The genicular nerve block (G block) is a diagnostic procedure done to ascertain if the patient may need a Genicular Nerve Ablation (RF Neurotomy) done to promote long-term pain relief. It’s a procedure done on an outpatient basis and requires the simple injection of an anesthetic into the genicular nerves which are the sensory nerves that help communicate pain signals emanating from the knee towards the brain. By anesthetizing these sensory nerves, it creates a disruption to the communication of pain signals coming from the degenerating knee, helping to promote a temporary state of pain relief.
Prior to the start of the procedure, the patient will be directed to lay down on the back for additional comfort during the procedure, and padding may be provided. The surface skin of the knee is sterilized with an antiseptic solution. The sites where the injection will take place are numbed with a small amount of local anesthetic. In the event where the patient exhibits severe pain from the joints, anesthesia or minimal sedation may be applied in order to help the patient become more comfortable and relaxed.
A fluoroscope will help to visualize on the screen the sites of the genicular nerves to be blocked and the locations will be marked on the skin. Once the locations of the genicular nerves are determined, 3 needles are inserted and a contrast dye is applied to ascertain that the needles are placed at the appropriate locations. Once their positions have been confirmed, a minute amount of anesthetic is injected, creating a blockage within the genicular nerves, thus completing the procedure.
Patients are expected to experience some slight numbness of the knee and reduced sensation as well. The patient will also expect one of two outcomes from the procedure. Either the pain is reduced for a prolonged period of time, thus confirming that the source of the pain is from the genicular nerves and a genicular nerve neurotomy should be considered, or there is no pain relief and another treatment option may need to be considered.