Most patients arrive at the decision point the same way. The knee has been hurting for months. Physical therapy has helped some but not enough. The orthopedist mentions injections as the next step. And then comes the choice: a cortisone shot that is usually covered by insurance and available next week, or PRP that requires a separate consultation and significant out-of-pocket cost.
Phrased that way, the decision sounds simple. But the full picture is more complicated, and it matters. Cortisone and PRP do different things biologically. They have different effects on the underlying tissue. They have different evidence profiles for different conditions. And the decision between them affects not just the next three months, but often the long-term trajectory of the joint or tendon being treated.
This article walks through what each injection actually does, where each has the strongest evidence, and how to think about the decision when you are the one facing it.
What a Cortisone Shot Actually Does
Cortisone injections deliver a synthetic corticosteroid, usually a compound like triamcinolone or methylprednisolone, directly into an inflamed joint, bursa, or tendon sheath. The goal is to suppress the local inflammatory response.
Corticosteroids work by broadly inhibiting the production of inflammatory signaling molecules. The pathway includes prostaglandins, leukotrienes, and several cytokines. By suppressing these signals, cortisone reduces swelling, redness, and pain. The effect is often dramatic. Patients who could not walk up stairs the week before may feel significant relief within days of injection, sometimes within hours.
This pain relief is real and valuable for patients whose quality of life has been compromised by inflammatory pain. Cortisone remains a legitimate tool in the orthopedic toolkit. But it is important to understand what cortisone is not doing.
Cortisone is not healing tissue. It is not repairing cartilage or rebuilding tendon. It’s turning down the volume on the body’s inflammatory alarm system. The underlying problem, whether osteoarthritis, tendinopathy, or bursitis, remains present. The pain signal has been suppressed.
The Concerns with Repeated Cortisone
For many patients, a single cortisone injection provides months of relief and acceptable outcomes. The concerns emerge with repeated use.
Research over the last decade has raised questions about the long-term effects of repeated corticosteroid injections on joint and tendon tissue. A 2017 randomized trial published in JAMA found that patients with knee osteoarthritis who received cortisone injections every three months over two years had significantly greater cartilage loss than patients who received saline placebo injections over the same period. The steroid group had better symptom control in the short term but worse cartilage structure in the long term.
Similar concerns have emerged for tendon injections. Corticosteroids appear to weaken tendon tissue when injected repeatedly, which is why most orthopedists limit patients to no more than a few cortisone injections in a given tendon over their lifetime.
The pattern matters. An occasional cortisone injection for a severe flare is one thing. A quarterly cortisone injection as the ongoing management strategy for a chronic problem is another. The second pattern carries real concerns about accelerating the underlying tissue degeneration.
What PRP Actually Does
PRP, or platelet-rich plasma, works through an entirely different mechanism. A sample of the patient’s own blood is drawn and processed in a centrifuge to concentrate the platelets. These concentrated platelets, suspended in a small volume of plasma, are then injected into the target tissue.
Platelets are best known for their role in blood clotting, but they are also reservoirs of growth factors and signaling molecules involved in tissue repair. When platelets are delivered to an injury site at high concentration, they release growth factors including platelet-derived growth factor, transforming growth factor beta, vascular endothelial growth factor, and insulin-like growth factor. These factors initiate and amplify the body’s own tissue repair processes.
PRP does not suppress inflammation the way cortisone does. In fact, PRP can transiently increase local inflammation as part of its mechanism, because early inflammation is a necessary stage in tissue repair. Patients sometimes experience a temporary worsening of symptoms in the days after a PRP injection before improvement begins.
The important point is that PRP is attempting to heal the underlying tissue, not mask the symptoms. This means PRP is slower to produce pain relief, often weeks rather than days, and the effects tend to be more durable when they do occur.
Where the Evidence Is Strongest for Each
The evidence for both treatments is not identical across every condition. Each has specific clinical situations where research support is particularly strong.
Cortisone has the strongest evidence in situations where inflammation is the dominant driver of pain and short-term relief is the primary goal. Acute bursitis responds well. Rheumatoid arthritis flares benefit. Certain forms of nerve root inflammation, when steroid is delivered epidurally by a qualified specialist, show good short-term outcomes. Cortisone is also often used preoperatively to reduce inflammation before surgical intervention.
PRP has the strongest evidence in tendon and ligament conditions where chronic degeneration rather than acute inflammation is the underlying problem. Tennis elbow, or lateral epicondylitis, has strong research support for PRP, including head-to-head studies where PRP outperformed cortisone at one-year follow-up. Patellar tendinopathy, often called jumper’s knee, has similar evidence. Rotator cuff tendinopathy, plantar fasciitis, and Achilles tendinopathy all have meaningful research support for PRP.
