Should You Get Knee Nerve Ablation?

Medically Reviewed By:

Dr. Chaz Fausel, MD

Dr. Chaz Fausel is a Denver-based interventional orthopedics specialist and Regenexx educator, trained at Emory and the Centeno-Schultz Clinic.

Nerve ablation knee treatment is a procedure that has gained attention in recent years for addressing knee pain. This page will provide an overview of the procedure, its potential risks, and alternative options.

Nerve Ablation And Its Potential Role In Addressing Knee Pain

Nerve ablation—particularly radiofrequency ablation (RFA)— is commonly considered for management of knee pain associated with moderate to severe osteoarthritis. This procedure is typically offered to individuals who may be candidates for knee replacement but are seeking non-surgical alternatives. It is also offered to individuals with advanced arthritis who are not candidates for knee replacement due to their medical history. For mild arthritis, other non-surgical approaches may be more appropriate, as determined by a physician’s evaluation.

How Nerve Ablation May Affect Knee Pain

The knee contains geniculate nerves that surround the joint and transmit pain signals. Nerve ablation procedures are designed to interrupt these signals by targeting specific nerve pathways involved in pain transmission. This approach may help reduce knee pain in some individuals^[1].

What Are The Different Types of RFA Procedures?

Radiofrequency ablation (RFA) procedures are used to interrupt pain signal transmission from targeted nerves. There are two main types: “cooled RFA,” and pulsed RFA (PRF).

Cooled RFA

Cooled RFA involves the use of a probe that delivers heat via electrical current. Although the probe is cooled internally, the purpose is to maintain a consistent temperature at the targeted nerve tissue. This technique aims to create a larger treatment area and can result in a more extensive nerve signal disruption.

Pulsed RFA (PRF)

Pulsed RFA (PRF), in contrast, uses short bursts of electrical energy and does not produce the same level of heat. This approach is designed to modulate nerve activity without causing the same level of thermal impact^[14].

Some studies suggest PRF may result in less surrounding tissue impact; however, a review of smaller studies found no significant difference in reported outcomes between cooled and pulsed RFA procedures^[10].

Is Nerve Ablation A Viable Option?

Preliminary research, largely based on small studies ^[5,10], suggests that nerve ablation may help reduce pain in certain cases. However, no large-scale or high-level studies are currently available, and further research is needed to better understand the potential benefits and limitations of this approach.

Timeline for Potential Pain Reduction Following the Procedure

The onset of pain reduction following nerve ablation may vary, with effects observed anywhere from immediately to several weeks after the procedure. On average, noticeable improvement has been reported around 10 days post-procedure. In cooled RFA, the delay may be related to the time required for the thermal effects to fully disrupt nerve signal transmission and for post-procedural inflammation to resolve.

Duration of Reported Effects from Nerve Ablation

Reported pain reduction following nerve ablation may last approximately six months, though in some cases it may persist for up to a year. In one study, 88% of individuals reported noticeable pain reduction at three months, which declined to 64% by six months and approximately one-third by one year ^[11]. These outcomes may vary based on individual factors and the type of RFA used.

The Role of a Diagnostic Block in Nerve Ablation

A diagnostic block involves numbing the targeted nerves prior to a nerve ablation procedure to help assess whether temporary pain reduction is possible. If short-term improvement occurs following the injection, this may indicate that the individual could benefit from further treatment.

Research on the use of diagnostic blocks before nerve ablation is mixed. One small study found no significant difference in outcomes for individuals with knee arthritis who received a diagnostic block beforehand ^[6]. However, a 2017 study reported that only 19% of individuals experienced meaningful pain reduction when a diagnostic block was not performed before treatment [9]. Based on available data, a diagnostic block may help guide treatment decisions, and this option can be discussed with a qualified physician.

