M24.461-M24.469  Recurrent dislocation, knee 
  M24.561-M24.569  Contracture, knee 
  M24.661-M24.669  Ankylosis, knee
  M25.361-M25.369  Other instability, knee 
  M25.561-M25.569  Pain in knee 
  M25.661-M25.669  Stiffness of knee, not elsewhere classified 
  M25.761-M25.769  Osteophyte, knee 
  M25.861-M25.869  Other specified joint disorders, knee 
  M66.0  Rupture of popliteal cyst 
  M67.361-M67.369  Transient synovitis, knee 
  M67.461-M67.469  Ganglion, knee 
  M67.50-M67.52  Plica syndrome 
  M67.861-M67.869  Other specified disorders of synovium and tendon, knee 
  M70.40-M70.42  Prepatellar bursitis 
  M70.50-M70.52  Other bursitis of knee 
  M71.20-M71.22  Synovial cyst of popliteal space 
  M71.561-M71.569  Other bursitis, not elsewhere classified, knee 
  M92.40-M92.42  Juvenile osteochondrosis of patella 
  M92.50-M92.52  Juvenile osteochondrosis of tibia and fibula 
  M94.261-M94.269  Chondromalacia, knee 
  S80.00XA-S80.02XS  Contusion of knee 
  S83.101A-S83.196S  Subluxation and dislocation of knee 
  S83.401A-S83.92XS  Sprain of knee 
  S87.00XA-S87.02XS  Crushing injury of knee 
  T84.84XA-T84.84XS  Pain due to internal orthopedic prosthetic devices, implants and grafts 
  Z96.651-Z96.659  Presence of artificial knee joint

Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each policy. They may not be all-inclusive. 

This medical policy was developed through consideration of peer-reviewed medical literature generally recognized by the relevant medical community, U.S. FDA approval status, nationally accepted standards of medical practice and accepted standards of medical practice in this community, Blue Cross Blue Shield Association technology assessment program (TEC) and other nonaffiliated technology evaluation centers, reference to federal regulations, other plan medical policies, and accredited national guidelines.

"Current Procedural Terminology © American Medical Association. All Rights Reserved" 

History From 2019 Forward     

08/02/2023 Annual review, no change to policy intent.
08/23/2022 Annual review, no change to policy intent. 

08/02/2021 

Annual review, no change to policy intent. Updating rationale and references. 

08/04/2020 

Annual review, no change to policy intent. 

12/13/2019 

Added codes '64454' and '64624'

08//28/2019

New Policy

Complementary Content
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