Because the arthroscope and surgical instruments are thin, your surgeon can use very small incisions, rather than the larger incision needed for open surgery. This results in less pain for patients, less joint stiffness, and often shortens the time it takes to recover and return to favorite activities. During arthroscopy, your surgeon can see the structures of your knee in great detail on a video monitor.
For a function of three variables, a level set is a surface in three-dimensional space that we will call a level surface. For a constant value $c$ in the range of $f(x,y,z)$, the level surface of $f$ is the implicit surface given by the graph of $c=f(x,y,z)$.
set. 1. to put (something or someone) in a particular place, position, or posture: to set a vase on a table; Set the baby on her feet. 2. to put or cause to pass into some condition: to set a house on fire; to set a prisoner free. 3. to put or apply: to set fire to a house. 4. to fix definitely; establish or decide upon: to set a time limit; to set a wedding date. 5. to put (a price or value) upon something. 6. to fix the value of at a certain amount, rate, or point: She sets honesty above everything else.