If you're having surgery on your leg, you may be given a femoral nerve block. It's an injection
To start, you lie down. Your skin is numbed. Then, the doctor finds your femoral nerve. That's a large nerve in your hip and thigh. The doctor may use electric stimulation to help find the nerve. Or, the doctor may use ultrasound. When the nerve has been found, a needle is carefully pushed through your numbed skin and down to the nerve. Medicine is injected to bathe the nerve. It blocks sensation in your thigh and in your knee. The numbness lasts for several hours. You may be given other medicine to keep your pain under control when the block wears off.