Novel use of genicular and vastus intermedius blocks for refractory knee pain in sickle cell disease

To Editor, We wish to report the successful use of ultrasound-guided bilateral genicular nerve block (GNB) augmented by vastus intermedius nerve block for refractory knee pain in a young adult with sickle cell disease (SCD). A 22-year-old male with homozygous SCD presented to our emergency department (ED) with excruciating bilateral knee pain, rated 9/10 on the Numerical Rating Scale (NRS). He denied recent trauma and reported two vaso-occlusive crises over the preceding 2 years, managed conservatively with hydration and opioids. Despite receiving intravenous paracetamol 1 g and fentanyl 100 µg, his pain persisted unabated, severely limiting any mobilization or physical therapy. He was referred to our ED after administration of several pain medications, none of which produced meaningful improvement. Given the severity and refractory nature of his knee pain, we planned a bilateral GNB under ultrasound guidance as the targeted, opioid-sparing intervention. After informed consent, the patient was positioned supine with slight knee flexion. A high-frequency linear probe (SonoSite EDGE II; SonoSite, Inc. Bothell, WA, USA) identified the superomedial, superolateral, and inferomedial genicular nerves adjacent to the femoral condyles. Under strict asepsis, a 22-gauge, 50 mm echogenic needle was advanced in-plane to each genicular branch. We injected 3 mL of 0.2% ropivacaine per site on each side. To enhance analgesia in the anterior knee compartment innervated by the vastus intermedius nerve, an additional 3 mL of 0.2% ropivacaine was deposited lateral to the femoral shaft just above the adductor canal on each limb. Fifteen minutes after block completion, the patient’s NRS decreased to 6/10. At one-hour post-procedure, he reported dramatic relief, with his NRS score falling to 1/10. He experienced complete pain relief (0/10) within two hours and was able to perform gentle quadriceps contractions and passive knee flexion without discomfort. He remained pain-free for eighteen hours post-block, enabling transition from intravenous to oral analgesics and subsequent transfer to the inpatient ward with an NRS of 0/10. Peripheral nerve blocks were reported for managing acute pain in sickle cell crises affecting the extremities, yet GNB for isolated knee pain in this population is scarcely documented.[1–3] Genicular nerves transmit nociceptive signals from the osteoarticular, periosteal, and synovial components of the knee, making them attractive targets for sustained analgesia without the systemic side effects of high-dose opioids or nonsteroidal anti-inflammatory drugs.[4] The addition of a vastus intermedius block addresses the motor branch contributions to anterior knee pain, yielding comprehensive regional anesthesia of the knee joint.[4] This case demonstrates that combined genicular and vastus intermedius nerve blocks can provide rapid, profound, and prolonged analgesia in sickle cell patients with refractory knee pain. Ultrasound guidance ensures precise local anesthetic deposition and minimizes complications.[1] Adoption of this technique may reduce opioid consumption, facilitate early mobilization, and improve patient satisfaction during vaso-occlusive crises with predominant knee involvement.[5] Further prospective studies to compare GNB against standard analgesic protocols in SCD and to establish optimal dosing regimens could refine multimodal pain management strategies and potentially mitigate the burden of opioid use in this vulnerable population. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understand that name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.