What Every Patient Should Know Before Having a Cortisone Injection.
If you’ve ever suffered from shoulder pain, knee arthritis, tennis elbow, heel pain, or another persistent musculoskeletal problem, chances are someone has suggested a cortisone injection at some stage. At SSPC, we are frequently asked whether cortisone injections are a good idea. When used appropriately, cortisone injections can be a valuable treatment option. The injection must be for the right problem, at the right time, and most importantly with the right rehab program and advice before and after it!
What Is a Cortisone Injection?
Cortisone is a corticosteroid medication with powerful anti-inflammatory properties. It is commonly injected into joints, bursae, or around irritated tissues to help reduce inflammation and pain. Conditions commonly treated with cortisone injections include:
- Knee & Hip osteoarthritis
- Shoulder bursitis & Rotator cuff-related shoulder pain
- Tennis elbow
- Plantar heel pain (plantar fasciitis)
- Severe spinal pain with neurological symptoms.
Many injections also contain a local anaesthetic, which may provide immediate short-term pain relief before the cortisone begins to work.
What Cortisone Does Well.
There is no question that cortisone injections can be effective at reducing pain and for people struggling with significant discomfort, this may lead to:
- Improved sleep
- Easier movement
- Greater participation in daily activities
- Reduced pain during exercise
- Improved ability to engage in physiotherapy
Sometimes pain becomes such a significant barrier that meaningful rehabilitation becomes difficult. In these situations, a cortisone injection can provide a valuable opportunity to begin moving more comfortably again.
But understanding what happens next is important.
The Biggest Myth: Cortisone Fixes the Problem.
One of the most common misconceptions is that if the pain has improved immediately after the injection, then the injury must be healing. Unfortunately, that isn’t true. A cortisone injection can reduce pain, but it does not directly repair damaged tissue.
For example:
- It cannot regrow worn cartilage in an arthritic knee.
- It cannot strengthen weak muscles.
- It cannot reverse tendon degeneration.
- It cannot improve fitness or conditioning.
- It cannot correct poor movement patterns.
What cortisone does is help manage the process of the symptom (inflammation) rather than addressing the underlying cause.
That doesn’t mean it isn’t useful. It simply means we need to understand its role correctly.
Pain Is Like an Engine Warning Light on Your Car Dashboard!
One of the simplest ways to understand cortisone injections is to think about a “Check Engine” light in your car. When the warning light appears on your dashboard, the car is telling you that something needs attention. The warning light itself is not the problem. It’s simply alerting you to a problem.
Now imagine if there was a button that could instantly switch off the warning light. The dashboard would be clear, we’d feel relieved, and we’d probably just keep driving on! But has the engine been repaired? Not necessarily – the issue that triggered the warning light may still be there.
Pain works in a similar way. Pain is your body’s warning system that something isn’t quite right.
A cortisone injection can often reduce the pain signal, by reducing the inflammation in the area, making you feel significantly better. In effect, it has helped switch off the warning light. But unless the underlying cause is addressed, the problem that triggered the warning light still exists. And carrying on with activity just because the pain is less, just like continuing to drive the car if you could switch the warning light off, is fraught with danger.
The real goal is not simply turning off the warning light. The goal is identifying and fixing the reason it came on in the first place.
What Cortisone Does – and Doesn’t Do!
- The goal of cortisone is to reduce inflammation (and therefore reduce pain), improve short-term function and most importantly it creates an opportunity to improve the results of your rehabilitation! Post cortisone injection, it is essential to continue working on the cause of your inflammation and pain, whether that cause be poor strength, loss of function, reduced endurance, lowered tissue capacity, lack of confidence, altered movement quality…or any other cause!
Cortisone Does Not:
✗ Heal tendon tears
✗ Repair cartilage damage
✗ Reverse arthritis
✗ Restore muscle strength
✗ Improve fitness
✗ Correct the underlying cause of pain
Understanding this distinction is one of the most important things patients can learn before having an injection.
