The femoral nerve block is a procedure done on an outpatient basis that provides complete numbness of the legs through the use of a local anesthetic. The procedure is done either prior to or subsequent to surgery performed on the knee or thigh and serves to provide effective control over post-operative pain.
The patient will be directed to lie down, positioned properly where there is sufficient access to the groin area. The area will be first cleansed using antiseptic solution and then through either an ultrasound machine or identification of certain anatomical landmarks, the location from which the needle will be inserted into the groin is ascertained. Once the precise location has been determined, local anesthetic is then applied to numb the region. Once the numbing sensation is in full effect, a needle will then be carefully inserted into the designated location. A minute quantity of electric current may be applied in order to properly locate the desired nerve and ensure the needle is properly placed. The patient may experience periods of involuntary twitching which will help to determine if the needle is in the right location. Once the location has been reached, medication will be injected, flooding the nerves and creating numbness around the thigh and knee.
This procedure usually takes anywhere from 15 to 20 minutes to complete. In addition to the numbness, the patient may also experience slight weakness along region of the leg. The numbing sensation is expected to last for several hours, ensuring that the patient experiences no pain or other issues during the course of surgery. Once surgery has been completed, the anesthesia from the nerve block procedure will begin to wear off. The patient some slight discomfort in the area beneath the knee but little to no pain. The weakness the numbness from the block procedure usually lasts for up 24 hours and in some cases, more than 24 hours. Once it wears off, patients can commence taking pain medication prescribed to them.