Key Takeaways
- Corticosteroid injections provide rapid but short-term relief (4-6 weeks) for acute inflammatory flares, backed by High evidence quality, but repeated use may risk cartilage damage over time.
- PRP and genicular nerve RFA offer longer-lasting relief (6-12 months) for mild-to-moderate osteoarthritis, with success rates of 60-80% in well-selected patients, making them superior options for sustained pain management.
- Hyaluronic acid has weak evidence, and many medical guidelines now recommend against its routine use due to minimal clinically significant benefit compared to placebo and increased risk of adverse events.
- Costs vary dramatically from $150-$300 for corticosteroids to $1,000-$3,000 for PRP, with insurance coverage differing significantly. Medicare typically covers 80% after the deductible, but PRP is often out-of-pocket.
- The best injection depends on your specific situation, severity of osteoarthritis, age, prior treatment response, and whether you’re a surgical candidate; all these factors influence which option will provide optimal results for your unique needs.
Knee pain affects millions of people worldwide, limiting mobility and diminishing quality of life. When physical therapy, medications, and lifestyle modifications aren’t enough, knee injections offer a targeted approach to pain relief without the risks and recovery time of surgery. But with multiple injection types available, from corticosteroids and hyaluronic acid to platelet-rich plasma and genicular nerve blocks, how do you know which option is right for you?
Understanding the best injection for knee pain requires comparing effectiveness, duration, and evidence quality across all available treatments. This comprehensive guide breaks down the science behind each injection type, compares their effectiveness and duration, and helps you understand what to expect from costs to potential complications.
What Are The Main Types Of Injections For Knee Pain?
Four primary injection types treat knee pain, each working differently to provide relief. Corticosteroid injections are potent anti-inflammatory agents that suppress the immune response, directly reducing pain and swelling in the knee joint. Hyaluronic acid, or viscosupplementation, introduces a gel-like substance that mimics synovial fluid’s natural lubricating and shock-absorbing properties.
Platelet-rich plasma (PRP) takes a different approach by using your body’s own healing mechanisms. This autologous treatment concentrates platelets, growth factors, and bioactive proteins from your blood to promote tissue repair. Genicular nerve blocks target pain transmission itself by delivering anesthetic medication around the specific nerves that carry pain signals from the knee, often combined with corticosteroids for extended relief.
While stem cell injection for knee pain represents an emerging treatment option, current research focuses primarily on these four established interventions.
How Do Knee Injections Relieve Pain?
Each injection type attacks knee pain through distinct mechanisms. Corticosteroids work by suppressing the inflammatory cascade at the cellular level, blocking the immune response that causes joint swelling and pain. This direct anti-inflammatory action makes them particularly effective for acute flares.
Hyaluronic acid addresses the mechanical breakdown of osteoarthritis. When cartilage deteriorates, the joint loses its natural lubrication. Viscosupplementation restores this fluid cushion, improving joint mechanics and shock absorption. PRP injection for knee pain leverages concentrated growth factors to stimulate the body’s healing response, reducing inflammation while promoting actual cartilage and tissue repair at the cellular level.
Genicular nerve blocks interrupt pain at the source of signal transmission. By blocking the superior medial, superior lateral, and inferior medial genicular nerves, these injections prevent pain messages from reaching your brain. When combined with radiofrequency ablation (RFA), the treatment creates a controlled lesion on the nerve itself, disrupting its pain-signaling function for months rather than hours.
What Are The Pros And Cons Of Each Type Of Knee Injection?
Corticosteroid Injections
Pros:
- High effectiveness for short-term relief (High evidence quality)
- Rapid pain relief for acute flares
- Relief lasts 4-6 weeks, up to 3 months in some cases
- Best for calming painful, swollen knee flare-ups
- Quick outpatient procedure with minimal downtime
Cons:
- Short-lived relief, not a long-term solution
- Benefits rarely extend beyond 6-8 weeks
- Moderate to Low evidence quality for long-term efficacy
- Repeated use may cause cartilage damage
- Temporary post-injection flare possible
Hyaluronic Acid (Viscosupplementation)
Pros:
- May last up to 6 months
- Minimal downtime with temporary injection site pain and swelling
Cons:
- Mixed/Low evidence quality
- High-quality systematic reviews show minimal, clinically insignificant pain relief versus placebo
- Increased risk of serious adverse events (49% higher than placebo)
- Many medical societies recommend against routine use
- Weak evidence for meaningful benefit
Platelet-Rich Plasma (PRP)
Pros:
- Moderate evidence quality
- Provides moderate pain relief and improved function for 6-12 months
- Some studies show benefits extending to 2 years
- 60-70% success rate for pain relief lasting 6-12 months
- Generally safe using patient’s own blood
- Low risk with primarily mild, self-limiting side effects
- Appropriate for mild to moderate osteoarthritis (Kellgren-Lawrence grade 0-III)
Cons:
- Variable results between patients
- Not always effective for everyone
- Limited evidence for long-term cartilage repair
- Inconsistency from varying PRP preparation methods
- More large-scale, high-quality trials needed
Genicular Nerve Blocks (with RFA)
Pros:
- Moderate to High evidence quality for durable pain relief
- Diagnostic block confirms candidacy (>50% pain relief during test)
- With RFA: pain relief often lasts 6-12 months or longer
- 60-80% success rate for RFA in reducing chronic knee pain
- Minimal downtime for diagnostic block
- Good option for patients who fail other treatments or aren’t surgical candidates
Cons:
- Diagnostic block lasts only a few hours (temporary)
- Few days of soreness after RFA
- Requires diagnostic test before therapeutic treatment
- Not a first-line treatment (used after conservative options fail)
How Do You Choose The Right Knee Injection For Your Pain?