What Does the Research Say?
Research shows cortisone injections can provide meaningful short-term pain relief for certain conditions.
However, long-term outcomes are often less impressive. There have been various studies on conditions such as tennis elbow, shoulder pain, plantar heel pain and osteoarthritis and these studies have shown that while cortisone injections may provide faster symptom relief initially, exercise-based rehabilitation often produces superior long-term outcomes.
In a fascinating trial which was published in the British Medical Journal, you can see the results in the graph below indicate that following a cortisone injection for tennis elbow conditions (blue dash line), the results are a lot better at 6 weeks post injection, but clearly not as successful as a wait and see (red line) or physiotherapy (green dash line) at the 12 month mark. By 6 weeks, the physiotherapy approach is not far off the cortisone outcome, but then steadily continues to improve in success score, when compared to the cortisone approach which rapidly declines in success between 6 and 12 weeks.
(Bisset, L., Beller, E., Jull, G., Brooks, P., Darnell, R., & Vicenzino, B. (2006). Mobilisation with movement and exercise, corticosteroid injection, or wait and see for tennis elbow: randomised trial. BMJ, 333(7575), 939. doi.org)
However, this doesn’t mean cortisone injections are ineffective. Rather, it highlights that:
following a cortisone injection, pain relief should ideally be combined with a rehabilitation strategy that addresses the underlying contributors to pain.
What About Arthritis?
Many people seek cortisone injections for knee or hip osteoarthritis. For some individuals, injections can provide significant symptom relief lasting weeks or even months. This can be particularly useful if pain is disrupting your sleep, daily activities are becoming difficult, exercise has become challenging, and flare-ups are regularly occurring. However, cortisone does not reverse arthritis! The strongest evidence for long-term arthritis management continues to support:
- Strength training
- Regular exercise
- Weight management
- Physical activity
- Education and self-management
These interventions improve the health and function of the entire joint system rather than simply reducing symptoms temporarily.
Are There Risks?
Like all medical procedures, cortisone injections carry potential risks. Possible side effects include:
Temporary Pain Flare
- Some people experience increased discomfort for 24–48 hours after the injection.
Skin Changes
- Occasionally, skin thinning or lightening may occur around the injection site.
Elevated Blood Sugar
- People with diabetes may experience temporary increases in blood glucose levels.
Infection
– Although rare, infection remains one of the most serious potential complications.
*Tendon Weakening
– Repeated injections around tendons may increase the risk of tendon degeneration or rupture. Cortisone is rarely, if ever, injected directly into tendon or muscle.
*Cartilage Thinning
– cortisone inhibits the cells that build and maintain collagen (which plays a crucial structure in the formation and structure of articular cartilage). Studies have shown that patients injected every three months for 2 years (which is a lot) showed measurable cartilage loss. In other words the repeated cortisones contributed more to the pathology it was trying to prevent!
Why Only 3-4 Injections per year (maximum)?
Other than the risks mentioned above, the effect of repeated cortisone is shown below:
1 injection per year: definite anti-inflammatory benefit with minimal structural risk to the area being injected.
2-3 injections per year: the beginning of suppression of the fibroblast cells that build collagen. There is also evidence of a reducing pain effect per injection.
4+ injections per year: the risks start to outweigh the benefits.
The Bottom Line
Cortisone injections are neither miracle cures nor a treatment to be feared. They can be highly effective at reducing pain and inflammation when used at the right time, for the right problem, and with the right rehab program. Cortisone injections should always be viewed as one component of a broader management plan rather than the entire solution.
The most successful outcomes nearly always occur when the temporary post injection pain relief is used as an opportunity to address the real drivers of pain through exercise, strength, movement, education, and rehabilitation.
My patients know that I love to use analogies in my explanations, so here’s my final message:
Cortisone may switch off the warning light … but rehabilitation helps fix the engine.
Anthony Lance
SSPC Physiotherapist
References available on request.
