As spine operations go, a microdiscectomy is a fairly common, minimally invasive procedure that can be done in a short amount of time and with a nominal hospital stay. Tiger’s surgery was reportedly performed last Wednesday and he was back at home recovering by Thursday night. The procedure, also called a microdecompression, is done to reduce pressure that is being put on a spinal nerve – usually by a herniated disk. Via a small incision in the midline of the patient’s back, the surgeon uses special instruments to pull the muscles away from the bony surface that covers the affected vertebra, which is called the lamina. He next cuts away a small part of the lamina so that he can access and remove the herniated disk material that is pressing on the nerve, vacuum out any debris that’s in the spinal canal, then replace the muscles and close the incision.