Joint Injection Complications: Rare But Important to Know

Key Takeaways

Serious complications from joint injections are very rare (infection risk is less than 1 in 1,000)
Recognizing warning signs early ensures prompt treatment if complications do occur
Imaging guidance and proper sterile technique significantly reduce risks
Most side effects are mild and temporary, resolving within a few days
Asking your provider about their safety protocols helps you make informed decisions

Joint injections have helped millions of people find relief from arthritis pain. The good news is that serious complications are rare—occurring in less than 1% of procedures. But like any medical treatment, it’s important to understand what could happen and what warning signs to watch for.

This guide gives you the full picture about injection safety, so you can make informed decisions and know when to seek help if something doesn’t feel right.

Understanding the Overall Safety Picture

Before we dive into specific complications, let’s put the risks in perspective.

Joint injections have been used for over 50 years with an excellent safety record. Research shows that complications happen in less than 1% of procedures. For comparison, you’re more likely to have complications from common medications like ibuprofen than from a properly performed joint injection.

That said, no medical procedure is completely risk-free. Being informed about potential complications doesn’t mean they’re likely to happen to you—it means you’ll know what’s normal and what requires attention.

Infection: The Most Serious (But Very Rare) Risk

Infection inside the joint—called septic arthritis—is the complication doctors worry about most. Fortunately, it’s also very rare.

How Rare Is Infection?

Studies show infection occurs in approximately 1 in 3,000 to 1 in 15,000 joint injections. The risk is lowest when:

Sterile technique is strictly followed
The injection site is properly cleaned
The provider uses single-use, sterile equipment
The patient doesn’t have active skin infections near the injection site

Warning Signs of Infection

Call your doctor immediately if you experience:

Increasing pain that gets worse instead of better after 24-48 hours
Fever (temperature above 100.4°F)
Warmth and redness around the joint that’s spreading
Swelling that increases rather than improves
Inability to move the joint or put weight on it
Chills or feeling generally unwell

Infections usually develop within 2-7 days after the injection. Early treatment with antibiotics is highly effective, which is why recognizing symptoms matters.

How Providers Prevent Infection

Reputable clinics follow strict protocols:

Cleaning the skin with antiseptic solution
Using sterile gloves and equipment
Avoiding injections if you have active skin infections
Not injecting through areas with psoriasis or eczema
Keeping the procedure area strictly sterile

Red flag: If your provider isn’t wearing gloves, doesn’t clean your skin thoroughly, or the environment seems unclean, that’s a serious concern.

Allergic Reactions: Uncommon But Manageable

True allergic reactions to joint injections are uncommon, but they can happen.

Types of Reactions

Mild reactions might include:

Temporary rash or hives
Itching near the injection site
Mild swelling beyond the joint

Serious reactions (very rare) include:

Difficulty breathing
Swelling of face or throat
Rapid heartbeat
Dizziness or feeling faint

What Causes Allergic Reactions?

Most reactions are to the medication itself:

Corticosteroids (like cortisone): Very rare allergies
Hyaluronic acid: Can occur, especially with avian (bird) protein sensitivity in some older HA products
Local anesthetic: Some people are allergic to lidocaine or similar numbing agents
Preservatives: Some products contain preservatives that may cause reactions

Important: Tell your provider about any known allergies before your injection, including allergies to eggs, feathers, or local anesthetics.

Modern hyaluronic acid products like Synvisc-One and Euflexxa are highly purified and have lower allergy rates than older formulations.

Nerve or Blood Vessel Injury: Very Rare

The knee and other joints have nerves and blood vessels nearby. In rare cases, an injection needle might contact these structures.

What This Looks Like

Nerve contact: Sharp, shooting pain during injection (tell your provider immediately if this happens)
Blood vessel injury: Unusual bleeding or bruising

How Imaging Guidance Helps

This is where modern technique makes a big difference. Fluoroscopy (real-time X-ray guidance) allows doctors to see exactly where the needle is going.

With imaging guidance:

The provider can avoid important structures
Accuracy improves to over 95%
Complications from misplaced injections decrease significantly

Question to ask: “Do you use imaging guidance for joint injections?”

Clinics that use fluoroscopy demonstrate a higher standard of care and patient safety.

Pseudosepsis: Looks Like Infection But Isn’t

Sometimes called “steroid flare” or “crystal-induced synovitis,” pseudosepsis is a temporary inflammatory reaction that mimics infection.

What Happens

After a corticosteroid injection, some people experience:

Increased pain and swelling within 24-48 hours
Warmth around the joint
Redness
These symptoms typically resolve within 2-3 days

This happens when steroid crystals temporarily irritate the joint lining. It’s uncomfortable but not dangerous and doesn’t require antibiotics.

How to Tell the Difference

Pseudosepsis	Actual Infection
Peaks within 24-48 hours	Worsens after 48 hours
No fever (or low-grade)	Fever above 100.4°F
Starts improving by day 3	Continues getting worse
No chills or feeling unwell	Systemic symptoms (chills, fatigue)

When in doubt, call your provider. It’s better to check and be reassured than to delay treatment for a real infection.