Selecting the right knee injection depends on your pain pattern, osteoarthritis severity, and treatment history. For acute flares with visible swelling and inflammation, corticosteroid injections deliver rapid symptom control when conservative measures like physical therapy and over-the-counter medications have failed. These work best as short-term interventions to calm an inflammatory episode, not as ongoing treatment.
Patients with mild to moderate osteoarthritis (Kellgren-Lawrence grade 0-III) who experience persistent pain despite conservative care are ideal candidates for PRP therapy. This typically applies to individuals 80 years or younger who need longer-lasting relief than corticosteroids provide. When comparing cortisone shot vs PRP knee options, treatment often progresses in stages, starting with a corticosteroid injection for immediate relief, then transitioning to PRP for sustained improvement, as demonstrated in Sarah’s case where initial steroid relief lasted three months before PRP provided year-long benefits.
Genicular nerve blocks with RFA become appropriate when chronic knee pain persists despite exhausting other options. These suit patients who aren’t surgical candidates or those whose osteoarthritis pain stems primarily from nerve signals rather than mechanical joint problems. A diagnostic block serves as the critical screening tool, if you experience more than 50% pain relief during the test, you’re likely to benefit from the longer-lasting RFA treatment.
This approach works best after confirming that physical therapy, medications, and other injections haven’t provided adequate relief.
What Are The Risks And Side Effects Of Knee Pain Injections?
Corticosteroid Injections
Common Side Effects:
- Post-injection flare (temporary)
- Local skin changes and discoloration
Serious Risks:
- Infection (1 in 10,000 to 1 in 20,000 injections)
- Cartilage damage with repeated use
- Tendon rupture (extremely rare)
Hyaluronic Acid (Viscosupplementation)
Common Side Effects:
- Injection site pain
- Swelling
- Joint fluid buildup (effusion)
Serious Risks:
- 49% higher risk of serious adverse events versus placebo
- Pseudo-septic reactions (rare)
- Joint infections (rare but possible)
Platelet-Rich Plasma (PRP)
Common Side Effects:
- Temporary injection site pain
- Swelling
- Stiffness
Serious Risks:
- Infection (rare)
- Generally considered very safe with a low risk profile
- Most adverse events are mild and self-limiting
Genicular Nerve Blocks
Common Side Effects:
- Temporary pain at the injection site
- Bruising
- Few days of soreness after RFA
Serious Risks:
- Nerve irritation
- Infection (very rare)
- Serious complications uncommon when performed by experienced practitioners under imaging guidance
How Much Do Knee Pain Injections Cost?
Cost varies significantly based on location, provider, insurance coverage, and whether the procedure is performed in a hospital outpatient department versus a physician’s office. Below are typical price ranges for each injection type.
| Injection Type | Average Cost (Without Insurance) | Typical Insurance Coverage | Cost Factors |
| Corticosteroid | $150-$300 per injection | Medicare: 80% after deductible
Private: Often covered when medically necessary |
• Provider location
• Facility fees • Imaging guidance use |
| Hyaluronic Acid | $500-$1,500 per injection
(Series of 1-5 injections) |
Medicare Part B: May cover 80%
Private: Coverage varies widely, often covered |
• Brand/formulation
• Number of injections required • Hospital vs. office setting |
| PRP | $1,000-$3,000 per treatment
(Most commonly $1,000-$1,500) |
Often NOT covered by insurance
Typically out-of-pocket expense |
• Preparation complexity
• Provider expertise • Geographic location • Number of injections |
| Genicular Nerve Block (Diagnostic) | Typically bundled with RFA cost | Medicare: 80% after deductible
Private: Usually covered when medically necessary |
• Part of two-step process
• Imaging guidance • Provider setting |
| Radiofrequency Ablation (RFA) | $2,000-$7,000
(Genicular nerve: $1,000-$10,000) |
Medicare: 80% after deductible
Private: Often covered with prior authorization |
• Procedure complexity
• Cooled vs. conventional RFA • Hospital vs. ASC setting • Geographic location |
Key Cost Considerations:
Medicare patients typically pay 20% coinsurance after meeting the annual deductible ($257 in 2025). For a $1,000 approved procedure, the out-of-pocket cost would be $200. Private insurance coverage varies significantly; some plans cover injections fully, while others offer partial coverage or exclude certain types (particularly PRP).
