If you have knee arthritis, you've probably heard of at least one injection that's supposed to help — cortisone from your primary care doctor, "gel shots" from an orthopedist, PRP from a sports medicine clinic, or a nerve block from a pain specialist. They are all real options. They are also genuinely different: different mechanisms, different durations, different costs, and different ideal patients.
Quick answer: Cortisone is the fastest and cheapest but shortest-lasting. Gel (hyaluronic acid) injections lubricate the joint for up to 6 months and are insurance-covered. PRP uses your own platelets to reduce inflammation longer-term but is usually cash-pay. A genicular nerve block — and the radiofrequency ablation it can lead to — quiets the nerves that carry knee pain, and is the strongest option for bone-on-bone arthritis or pain after knee replacement.
The Four Options Side by Side
| Cortisone | Gel (Hyaluronic Acid) | PRP | Genicular Nerve Block → RFA | |
|---|---|---|---|---|
| What it is | Powerful steroid anti-inflammatory injected into the joint | Lubricating gel that mimics natural joint fluid | Concentrated platelets from your own blood | Numbing/quieting the small nerves that carry knee pain signals |
| Best for | Acute flares; short-term relief; confirming the joint is the pain source | Mild-to-moderate arthritis; patients wanting insurance-covered, repeatable relief | Mild-to-moderate arthritis in patients seeking longer biologic benefit | Advanced (bone-on-bone) arthritis, surgery-ineligible patients, pain after knee replacement |
| Onset | Days | 2–4 weeks | 4–8 weeks | Block: immediate (diagnostic). RFA: 1–3 weeks |
| Typical duration | 6–12 weeks | Up to 6 months | 6–12 months in responders | RFA: 6–12+ months, repeatable |
| Insurance | Covered | Covered by most plans & Medicare for knee OA | Usually NOT covered (cash-pay) | Covered by most plans & Medicare when indicated |
| Caveats | Repeated use may accelerate cartilage wear; usually limited to 3–4/year | Works best before arthritis is severe | Evidence is promising for knee OA but response varies; studies show improved pain and function vs. comparators | Requires a positive diagnostic block before RFA |
Cortisone: Fast, Covered, Short-Lived
The corticosteroid injection is the default first injection for a painful, swollen knee — and for an acute flare it's a good one. Relief arrives within days. The limitation is durability: benefit typically fades within 6–12 weeks, and repeated steroid exposure may accelerate cartilage loss in an already-arthritic joint, which is why most physicians cap the frequency. Cortisone is best used strategically, not as a long-term plan. Dr. Qureshi offers image-guided joint injections so the medication lands exactly where it should.
Gel Injections: The Insurance-Covered Middle Ground
Hyaluronic acid viscosupplementation — the "gel shot" or "rooster comb" injection — replaces the lubricating fluid that arthritic knees lose. Unlike PRP, it is FDA-approved for knee osteoarthritis and covered by most insurance plans and Medicare. Relief builds over 2–4 weeks and can last up to 6 months, making it a practical, repeatable option for osteoarthritis that's outgrown cortisone but isn't ready for surgery. Full details on our knee gel injection page.
PRP: Your Own Biology, Longer Horizon
Platelet-rich plasma concentrates the growth factors in your own blood and injects them into the joint to dampen the inflammatory cycle of arthritis. Clinical studies in knee osteoarthritis show meaningful improvements in pain and function, often outlasting both cortisone and gel in responders. The trade-offs: insurance almost never covers it, results take 4–8 weeks to build, and response varies between patients. See our PRP therapy page for candidacy and pricing.
Genicular Nerve Block → RFA: For Knees Beyond Injections Into the Joint
When arthritis is bone-on-bone, when cortisone and gel have stopped working, or when pain persists after a knee replacement, injecting the joint itself often has little left to offer. The genicular nerve pathway takes a different approach entirely: instead of treating the joint, it quiets the small sensory nerves that carry the knee's pain signal. A diagnostic genicular nerve block first confirms the approach works for you; genicular radiofrequency ablation then provides 6–12+ months of relief — repeatable, insurance-covered, and available to patients who can't or don't want to have surgery.
How to Choose
The honest framework Dr. Qureshi uses with patients at his Katy office: match the tool to the stage of your arthritis and your goals. Early arthritis flaring occasionally → strategic cortisone. Moderate arthritis needing repeatable, covered relief → gel injections. Moderate arthritis in a patient wanting maximum duration and comfortable with cash-pay → PRP. Advanced or post-replacement pain → the genicular pathway. And at every stage, the injection is paired with the strengthening and activity work that actually changes the knee's trajectory — see our knee arthritis page for the full picture.
Frequently Asked Questions
Which knee injection lasts the longest?
For most patients: genicular radiofrequency ablation (after a positive nerve block) lasts longest at 6–12+ months, followed by PRP (6–12 months in responders), gel injections (up to 6 months), and cortisone (6–12 weeks). Duration also depends on arthritis severity — advanced arthritis shortens the benefit of anything injected into the joint itself.
What is the best injection for bone-on-bone knee arthritis?
When arthritis is bone-on-bone, intra-articular options like cortisone and gel often underperform because there is little joint surface left to protect. The genicular nerve block followed by radiofrequency ablation is typically the strongest option — it treats the pain signal rather than the joint surface, and is insurance-covered.
Are knee injections covered by insurance in Katy, TX?
Cortisone, gel (hyaluronic acid) injections, and genicular nerve blocks/RFA are covered by most major plans and Medicare when medically indicated. PRP is generally cash-pay. Dr. Qureshi's office at 23501 Cinco Ranch Blvd, Suite G205 in Katy verifies coverage before any procedure — call (281) 982-2144.
Can knee injections be combined?
Yes, in sequence rather than simultaneously. A common path is cortisone for an acute flare, then gel or PRP for maintenance — or a transition to the genicular pathway when joint injections stop delivering. Spacing matters (steroids can blunt PRP's biology if given together), so the sequence is planned deliberately.
Do knee gel injections or PRP work better?
They solve different problems. Gel is insurance-covered, FDA-approved for knee osteoarthritis, and reliably buys up to 6 months of lubrication-based relief. PRP costs more out of pocket but in responders produces longer, biology-based improvement in pain and function. Many patients start with gel for practical reasons and consider PRP if they want a longer horizon.
Questions About Your Treatment Options?
Same-week appointments available for new patients in Katy and surrounding areas.
Book a Consultation ›