Chemical Neurolysis of the Genicular Nerves for Chronic Knee Pain: Reviving an Old Dog and an Old Trick

Dear Editor, Image-guided genicular nerve radiofrequency neurolysis (RFN) has emerged as a novel method to treat knee pain from primary osteoarthritis (OA) and chronic knee pain following total knee replacement surgery (TKR), with decreased pain and improved function in the majority of properly selected patients [1,2]. Despite the precision, reliability, safety, and clinical effectiveness of RFN, downsides of genicular nerve RFN are known: procedure and equipment costs, relatively low reimbursements, procedure-related pain often necessitating twilight anesthesia, and a nonresponse rate over 25% [2,3]. We have found that image-guided chemical neurolysis (ChN) with alcohol or phenol compounds is a cost-effective alternative to RFN for primary knee pain from OA and also as a salvage technique when RFN fails. Table 1 summarizes four cases from our respective clinical practices in which image-guided genicular nerve ChN successfully treated chronic knee pain. Despite variability in patient age, health status, severity of knee joint degeneration, and pre- vs post-TKR status, all patients experienced profound durable pain reduction and improved function following ChN, ranging from five to 12 months of profound pain relief and improved knee function. Further, we found ChN to be safe in a chronically anticoagulated patient who could not safely discontinue anticoagulant use. We have seen no adverse events in any of these cases, and no case of dysesthesia, deafferentation pain, or chemical skin burns.