Hospital outpatient departments charge higher facility fees than physician offices or ambulatory surgery centers, significantly affecting total cost. Always verify coverage and get pre-authorization before scheduling any procedure to avoid unexpected expenses.
How Effective Are Knee Injections Compared To Other Treatments For Knee Pain?
Knee injections serve as an intermediate treatment option between conservative care and surgery. Physical therapy remains the first-line treatment, with studies showing superior long-term outcomes compared to corticosteroid injections alone. Patients in physical therapy groups demonstrated better pain scores and function at one year.
However, injections become valuable when conservative treatments fail to provide adequate relief. The evidence hierarchy places corticosteroid injections highest for short-term relief (High evidence quality), followed by genicular nerve RFA (Moderate to High), PRP (Moderate), and hyaluronic acid (Mixed/Low, with many guidelines recommending against routine use).
The typical treatment progression involves exhausting conservative options first. Patients often start with physical therapy and oral medications, advance to injections for symptom control, and may eventually consider surgery if all else fails. Injections frequently serve as “bridge” therapies, providing enough relief to participate more effectively in physical therapy or delaying surgical intervention.
Success rates vary significantly: RFA for facet-mediated pain is considered standard of care with 60-80% success rates when preceded by positive diagnostic blocks, while PRP demonstrates 60-70% success for meaningful relief in mild-to-moderate osteoarthritis. Most importantly, injections can reduce medication dependence and improve quality of life enough to engage in rehabilitative activities.
How Long Do Knee Pain Injections Last?
Corticosteroid Injections
- Expected duration: 4-6 weeks typically
- Maximum duration: Up to 3 months in some cases
- Repetition: Can be repeated, but frequent use discouraged due to potential cartilage damage
- Clinical note: Benefits rarely extend beyond 6-8 weeks
Hyaluronic Acid (Viscosupplementation)
- Claimed duration: Up to 6 months
- Repetition: Series of 1-5 injections administered weekly
- Evidence note: Weak evidence for meaningful duration; pain reduction often clinically insignificant compared to placebo
Platelet-Rich Plasma (PRP)
- Expected duration: 6-12 months typically
- Extended duration: Some studies report benefits up to 2 years
- Repetition: Single injection or series of 2-3 injections over several weeks
- Clinical note: Duration varies based on PRP preparation, protocol, and individual factors
Genicular Nerve Blocks
- Diagnostic block: Few hours only (temporary test to confirm candidacy)
- Therapeutic block with corticosteroid: Days to a few weeks
- With RFA: 6-12 months or longer
- Repetition: RFA can be safely repeated if pain returns as nerves regenerate
- Requirement: Diagnostic block must show >50% pain relief before proceeding to RFA
Which Knee Pain Injection Is Right For You?
The best knee injection depends on your pain pattern, treatment history, and goals. Success means achieving at least 50% pain reduction and improving daily function, walking further, sleeping better, and returning to activities you enjoy. For acute inflammatory flares, corticosteroid injections offer rapid relief lasting 4-6 weeks (High evidence quality). For longer-lasting relief in mild-to-moderate osteoarthritis, PRP (6-12 months, Moderate evidence) and genicular nerve RFA (6-12+ months, Moderate to High evidence) show stronger results. Hyaluronic acid carries Mixed/Low evidence with minimal clinically significant benefit, leading many medical societies to recommend against routine use.
Your candidacy depends on multiple factors: severity of osteoarthritis (Kellgren-Lawrence grading), age (PRP appropriate for ≤80 years), response to previous treatments, surgical candidacy, and specific pain characteristics. All procedures carry risks and benefits that must be weighed individually. The decision requires shared decision-making with your physician, discussing expected pain reduction percentages, functional improvement goals, duration of relief needed, tolerance for repeated procedures, and cost considerations. This isn’t about finding the “best” injection universally; it’s about finding the right intervention for your unique situation, medical history, and treatment objectives.
Ready to explore Newport Beach knee pain treatment options? Contact our specialists at OrthoRepair for a personalized consultation and evidence-based treatment plan tailored to your needs.
