Arthroscopic procedures are minimally invasive procedures in which the surgeon operates with small incisions mainly 2-3 small incisions in number, depending on the joint to be operated. They are also known as key-hole procedures / surgeries.
An arthroscope, is a pencil sized instrument with a camera lens and lighting system, that enables a surgeon to look at the interior of the joint / operable sight as a magnified image on a video monitor. This would need one incision. After diagnosing the problem, the surgeon would decide on the type / technique of surgery needed, and proceed accordingly.