Tendinopathy (tendon pain) is very common. They are the most common type of overuse injury (ref). Achilles tendinopathy affects the majority of runners (ref) and is the reason 16% of athletes have to stop sports participation (ref).
There are a range of commonly prescribed treatment options for tendinopathy, but very few are supported by quality, randomised, prospective, placebo-controlled trials.
SO WHAT DO I DO?
Considering all the available treatment options, above anything else, I always recommend:
WHAT ABOUT INJECTIONS?
Having mapped out a management plan, patients will routinely ask my opinion on getting an injection. They may have had a friend for whom an injection worked well, or the GP has suggested it as an option, or they’ve had one before and it worked.
There are a range of drugs to inject into or around a tendon, depending on who you are referred to:
Corticosteroids are an anti-inflammatory medication injected around the tendon to decrease pain that is caused by inflammation (although it is now thought that inflammation does not play a significant role in tendon pain). Corticosteroid injections have historically been commonly prescribed but more recently their use is controversial. Repeated corticosteroid injections can weaken the tendon and increase the risk of rupture. Corticosteroid injections are good at relieving pain in the short term (2-6 weeks) however, there is strong evidence that long-term outcomes (> 6 months) are worse than other conservative treatments or no treatment at all (ref).
"The best systematic review evidence shows that local corticosteroid injections are not effective for tendinopathies after the first few weeks, and produce worse long-term outcomes compared to other treatments" (ref)
PROLOTHERAPY / SCLEROTHERAPY
Prolotherapy injections act as an irritant causing an inflammatory response then scarring of the nerves that transmit pain. There is no solid support in the medical literature for this procedure for the treatment of tendinopathies. A randomised controlled trial of polidocanol injections showed the potential to reduce tendon pain in patients with chronic painful mid-portion Achilles tendinopathy (ref). However, a systematic review found limited results for use of prolotherapy in sports related soft tissue injuries (ref).
AUTOLOGOUS BLOOD INJECTIONS
The rationale of autologous blood injection consists of enhancing tendon healing through collagen regeneration and the provision of cellular mediators. Good experimental models are lacking, and clinical application is anecdotal. A 2013 randomised controlled trial investigating the efficacy of autologous blood injections as a treatment for mid-portion Achilles tendinopathy concluded they did not reduce pain or improve function any more than a strengthening program. (ref)
The suggested mechanism of high-volume injections is the mechanical disruption of local tissues then stimulates a healing response. One study (ref) has shown that high-volume injection of normal saline solution, corticosteroids or anaesthetics reduces pain and improves short and long-term function in patients with Achilles tendinopathy. However, more research is required.
PLATELET RICH PLASMA (PRP)
Platelets are naturally occurring in your blood, where they play an important role in healing damaged tissue, so superficially it’s inherently appealing to just add more of them to the sore spot. PRP injections are particularly trendy at the moment and it’s easy to find someone who will tell you they work well. Unfortunately, research concludes there is no benefit to PRP injections. This study found PRP injections do not improve plantar fasciopathy pain or function. This study concluded there is insufficient evidence to support the use of PRP for treating musculoskeletal soft tissue injuries. This systematic review found strong evidence against platelet-rich plasma injections for tennis elbow. This study found PRP did not improve tendon structure. This meta-analysis found no greater clinical benefit of PRP over placebo or dry needling for tendinopathy.
Would I have any of these injections, or would I recommend them to my patients, friends, or family? Well it depends. In my experience some people get some benefit some of the time. HOWEVER, these injectables are not consistently effective and their use is mostly not supported by research. I suggest that patients try the strengthening program and the results will be overall better in the long term.
WHY DO THE INJECTIONS WORK FOR SOME PEOPLE?
I’ve been frustrated with a couple of patients that cancelled their follow-up appointment and, when I phoned and asked what had happened, they’ve had an injection and now feel fine. My conclusion is the injections don’t work, but if you were sore and now you’re not, your conclusion would be they do work. So what is it?..
REGRESSION TO THE MEAN
Most people seek treatment when they are at their worst. By definition the only possible change from being as bad as at can be, is an improvement. Was it the injection working, or was it getting better anyway?
Some conditions are self limiting and will just get better by themselves. Did the injection work, or was it about to get better anyway?
I understand that getting an injection seems like a much easier option than doing 12-weeks of strengthening exercises, but in the long run, a strengthening program is the thing that actually works.
If treating tendon pain was as easy as getting an injection then that’s what everyone would do first. Unfortunately it’s not as easy as that.
Adaptations to Training
When we “use” our bodies, our bodies adapt to the activity we are doing. The more we do, the more we are able to do. The less we do, the less we are able to do. This is essential in eliciting a training response.
When we train we want to cause stress to our body. (This may be our muscles, bones, cardiovascular system, etc.) We want to overload the system, which causes a degree of damage or micro-trauma. The body then responds by growing bigger / stronger / faster / fitter, so it can cope with that load in future. We cause stress to force adaptations.
Stress/load => damage => rest/recovery => adaptation/growth.
A lot of common gradual-onset injuries result from a failure to adapt to load.
There are a number of variables that can be multiplied to determine the total load:
The intensity of the activity is the most powerful multiplier in this list.
When we are considering total load, we also need to consider variables that make it harder for our bodies to adapt to load.
Variables that can be multiplied to determine how well we adapt to the load:
Recent research found that getting less than 8 hours sleep a day almost doubles the injury rate in athletes.