As sports physiotherapists, we’d love to believe that every case of runners’ knee can be successfully treated and resolved with conservative care alone (exercise therapy, gait retraining, foot orthoses etc…).
However, the reality is that occasionally some runners continue to struggle with their knee pain, despite our best efforts. This is exactly when we need to start considering injection therapy for runner’s knee.
When should I consider an injection for Runner’s Knee?
The simple answer here is two-fold:
- After a period of time has passed with no improvement in pain (six weeks is a good rule of thumb).
- If your pain levels are both severe and irritable, and affecting your daily activities.
Let’s break that down a bit more…
There is rarely a quick fix for runners’ knee. In fact, most conservative treatments don’t work overnight. As a rule of thumb, after six weeks of what we consider to be consistent treatment and good compliance from the runner (doing their exercise homework), we start to consider if we should be considering an onward referral for, amongst other treatment options, injection therapy.
At times, runners present to us with high levels of patellofemoral pain. All types of pain are complex and individual, but if I see a runner who has highly severe and irritable knee pain from the outset, I’d be thinking about injection therapy much quicker in these scenarios.
What type injection should I consider for Runner’s Knee?
There are typically two injections that we consider for runners’ knee: either corticosteroid (often referred to as Cortisone) or hyaluronic acid (sometimes referred to as Ostenil or Durolane).
A word of caution…
I would never advocate injecting someone without an MRI scan. This is because the decision of what to inject has to be driven by what we see inside your knee.
We should only consider a steroid injection if there is active inflammation in your knee joint. This doesn’t have to mean that there is visible swelling that we can see; rather the presence of active inflammation of the tissues inside the knee.
If you put steroid inside a knee where there is no inflammation, the best-case scenario will be that there’s no real improvement, the worst-case scenario would be an increase in pain.
Hyaluronic acid should be considered when we see no real inflammation on MRI scan, but perhaps some widespread cartilage degeneration.
Without an MRI scan, there is no way of knowing and so PLEASE be wary of anyone offering to inject you without diagnostic imaging first.
How does injection therapy work?
Put simply, a steroid injection is basically a big dose of anti-inflammatory.
It will not solve the underlying problem, but (in the right runner) can be a very useful way of providing acute pain relief in the short term to allow other treatments to be effective.
The easiest way to think about hyaluronic acid is to view it as a lubricant.
Hyaluronan is a naturally occurring substance in joints, which often drops as we age and degenerative change starts to occur.
Typically, we consider hyaluronic acid injections in older runners, but we also use them in younger runners with no inflammatory signs on MRI.
Are there any risks to injection therapy?
In the right hands, the risks of either injection discussed above are very low.
Infection occurs in around 1 in 10,000 patients.
Blind injections carry slightly greater risks of pain, as we cannot guarantee exactly where the substance is going, so injecting under ultrasound guidance is best.
With steroid injections, there is a very small risk of a ‘steroid flare’, which is where a significant increase in pain is observed after the injection.
This risk is usually much lower when an injection is performed after an MRI scan and when an injection is performed using ultrasound guidance.
Regardless of what injection we choose, we advocate a one-week period of active rest afterwards before considering a return to exercise.
In conclusion, if you have a stubborn case of runners’ knee that is proving resistant to rehabilitation, or a very acute, painful case of runner’s knee, then injection therapy may be required.
Injections cannot work on their own but can be a very useful treatment adjunct in the right runner.
As always, we would suggest that you seek the advice of a quality physiotherapist or sports doctor if you feel an injection may help you recover.