Knee arthroscopy is used in the diagnosis and treatment of a number of knee disorders and injuries.  One common use is in the treatment of meniscal tears.  Under normal conditions, the menisci, the c-shaped pieces of cartilage resting between the femur and tibia provide cushioning and stability for the knee joint, injuries or arthritis can cause the menisci to become torn resulting in knee pain, swelling, and diminished range of motion.  Knee arthroscopy is often preformed to remove the damaged portion of the meniscus.  When you arrive to the hospital for your procedure, an intravenous line will be started and you may be given a sedative to help you relax.  The procedure can be performed under spinal anesthesia, which keeps you numb from the waist down.  Local anesthesia which keeps your knee area numb or less commonly general anesthesia which renders you unconscious for the duration of the procedure.  An arthroscopic meniscectomy usually takes between 45 to 90 minutes.  The surgeon will gain access to your knee joint by using sharp instruments called trocars to make two or three small openings or ports; here the surgeon will inject a sterile solution in to the joint to push the surfaces apart allowing the structures inside the joint to be viewed more easily.  Next your surgeon will insert the arthroscope and other instruments through the various ports where in the arthroscopes camera are magnified and projected on to the video monitor.  Your surgeon will carefully examine the inside of your knee joint, locate the damage, remove any loose or severely injured parts and use a shaving instrument to smooth any jagged edges, well it may be possible to repair the meniscus with small stitches.  In most cases, the damaged portion must be removed.  At the end of the procedure, your surgeon will again carefully examine the entire knee for any areas of bleeding or any other damage, remove the arthroscope and other instruments and close each of the key hole incisions with a few sutures.  After your surgery, you will be taken to the recovery area for monitoring, where you will be given pain medications as needed.  Most patients leave the outpatient surgery unit within a few hours.