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 $c=f(x,y,z)$.
A data set is a collection of information organized as a stream of bytes in logical record and block structures for use by IBM mainframe operating systems. The record format is determined by data set organization, record format and other parameters. The physical structure of each record is nearly the same, and uniform throughout a data set. This is specified in the data control block record format parameter.