Temporary Side Effects (Common and Not Concerning)

Most people experience minor, temporary side effects that aren’t complications:

Normal Post-Injection Symptoms

Soreness at injection site: Like getting a flu shot, lasts 1-2 days
Mild swelling: Usually improves within 48 hours
Temporary stiffness: May last a day or two
Slight warmth: Without increasing redness or pain

What helps:

Ice the joint for 15-20 minutes several times daily
Rest the joint for 24-48 hours
Take acetaminophen (Tylenol) if needed for discomfort
Avoid strenuous activity for a few days

Questions to Ask About Safety

Before getting a joint injection, these questions help you understand your provider’s safety protocols:

“What’s your infection rate?”
- Good answer: Less than 1 in 1,000 or “We haven’t had an infection in [recent timeframe]”
- Red flag: They can’t answer or seem defensive
“Do you use imaging guidance?”
- Best answer: Yes, fluoroscopy or ultrasound
- Acceptable: No for simple knee injections, but yes for hip or shoulder
- Red flag: Never uses imaging for any joint
“What sterile precautions do you take?”
- Look for: Mention of skin prep, sterile gloves, single-use equipment
“What should I watch for after the injection?”
- Good answer: Specific warning signs and when to call
“Have you had any complications with this type of injection?”
- Good answer: Honest discussion about extremely low risk
- Red flag: Guarantees nothing can go wrong

When to Seek Emergency Care

Go to the emergency room or call 911 if you experience:

Difficulty breathing or swallowing (possible severe allergic reaction)
High fever (above 101°F) with severe joint pain
Complete inability to move the joint or bear weight
Rapid swelling of the joint within hours of injection
Chest pain, rapid heartbeat, or feeling faint

These symptoms are very rare but require immediate attention.

How Proper Technique Minimizes All Risks

The quality of care matters enormously in preventing complications. Here’s what distinguishes excellent providers:

Comprehensive Patient Screening

Before your injection:

Review of your complete medical history
Check for active infections
Review medications (some may need temporary adjustment)
Discussion of allergies
Assessment of whether you’re a good candidate

Sterile Procedure Environment

Clean, clinical setting
Proper skin preparation with antiseptic
Sterile equipment and technique
Appropriate protective equipment for staff

Imaging Guidance

Fluoroscopy or ultrasound for accuracy
Ensures medication goes exactly where intended
Minimizes risk of nerve or vessel injury

Clear Post-Procedure Instructions

Written instructions about what to expect
Specific warning signs to watch for
Direct number to call with concerns
Follow-up appointment scheduled

Medicare Compliance

Clinics that accept Medicare must meet specific quality and safety standards. This provides an additional layer of assurance that proper protocols are followed.

The Bottom Line on Joint Injection Safety

Joint injections remain one of the safest and most effective treatments for arthritis pain. Serious complications are rare, especially when:

Your provider follows proper sterile technique
Imaging guidance is used when appropriate
You’re properly screened before the procedure
You know what warning signs to watch for

Most people experience only minor, temporary soreness and go on to enjoy significant pain relief for months.

Understanding potential complications isn’t meant to scare you—it’s meant to empower you to make informed decisions and recognize the rare situations that need attention.

If you’re considering joint injections, choose a provider who takes safety seriously, uses modern techniques, and takes time to answer your questions. That combination gives you the best chance of a safe, successful outcome.

Frequently Asked Questions

How common are serious complications from joint injections?

Serious complications occur in less than 1% of joint injections. Infection, the most concerning complication, happens in approximately 1 in 3,000 to 1 in 15,000 procedures when proper sterile technique is used.

What’s the difference between normal soreness and a complication?

Normal soreness is mild, stays at the injection site, and improves within 2-3 days. A complication involves worsening symptoms, fever, spreading redness, or increasing inability to use the joint. When in doubt, contact your provider.

Does imaging guidance really make injections safer?

Yes. Studies show imaging guidance (fluoroscopy or ultrasound) improves accuracy to over 95% and significantly reduces the risk of nerve injury, blood vessel damage, and medication placement errors.

Can I be allergic to joint injection medication?

Allergies to joint injection medications are uncommon but possible. Modern hyaluronic acid products are highly purified with lower allergy rates than older versions. Always inform your provider of any known allergies, especially to eggs, feathers, or local anesthetics.

What should I do if I’m worried about infection after my injection?

Contact your provider immediately if you experience increasing pain, fever above 100.4°F, spreading redness, worsening swelling, or inability to move the joint. Early treatment is highly effective if infection does occur.

Are joint injections safer than taking pain medication long-term?

For many people, yes. Long-term use of NSAIDs (like ibuprofen) carries risks of stomach ulcers, kidney problems, and heart issues. When performed properly, joint injections have fewer systemic risks and can reduce the need for daily medication.

This article is for informational purposes only and does not replace medical advice. Consult with a qualified healthcare provider about whether joint injections are appropriate for your specific condition. If you experience concerning symptoms after an injection, contact your provider or seek emergency care.

Last reviewed: March 2025