In knee osteoarthritis, the research has shifted over the past decade. Earlier studies were mixed. More recent analyses, including several systematic reviews published between 2020 and 2024, have shown PRP to be at least as effective as hyaluronic acid injections and superior to cortisone at 6 and 12 month follow-up in mild to moderate knee OA. PRP appears to be a reasonable first-line injection choice in many cases of early to moderate knee osteoarthritis.
Hip osteoarthritis and facet joint pain in the spine have less conclusive evidence for PRP, though research is ongoing.
The Cost and Insurance Reality
The cost difference is significant and influences patient decisions. Cortisone injections are inexpensive and covered by most insurance plans when performed for approved indications. Copays are typically modest.
PRP is generally not covered by most insurance plans in the United States. It is an out-of-pocket expense, and costs vary by clinic, anatomic site, and whether ultrasound guidance is used. A complete treatment course may involve one to three injections spaced several weeks apart.
This cost difference is real and should factor into the decision. For some patients, the evidence for PRP in their specific condition does not justify the cost difference. For others, the evidence is compelling enough, and the concerns with repeated cortisone meaningful enough, that PRP is the better choice even out of pocket.
A clinic should be able to explain specifically what PRP is likely to do for your specific condition, based on the research, rather than presenting PRP as a universal solution.
How to Think About the Decision
For patients facing this decision, a few questions help clarify the choice.
Is this an acute flare or a chronic problem?
Cortisone is reasonable for acute inflammatory flares that need to be settled quickly. Chronic tendinopathy or early osteoarthritis is where the PRP case is strongest.
How many cortisone injections have you already received in this location?
If this would be the first injection in a new problem, cortisone is often a reasonable starting point. If this would be the third or fourth in the same joint or tendon, the concerns about cumulative tissue effects become relevant.
What is the underlying diagnosis?
Inflammation-dominant problems favor cortisone. Degenerative tendinopathy or cartilage-related pain favors PRP.
What are you trying to accomplish?
If the goal is to get through a specific event such as a vacation or wedding, cortisone’s rapid onset may be valuable. If the goal is to change the trajectory of a chronic problem, PRP’s slower but more durable mechanism may be better aligned.
Can you afford PRP?
This is a real question. For patients for whom PRP is financially out of reach, cortisone used judiciously remains a legitimate option. But for patients who can afford either, the choice should be made on clinical grounds, not cost.
The Case for Starting with PRP in Certain Conditions
For several specific conditions, the argument for starting with PRP rather than cortisone is strong enough that it should be seriously considered.
Tennis elbow in a patient who has not yet received a cortisone injection in that elbow. The comparative evidence favors PRP at long-term follow-up, and cortisone in this specific location has shown poorer long-term outcomes in some studies.
Early to moderate knee osteoarthritis in a patient who wants to avoid the cumulative effects of repeated cortisone. PRP has shown durability of benefit that repeated cortisone does not.
Chronic patellar tendinopathy, Achilles tendinopathy, and plantar fasciitis in patients who have already tried conservative measures and are weighing injection therapy.
For these conditions, starting with PRP, even at higher upfront cost, often represents better medicine than starting with cortisone and progressing through multiple injections.
When Both Are Appropriate, and When Neither Is
Some patients are well-served by both treatments, in sequence or in combination. A patient with acute severe pain from tendinopathy may benefit from an initial cortisone injection for rapid relief, followed by PRP several weeks later for underlying tissue repair. This combined approach is used thoughtfully in certain cases.
Equally important is recognizing when neither injection is the right answer. Patients who have not yet tried appropriate physical therapy, activity modification, or load management should generally work through those conservative measures first. Injections are adjuncts to, not substitutes for, the foundational work of rehabilitation. A patient who has never done structured physical therapy for a tendinopathy is unlikely to have better long-term outcomes from any injection than from committing to proper rehabilitation first.
Injections also are not appropriate for patients with active infection in the target area, certain bleeding disorders, or specific contraindications that should be identified during clinical evaluation.
What to Expect at Evaluation
A thoughtful evaluation for injection therapy involves a detailed history of the problem, a physical examination specific to the affected joint or tendon, review of any prior imaging, and sometimes additional imaging such as ultrasound or MRI when the diagnosis requires clarification.
The recommendation that comes out of that evaluation should be based on what is actually wrong, what has already been tried, what the research supports for the specific condition, and what the patient’s goals are. A clinic that recommends the same injection to every patient regardless of diagnosis is not practicing individualized medicine.
Momentum Medical offers both cortisone and PRP injections across our Central Florida locations. The decision about which treatment is right for a given patient is made in consultation and based on the full clinical picture, not a one-size-fits-all protocol.