Is misctomy and arthoscopy same.? What is the difference?

A type of scope. An meniscectomy is a type of arthroscopic surgery of the knee. In fact, it is the most common type of arthroscopy. During the surgery, damaged meniscus is removed from the knee: http://abt.Cm/1j1bxcz.
No. Arthroscopy is a technique for looking into a joint with a tube that contains an optic system for a camera and a light . It allows a surgeon to see and fix things in a joint 9commonly the knee or shoulder) without making a larger cut to do so. By "misctomy" i assume what you meant was "meniscectomy". That is to remove part or all of the knee's meniscus with can be done arthroscopically.
No. Arthroscopy is an orthopedic surgery where a small 'scope' w/ camera is placed into a joint to visualize structures and perform procedures(knee, shoulder , elbow , ankle, wrist, hip etc.)meniscectomy involves removing a torn piece of cartilage ( arthroscopically) from the knee joint. Meniscus='cushion' cartilage in knee . Hope this is clear!