Arthrogram techniques, contrast agents, and injectates will differ at different institutions. 

Before commencing these procedures, it is important to familiarise local practices, in particular to syringe selection. Many of the used solutions are clear, therefore the different syringes will help the practitioner identify which syringe contains which agent. Using the same type for each procedure will minimize confusion in cases when there are interruptions. 

The syringe selection, in this case, is as follows

• 5 mL syringe for 1% lidocaine and attached to a 25G needle
• 10 mL for contrast agent and attached to extension tubing
• 20 mL syringe for the arthrogram injectate

Attaching the syringe and needle will help further identify the injectates. The contrast will come in different osmolalities, the one used in this study is iohexol 300. The arthrogram mixture used in this case is 0.1 mL gadobutrol, 9.9mL 0.9% saline, 5 mL iohexol 300, and 5 mL 0.5% ropivacaine; 10mL of the arthrogram solution was injected in total. The small amount of 0.5% ropivacaine is an important diagnostic component of the injectate. If the patient experiences pain relief after the procedure for the duration of the ropivacaine (7-8 hours), it is deemed the injected joint is the pain generator.