Regional Anesthestic Techniques

FEMORAL NERVE BLOCK

The femoral nerve block is a regional anesthetic technique used in conjunction with general anesthesia for ACL reconstruction surgery. It is a safe and effective block that provides both safe and excellent surgical anesthesia and post-operative pain control.

During a preoperative phone interview the procedure and its risks and benefits will be discussed with you. On arrival to the ASC prep area you will be asked to sign a consent for the procedure. You will then be attached to the usual monitors: a blood pressure cuff, a light sensor to measure your blood oxygen level will be attached to your finger, and EKG leads will be placed on your chest. You will receive some sedation through your intravenous prior to placement of the block, which both relaxes you and will likely cause you to have little or no recollection of the block placement.

Next, the anesthesiologist will cleanse your groin region on the operative side with an antiseptic solution. He or she will use both anatomical landmarks and an ultrasound machine to find the desired location for the block in the groin region.

Once the optimum location is found, the anesthesiologist will numb the skin with some local anesthetic. Next he or she will slowly insert a needle as thin as a paper clip into that location. Your anesthesiologist will utilize the ultrasound to guide the needle to a location near the nerve. Occasionally, a very small amount of electrical current will be put through the needle as the needle is advanced to assist in locating the nerves to your thigh and knee and optimizing the needle placement. You will feel the sensation of involuntary twitches or movements in your upper leg and kneecap. Don't try to stop these movements because they tell us if we are in the right location with the needle. When the location and/or response is optimal the anesthesiologist will inject the long acting Novocain like medicine to numb the front of your thigh and knee. This procedure usually takes only a few minutes to perform.

The block takes approximately 15-20 minutes to work. You will notice upper leg weakness and numbness. Once in the operating room, you will once again be attached to the usual monitors and positioned by the surgeon. You will receive a light general anesthetic in addition to the femoral nerve block as your anesthetic because the femoral nerve block doesn't numb up the back of the knee.

After the surgery and transport to the recovery room the general anesthesia will begin to wear off. You will have little or no pain in the front of your leg or knee. However you will probably have some discomfort behind your knee. That is expected. You will receive pain medicine in the recovery room, as you need it.

The numbness and weakness from the block usually lasts from 8-20 hrs and occasionally greater than 24 hrs. As it begins to wear off you should start your pain medicine that was prescribed by the surgeon.