From the Guidelines
Genicular nerve blocks can be a valuable addition to a multimodal pain management approach prior to knee replacement surgery, as they have been shown to reduce pain and opioid requirements in the postoperative period. These blocks involve injecting local anesthetic around the superior lateral, superior medial, and inferior medial genicular nerves that supply sensation to the knee joint. The procedure is typically performed under ultrasound guidance to ensure accurate placement. When administered preoperatively, genicular nerve blocks can reduce pain during the immediate postoperative period, potentially decreasing opioid requirements and facilitating earlier mobilization. The blocks generally last 12-24 hours depending on the anesthetic used, though adding adjuvants like dexamethasone may extend this duration. For implementation, the procedure should be performed by an anesthesiologist or pain specialist shortly before surgery.
- Key benefits of genicular nerve blocks include:
- Reduced pain in the immediate postoperative period
- Decreased opioid requirements
- Facilitated earlier mobilization
- Targeted analgesia without causing motor weakness or affecting other sensations in the leg
- The most recent and highest quality study, 1, recommends a primary neuraxial anaesthetic technique for total knee arthroplasty (TKA), given several positive benefits on important post-TKA outcomes, but does not specifically address genicular nerve blocks. However, the study highlights the importance of multimodal pain management approaches, which can include genicular nerve blocks.
- While the evidence from 1 and 1 is older and focused on postoperative analgesia, it still supports the use of regional anaesthesia techniques, including femoral nerve blocks, for pain management after TKA.
- In real-life clinical practice, the decision to use genicular nerve blocks prior to knee replacement surgery should be made on a case-by-case basis, taking into account the individual patient's needs and medical history, as well as the availability of skilled personnel to perform the procedure.
From the Research
Genicular Nerve Blocks Prior to Knee Replacement Surgery
- Genicular nerve blocks can be used prior to knee replacement surgery as a technique to manage postoperative pain, as shown in studies 2, 3, 4, 5.
- The blocks target sensory branches from the knee capsule, reducing local anesthetic dose and providing effective analgesia in the first 24 hours following surgery 2.
- A randomized controlled trial compared the analgesic efficacy of genicular nerves block vs. local infiltration analgesia in the first 24 hours following total knee arthroplasty, finding that genicular nerves block provides non-inferior analgesia with a considerable reduction in local anesthetic dose 2.
- Another study found that genicular nerve block was associated with a reduction in opioid consumption at 24 hours in primary total knee arthroplasty patients 4.
Comparison with Other Techniques
- A study compared the efficacy of popliteal artery and the capsule of the posterior knee (IPACK) block and genicular nerve block on postoperative pain scores, finding that both blocks were effective in improving patient comfort during and after total knee replacement surgery 3.
- However, the genicular block seemed to be a promising technique that can offer improved pain management in the immediate and early postoperative period without adverse effects on systemic and motor variables 3.
Preoperative Use
- A prospective randomized sham-controlled trial found that preoperative genicular nerve radiofrequency ablation had no effect on postoperative pain outcomes following total knee arthroplasty 6.
- This suggests that the use of genicular nerve blocks prior to knee replacement surgery may be more effective when used as a postoperative pain management technique rather than a preoperative intervention 6.