When getting a joint injection, accuracy matters. That’s where fluoroscopy comes in - it’s the technology that helps doctors see exactly where they’re placing the needle.
What Is Fluoroscopy?
Fluoroscopy is a type of medical imaging that shows real-time, moving X-ray images on a screen. Think of it like a live video feed of your bones and joints.
During a fluoroscopy-guided injection, the doctor watches the screen while guiding the needle into your joint. This lets them see exactly where the needle tip is at every moment - no guessing involved.
How Does It Work?
The process is straightforward:
- Positioning - You lie on a special table with the X-ray machine nearby
- Live imaging - The fluoroscopy unit shows your joint on a screen in real time
- Needle guidance - Your doctor watches the screen while advancing the needle
- Contrast confirmation - A small amount of dye is injected to verify the needle is in the right spot
- Treatment delivery - Once placement is confirmed, the medication is injected
The contrast dye step is key. It spreads through the joint space, appearing bright on the screen. This confirms the medication will go exactly where it’s needed.
Why Does Accuracy Matter?
Studies show that 20-30% of “blind” injections (done without imaging guidance) miss the joint space entirely.
When an injection misses, you might:
- Get less pain relief than expected
- Need to repeat the procedure
- Experience discomfort without the full benefit
This matters more for some joints than others. Your knee is relatively large and close to the surface - it’s easier to access by feel. But your hip sits deep beneath muscle and tissue. Without imaging, even experienced doctors can miss.
For deeper joints like the hip and shoulder, imaging guidance isn’t just helpful - it’s often essential.
Is Fluoroscopy Safe?
Yes. The radiation exposure from a fluoroscopy-guided injection is minimal - roughly equivalent to a few hours of natural background radiation or a chest X-ray.
For context: you’re exposed to background radiation every day from the sun, soil, and building materials. A single fluoroscopy procedure adds very little to your annual exposure.
That said, fluoroscopy is used thoughtfully. Doctors limit the imaging time and use the lowest effective dose. The brief exposure during an injection procedure is considered very safe.
Fluoroscopy vs. Ultrasound vs. Blind Injection
Doctors use three main approaches for joint injections. Here’s how they compare:
| Factor | Fluoroscopy | Ultrasound | Blind (No Imaging) |
|---|---|---|---|
| Accuracy | Near 100% | 90-95% | 70-80% |
| Sees bone | Yes | No | No |
| Sees soft tissue | No | Yes | No |
| Contrast confirmation | Yes | No | No |
| Radiation | Minimal | None | None |
| Best for | Deep joints (hip, shoulder) | Superficial joints | Simple, accessible joints |
| Cost | Higher | Moderate | Lower |
Bottom line: Fluoroscopy offers the highest accuracy with contrast confirmation. Ultrasound is a good radiation-free option for many joints. Blind injections can work for simple knee injections but have higher miss rates.
What to Expect During a Fluoroscopy-Guided Injection
The procedure typically takes 15-30 minutes and happens in an outpatient setting. Here’s what to expect:
Before:
- You’ll change into a gown (metal objects can interfere with imaging)
- The area will be cleaned and possibly numbed with local anesthetic
During:
- You’ll lie still while the doctor positions the fluoroscopy unit
- You may feel pressure as the needle is inserted
- The injection itself takes only a minute or two
After:
- You can usually leave within 15-30 minutes
- Most people drive themselves home
- Mild soreness at the injection site is normal for 1-2 days
- Your doctor may recommend avoiding strenuous activity for 24-48 hours
When Fluoroscopy Matters Most
While all joints can benefit from imaging guidance, fluoroscopy is especially valuable for:
- Hip injections - The hip joint is deep and surrounded by large muscles
- Shoulder injections - Multiple structures in a small space require precision
- Spine injections - Accuracy is critical near the spinal cord
- Failed previous injections - When blind attempts haven’t worked
If you’ve had an injection that didn’t seem to help, poor placement may have been the issue. A repeat injection with fluoroscopy guidance often produces better results.
The Bottom Line
Fluoroscopy is a proven technology that helps ensure your joint injection goes exactly where it’s supposed to. The minimal radiation exposure is well worth the near-perfect accuracy, especially for deeper joints where blind injections frequently miss.
When considering any joint injection, it’s reasonable to ask your provider what guidance method they use - and whether fluoroscopy might be appropriate for your specific situation.
Learn more: Why Injection Accuracy Matters: The Case for Fluoroscopic Guidance | Complete Guide to Imaging-Guided Injections