Imaging Techniques Used To Guide RFA Probe Placement

Either fluoroscopy (real-time X-ray) or ultrasound may be used to guide radiofrequency ablation (RFA) procedures. Fluoroscopy enables visualization of bony landmarks, which are used to estimate the nerve pathway and guide probe placement accordingly. While fluoroscopy does not directly visualize nerves, it allows for consistent placement based on anatomical reference points.

Ultrasound, by contrast, enables direct visualization of soft tissue structures, including the nerve, allowing for probe placement across the targeted nerve pathway. However, a recent study reported no significant difference in outcomes between ultrasound-guided and fluoroscopy-guided RFA procedures ^[10].

Are There Side Effects To Consider?

The most common side effect is numbness, tingling, or burning over the skin of the knee, which is due to the destruction of the nerve. Other side effects include infection, damage to the overlying tendons, and skin burns ^[3,4,7].

However, while rare, damage to the blood vessels can occur as well.The nerve travels alongside the artery and vein, and ablating the nerve carries a risk of damaging these blood vessels. These adverse vascular events are documented in the literature, with 27 cases being reported to date. The most common of these events included the formation of a pseudoaneurysm (a collection of blood outside an artery), an abnormal connection between the artery and vein (arteriovenous fistula), bleeding into the joint (hemarthrosis), and/or death of the knee cap bone (osteonecrosis of the patella) ^[13].

Concerns Surrounding Cooled RF Procedure

While the term “cooled RFA” may seem counterintuitive, the probe is cooled to manage the high temperatures generated during the procedure. Some experts have raised concerns that the high energy used in these procedures could result in additional tissue damage ^[8].

It is also worth noting one study that found no significant difference in outcomes between a local anesthetic with a steroid injection near the nerves and a cooled RFA procedure ^[12]. This suggests that a nerve block with anesthetic achieved similar effects to nerve ablation in that particular study.

Knee Conditions Managed With Nerve Ablation

Alternative Treatment Options To Consider

For individuals seeking to address the underlying condition causing knee pain, rather than only the pain signals, other non-surgical approaches are available. Orthobiologic procedures using Regenexx injectates, such as platelet-rich plasma (PRP) and bone marrow concentrate, as a non-surgical option for individuals with knee arthritis ^[15-18]. The goal of these procedures is to support the body’s natural healing response.

While nerve ablation procedures may help reduce pain by disrupting nerve signals, this process uses thermal energy and may result in nerve damage. It is important for a patient to discuss the potential risks and complications of any medical intervention with a qualified physician.

