Which of the following supplies is part of the standard set-up for a diagnostic knee arthroscopy?

In a diagnostic knee arthroscopy, inflow tubing is crucial as it is used to deliver fluid into the joint space. This is essential for creating a clear view of the anatomy within the knee during the procedure. The fluid helps to distend the joint and provides better visibility for the surgeon to inspect and possibly treat any identified issues, such as tearing or damage to cartilage or ligaments.

The other options, while they may have specific applications in surgery, are not standard components for a diagnostic knee arthroscopy setup. For example, the Poole suction tip is typically used in procedures where large volumes of fluids are present, such as abdominal surgeries, rather than a targeted, minimally invasive procedure like knee arthroscopy. The #20 blade is generally used for larger incisions and is not standard for the smaller entry points utilized in knee arthroscopy. A 3000 mL bag of glycine could be used as a distending medium, but it is not a standard supply required for every diagnostic knee arthroscopy, as various irrigation solutions can be used depending on the surgeon's preference. Thus, inflow tubing stands out as an essential and standard component of the setup for a diagnostic knee arthroscopy.