MSK: Procedures

Question 1

Why is it important to avoid putting air in the joint during an arthrogram injection?

Answer 1

Air in the joint will cause susceptibility artifact

Question 2

What are the steps to a hip arthrogram injection?

Answer 2

• Mark the femoral artery
• Internally rotate the hip slightly to localize your target (the femoral head-neck junction)
• Clean and numb the skin
• Advance needle straight down on the superior aspect of the head-neck junction
• Inject a small amount of contrast to confirm position (contrast should flow away from the needle tip)
• Inject the MRI contrast

Question 3

How do you know you’re in the joint capsule during an arthrogram injection?

Answer 3

Inject a small amount of contrast: If the contrast flows away from the needle tip then you are in the capsule, if the contrast just pools at the needle tip then you are not in the capsule and need to adjust

Question 4

What size needle is used for hip arthrogram injections?

Answer 4

20-22 gauge spinal needle

Question 5

What is the target for a hip arthrogram injection?

Answer 5

The superior aspect of the head-neck junction (where the joint capsule is widest)

Question 6

What is injected during a hip arthrogram injection?

Answer 6

14 cc total:

• 4 cc lidocaine
• 10 cc Visipaque
• 0.1 cc Gadolinium

Question 7

What are the steps for a shoulder arthrogram injection?

Answer 7

• Supinate the hand and externally rotate the shoulder
• Clean and numb skin
• Advance needle into the joint straight down on the target (the junction between the middle and inferior third of the humeral head)
• Once you strike bone, pull back 1 mm and turn the bevel towards the humeral head
• Inject a small amount of contrast to confirm position
• Inject the remaining contrast

Question 8

What size needle is used during a shoulder arthrogram injection?

Answer 8

20-22 gauge spinal needle (same as for hip injections)

Question 9

What is the target for a fluoroscopic shoulder injection?

Answer 9

The junction between the middle and inferior thirds of the humeral head (2 mm inside the cortex)

Note: Once you hit bone inside the target area, pull back 1 mm and turn the bevel towards the humeral head before injecting.

Question 10

What is injected during a shoulder arthrogram contract injection?

Answer 10

12 cc total:

• 4 cc lidocaine
• 8 cc Visipaque
• 0.1 cc gadolinium

Question 11

What are the 3 main reasons you might be asked to put a needle inside a joint capsule?

Answer 11

• To inject contrast for an arthrogram (usually to evaluate a labrum)
• Pain management (steroid/lidocaine injection)
• Joint aspiration (if concerned for septic joint)

Question 12

Next step: Pt needs an arthrogram, but is allergic to gadolinium

Answer 12

CT arthrogram (using just Visipaque and lidocaine without the gadolinium)

Question 13

Next step: Pt needs a joint steroid injection, but is allergic to iodinated contrast

Answer 13

Inject air into the joint (to confirm position instead of using Visipaque), then inject the steroid

Question 14

Next step: Pt needs an arthrogram, but is allergic to iodinated contrast

Answer 14

Premeditate the pt and do a routine arthrogram

Note: Arthrogram injections contain iodinated contrast in addition to gadolinium.