References

1. Kidd VD, Strum SR, Strum DS, Shah J. Genicular Nerve Radiofrequency Ablation for Painful Knee Arthritis: The Why and the How. JBJS Essent Surg Tech. 2019;9(1):e10. Published 2019 Mar 13. doi:10.2106/JBJS.ST.18.00016
2. Kim DH, Lee MS, Lee S, Yoon SH, Shin JW, Choi SS. A Prospective Randomized Comparison of the Efficacy of Ultrasound- vs Fluoroscopy-Guided Genicular Nerve Block for Chronic Knee Osteoarthritis. Pain Physician. 2019;22(2):139-146. https://pubmed.ncbi.nlm.nih.gov/30921977/
3. Conger A, McCormick ZL, Henrie AM. Pes Anserine Tendon Injury Resulting from Cooled Radiofrequency Ablation of the Inferior Medial Genicular Nerve. PM R. 2019;11(11):1244-1247. doi:10.1002/pmrj.12155
4. Khanna A, Knox N, Sekhri N. Septic Arthritis Following Radiofrequency Ablation of the Genicular Nerves. Pain Med. 2019;20(7):1454-1456. doi:10.1093/pm/pny308
5. El-Hakeim EH, Elawamy A, Kamel EZ, et al. Fluoroscopic Guided Radiofrequency of Genicular Nerves for Pain Alleviation in Chronic Knee Osteoarthritis: A Single-Blind Randomized Controlled Trial. Pain Physician. 2018;21(2):169-177. https://pubmed.ncbi.nlm.nih.gov/29565947/
6. McCormick ZL, Reddy R, Korn M, et al. A Prospective Randomized Trial of Prognostic Genicular Nerve Blocks to Determine the Predictive Value for the Outcome of Cooled Radiofrequency Ablation for Chronic Knee Pain Due to Osteoarthritis. Pain Med. 2018;19(8):1628-1638. doi:10.1093/pm/pnx286
7. McCormick ZL, Walega DR. Third-Degree Skin Burn from Conventional Radiofrequency Ablation of the Inferiomedial Genicular Nerve. Pain Med. 2018;19(5):1095-1097. doi:10.1093/pm/pnx204
8. Sluijter ME, Teixeira A. Cooled Radiofrequency Ablation of Genicular Nerves for Knee Osteoarthritis Pain: A Letter to Editor. Anesth Pain Med. 2017;7(3):e46940. Published 2017 Apr 8. doi:10.5812/aapm.46940
9. McCormick ZL, Korn M, Reddy R, Marcolina A, Dayanim D, Mattie R, Cushman D, Bhave M, McCarthy RJ, Khan D, Nagpal G, Walega DR. Cooled Radiofrequency Ablation of the Genicular Nerves for Chronic Pain due to Knee Osteoarthritis: Six-Month Outcomes. Pain Med. 2017 Sep 1;18(9):1631-1641. doi: 10.1093/pm/pnx069
10. 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. https://pubmed.ncbi.nlm.nih.gov/28339430/
11. Santana Pineda MM, Vanlinthout LE, Moreno Martín A, van Zundert J, Rodriguez Huertas F, Novalbos Ruiz JP. 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. doi:10.1097/AAP.0000000000000510
12. Qudsi-Sinclair S, Borrás-Rubio E, Abellan-Guillén JF, Padilla Del Rey ML, Ruiz-Merino G. 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. doi:10.1111/papr.12481
13. Kim SY, Le PU, Kosharskyy B, Kaye AD, Shaparin N, Downie SA. Is Genicular Nerve Radiofrequency Ablation Safe? A Literature Review and Anatomical Study. Pain Physician. 2016;19(5):E697-E705. https://pubmed.ncbi.nlm.nih.gov/27389113/
14. Facchini G, Spinnato P, Guglielmi G, Albisinni U, Bazzocchi A. A comprehensive review of pulsed radiofrequency in the treatment of pain associated with different spinal conditions. Br J Radiol. 2017;90(1073):20150406. doi:10.1259/bjr.20150406
15. Xing D, Wang B, Zhang W, et al. Intra-articular platelet-rich plasma injections for knee osteoarthritis: An overview of systematic reviews and risk of bias considerations. Int J Rheum Dis. 2017;20(11):1612-1630. doi:10.1111/1756-185X.13233
16. Filardo G, Kon E, Buda R, et al. Platelet-rich plasma intra-articular knee injections for the treatment of degenerative cartilage lesions and osteoarthritis. Knee Surg Sports Traumatol Arthrosc. 2011;19(4):528-535. doi:10.1007/s00167-010-1238-6
17. Southworth TM, Naveen NB, Tauro TM, Leong NL, Cole BJ. The Use of Platelet-Rich Plasma in Symptomatic Knee Osteoarthritis. J Knee Surg. 2019;32(1):37-45. doi:10.1055/s-0038-1675170
18. Centeno C, Sheinkop M, Dodson E, et al. A specific protocol of autologous bone marrow concentrate and platelet products versus exercise therapy for symptomatic knee osteoarthritis: a randomized controlled trial with 2 year follow-up. J Transl Med. 2018;16(1):355. Published 2018 Dec 13. doi:10.1186/s12967-018-1736-8

Medically Reviewed By:

Dr. Chaz Fausel, MD

Dr. Chaz Fausel is a Denver-based interventional orthopedics specialist and Regenexx educator, trained at Emory and the Centeno-Schultz Clinic.