Do Cortisone Shots Really Help Knee Arthritis? What the Latest JAMA Trial Tells Us

The Promise of a Shot

For millions of people suffering from the chronic pain of knee osteoarthritis (OA), the question is always the same: “Can a cortisone shot fix this?” The idea of a simple injection that can melt away swelling and pain is incredibly appealing. For years, intra-articular corticosteroid injections, commonly known as cortisone shots, have been a go-to solution for physicians and a beacon of hope for patients. They are powerful anti-inflammatory agents that, when injected directly into the knee joint, can provide a quick and often significant reduction in pain.But in medicine, as in life, quick fixes often come with a complicated story. The use of cortisone shots for knee OA has recently undergone a major re-evaluation, thanks to a landmark clinical trial that fundamentally changed how clinicians and patients should think about them.

Published in the prestigious Journal of the American Medical Association (JAMA), the McAlindon et al. trial was a game-changer. For the first time, researchers didn’t just look at how much pain relief a cortisone shot provided; they looked at the long-term structural effects on the knee joint itself.
The study was a randomized, double-blind trial that enrolled patients with painful knee OA. One group received a cortisone injection of 40 mg of triamcinolone every 12 weeks for two years, while the control group received a saline placebo. The investigators used a gold-standard approach, measuring both pain levels using a validated scoring system (WOMAC scores) and the actual cartilage volume in the knee using highly detailed MRI scans.
The results were both expected and alarming.

• No Long-Term Pain Benefit: As expected, the cortisone group reported better pain relief in the first few months. However, by the end of the two-year study, the pain relief was no different between the cortisone group and the placebo group. This confirmed what many clinicians already suspected: the pain relief from these shots is short-lived.
• Accelerated Cartilage Loss: This was a groundbreaking and alarming finding. The group that received repeated cortisone injections experienced a statistically significant loss of cartilage volume compared to the placebo group. In simple terms, the injections may have sped up the degeneration of the very joint they were intended to help.

Why this mattered so much: It was one of the first large, long-term trials to directly test the structural effects of repeated cortisone use. Prior research had focused almost exclusively on short-term pain outcomes, creating a misleading picture of their overall safety and efficacy.

The JAMA trial sparked a wave of new analyses and a re-examination of decades of data. The consensus that has emerged is a mix of good and bad news. Multiple systematic reviews and meta-analyses consistently show that intra-articular corticosteroids provide clear short-term pain relief, typically lasting for two to six weeks. For many patients, this relief is significant and can be a welcome break from chronic pain. However, these reviews also show that the benefit wanes quickly and is often not clinically meaningful beyond six to twelve weeks. The potential for structural harm, as seen in the JAMA trial, is a major concern. Corticosteroids are powerful anti-inflammatory drugs, but they can also affect the metabolism of chondrocytes, the cells responsible for creating and maintaining cartilage. Animal and some human imaging studies have suggested that repeated high-dose exposure could speed up cartilage thinning or alter the composition of meniscal tissue. ^[6] The exact risk is still under careful study and likely depends on the type of steroid, the dose, the frequency of injections, and individual patient factors. This is the core of the trade-off: a short-term, temporary benefit versus a potential for faster degeneration later.

The JAMA trial did not ban cortisone shots. Instead, it provided a clearer roadmap for their strategic use. These injections remain a valuable tool for a select group of patients, particularly those who:

• Have a severe flare-up of knee pain that is so bad it’s interfering with their daily function, work, or sleep.
• Need short-term relief to participate in a physical therapy program or to “bridge” the time before a planned surgery.
• Have been thoroughly counseled by their clinician about the risks, benefits, and alternatives.
• Understand that the goal is to use the shot sparingly and strategically, not as a long-term, routine solution. ^[3]

Guidelines from major bodies like the American Academy of Orthopaedic Surgeons (AAOS) and the American College of Rheumatology (ACR) generally recommend cortisone injections for short-term relief but emphasize their limitations and caution against frequent, repeated use. ^[4]

Your best plan for managing knee OA pain should be a multi-step strategy that prioritizes long-term health over short-term relief.

1. Start with the Foundations. The interventions with the strongest evidence for long-term pain reduction and slowing of progression are exercise and weight management. This is your foundation. A supervised strengthening and aerobic exercise program (like walking or cycling) and weight loss if you are overweight are the highest-value, lowest-risk treatments you can pursue. For managing flares, topical NSAIDs (like diclofenac gel) or a short course of oral NSAIDs are often the first-line medical options. ^[3]
2. Consider an Injection for Flares, Not Routine Control. This is where the cortisone shot fits in. Use it as a strategic tool to get you back on track. If a flare-up of pain is so severe that it prevents you from doing your prescribed exercises or getting out of bed, an injection can provide the temporary pain relief you need to return to your foundational therapies.
3. If an Injection is Chosen, Personalize It. When you and your clinician decide an injection is the right choice, you can maximize its effectiveness and safety. Using ultrasound guidance can significantly improve the accuracy of the injection. Furthermore, a discussion about the type of steroid and the dose may be appropriate, as some evidence suggests shorter-acting or lower doses may be preferred.
4. Pair the Injection with Rehab. The pain relief from a cortisone shot is a temporary window of opportunity. Schedule your physical therapy sessions and start a progressive exercise plan during the weeks after the injection. Use the reduced pain to build strength, improve mobility, and enable the behavioral changes that will provide long-term benefit. ^[3]
5. Reassess and Avoid Routine Injections. If your pain returns, avoid simply repeating the injection every few months. Reassess your situation with your clinician. It may be time to consider other options.

Beyond the foundational therapies and cortisone shots, other options are available. The evidence for these is mixed, but they may be considered in a personalized plan:

• Hyaluronic Acid Injections: These injections aim to supplement the natural fluid in the knee joint. The evidence for their effectiveness is mixed, but some patients report meaningful, long-lasting relief. Guidelines vary on their recommendation. ^[19]
• PRP (Platelet-Rich Plasma): In this procedure, a doctor draws your blood, separates the platelets, and injects them into your joint. The evidence is growing but still heterogeneous, with some trials showing promising results, but more research is needed. ^[23]
• Nerve-Targeted Procedures: For chronic pain that is unresponsive to other therapies, procedures like radiofrequency ablation can be used to target and block pain signals from the knee. This is a more advanced option with conditional recommendations from guidelines. ^[12]