Cortisone and platelet-rich plasma (PRP) can both be used for knee arthritis, but they are not interchangeable. Cortisone is an anti-inflammatory medication often used for short-term symptom relief. PRP is prepared from your own blood and is intended to influence the joint environment over a longer time. Neither injection regrows normal cartilage, and neither should be chosen from an X-ray alone.
The better option depends on the diagnosis, severity of arthritis, current symptoms, prior treatment, health history, activity goals, cost, and how the injection fits into a broader rehabilitation plan.
What Does a Cortisone Injection Do?
Cortisone is a corticosteroid medication placed into the joint to reduce inflammation and pain. It may be useful when a painful flare is limiting sleep, walking, rehabilitation, work, or an important near-term activity.
Relief varies. Some people improve substantially, some improve briefly, and others do not improve. Cortisone does not rebuild cartilage, repair a meniscus, or correct weakness and movement limitations. The American Academy of Orthopaedic Surgeons states that intra-articular corticosteroids can provide short-term relief for symptomatic knee osteoarthritis. Review the AAOS knee osteoarthritis guideline.
For a fuller explanation, visit our Cortisone Injections page.
What Does PRP Do?
PRP is made by concentrating platelets from a sample of your blood and injecting the prepared product into the knee. Platelets release signaling proteins involved in the body’s response to injury. PRP is used with the goal of reducing symptoms and improving function, not as a guaranteed way to restore cartilage.
The treatment is not one standardized product. Blood volume, platelet concentration, white-blood-cell content, preparation system, dose, and injection schedule can differ. These differences—and the patient’s arthritis pattern—help explain why published results and individual responses vary.
Learn how Dr. Gelber approaches PRP injections.
Which Injection Works Faster?
Cortisone is generally selected when the priority is reducing an inflammatory flare and creating a near-term window for movement or rehabilitation. PRP often has a slower onset, so it is not usually the better choice when immediate relief is the only objective.
That does not mean faster is always better. A short-term decrease in pain can be valuable, but it should be used to advance strength, mobility, sleep, conditioning, and activity tolerance. Pain relief by itself does not prove that the joint has healed.
Our related article explains what less pain after a cortisone injection does—and does not—mean.
Which May Last Longer?
Studies comparing the two treatments frequently find that cortisone performs well earlier, while PRP may provide more durable improvement for selected patients with knee osteoarthritis. A 2024 systematic review and meta-analysis of randomized trials reported better pain and function outcomes with PRP than corticosteroid at several medium- and longer-term follow-up points. Read the PubMed abstract.
Those averages cannot predict an individual result. PRP protocols vary, studies include different arthritis severities, and not every patient improves. The AAOS guideline describes the evidence supporting PRP as limited, even while noting that it may reduce pain and improve function. This is why the decision should remain individualized rather than presented as a guaranteed upgrade.
What Are the Main Tradeoffs?
- Cortisone: Often faster symptom relief; generally lower direct cost; may temporarily raise blood sugar; repeated injections require consideration of cumulative tissue effects.
- PRP: Uses a patient’s own blood; typically slower onset; preparation matters; commonly not covered by insurance; recovery may include a temporary post-injection flare.
- Both: Carry injection-related risks such as pain, bleeding, and infection; neither replaces diagnosis, rehabilitation, or appropriate surgical discussion.
Does Arthritis Severity Matter?
Yes. People with mild or moderate osteoarthritis may have different goals and treatment options than those with advanced joint-space loss, major deformity, persistent swelling, or severe limits in daily activity. Symptoms and imaging also do not always match: a dramatic X-ray can coexist with good function, while modest imaging changes can still be painful.
An evaluation should connect the X-rays with the examination and the activities that matter to you. Read more about knee osteoarthritis and the broader causes of knee pain.
Can Either Injection Help Avoid Knee Replacement?
An injection may help someone function better and postpone surgery when symptoms, anatomy, and goals support continued nonsurgical care. It cannot make every knee avoid replacement indefinitely. Surgery may be the better answer when pain and disability remain unacceptable despite appropriate nonsurgical treatment.
The useful question is not simply, “Which injection keeps me from surgery?” It is, “Which plan gives me the best balance of symptom control, capacity, risk, cost, and progress toward the activities I want to keep doing?”
Why Rehabilitation Still Matters
Exercise and neuromuscular training are central parts of knee osteoarthritis care. An injection can create an opportunity, but the longer-term plan often still includes strength, mobility, load management, conditioning, and gradual return to activity.
Progress should be measured by more than a pain score: walking tolerance, stairs, sit-to-stand strength, balance, sport-specific demands, and recovery after activity can all matter. If an injection reduces pain but activity capacity does not improve, the plan deserves reassessment.
How Dr. Gelber Chooses Between Cortisone and PRP
Dr. Gelber reviews the pain pattern, examination, imaging, prior response to treatment, medical risks, timeline, and activity goals. Cortisone may fit a short-term inflammatory flare. PRP may be considered when the goal is a longer treatment horizon and the diagnosis, evidence, and patient preferences support it. Sometimes neither injection is the best next step.
The recommendation is based on fit—not on selling a procedure. If knee arthritis is limiting golf, tennis, pickleball, hiking, exercise, travel, or everyday movement, schedule an orthopedic evaluation with Dr. Gelber.
This article is for general education and does not replace an individual medical evaluation.
