Prolotherapy is a popular yet controversial injection therapy used widely in sports medicine and recently more in general practice, that involves the injection of a dextrose solution. Yes that’s right, sugar injected into the body to help treat a variety of ligament, tendon, muscle and joint pains. However despite lots passionate anecdotal evidence for its benefits, such as speeding up healing, quicker return to sport, and the ability to reduce chronic joint and ligament laxity, there is actually little robust research that supports it use, and even less on its long-term effects.
I have personally witnessed its growing popularity and widespread use in professional sport and in general practice, and I have even referred patients for these injections. But I have to question my motives for this, and in this article we will look at what are the benefits, the risks, the research and the future for prolotherapy?
When is prolotherapy used?
Prolotherapy can be traced back about a hundred years when doctors used to give irritants to help heal many things. But its modern use has really been going since the 1950’s. It was first called ‘sclerotherapy’ as it was thought to be a scar forming therapy, and has been growing in popularity, for the treatment of acute ligament injuries, where the ligament has undergone a mechanical failure leading to laxity but not rupture, these are commonly seen in sports with the ankle and the knee ligaments being the most commonly injured areas.
Ligament laxity after a injury can be present for a long time afterwards and in some cases can be permanent leading to chronic joint instability and cause long-term pain and loss of function. This often prevents a returning to activity long after the original injury has healed. So having a treatment that could speed up the healing rate, but also reduce ligament and joint laxity seems a very attractive prospect to any medical professional, especially those working in sport, where the speed of an injured player returning to play is often the main measure of your success.
So what does prolotherapy do?
Prolotherapy acts as a local irritant and so creates an increased inflammatory response, this increases protein synthesis and collagen formation and so increased cell proliferation. Prolotherapy is also thought to increase the infiltration of leukocyte (white blood cells) and macrophages (debris removers) as well as increase platelet-derived growth factor (PDGF) and interleukin-1β (IL-1β) (chemical building blocks) and so help improve a ligaments strength, mass, thickness and a trend toward an increase in cell number, glycosaminoglycan (protien), and water content. (source, source , source)
How is prolotherapy administered?
Injections of the irritant in solution are given in and around the injured ligament, joint or muscle over a course of a few weeks to a few months. The number, dosage and concentration of the solution used is not well described or explained. Many clinicians seem use their judgement and intuition dependent on the severity and size of the injury and the amount of laxity present. One of the major limitations of prolotherapy research is the lack of consensus or standardisation of dosages or protocols to administer the injections.
Three solutions are commonly used in prolotherapy D-glucose (dextrose), phenol-glucose-glycerin (P2G), and sodium morrhuate. D-glucose is thought to be the safest solution but with conflicting evidence on its effects, with studies showing increase cell proliferation (source) but others showing cell apoptosis (cell death) (source). P2G is thought to create a stronger inflammatory response, but phenol has been found to be toxic to some human cells (source) and can also block peripheral nerves in humans (source). Sodium Morrhuate is a an extract of cod liver oil and found to be toxic to red blood cells (source). All the prolotherapy injections I have seen used have been D-glucose, which seems not only to to be the safest with regards to toxicity, but also has the most conflicting effects.
How does prolotherapy feel?
Well the first thing to mention is that prolotherapy is painful, more so in some areas than others, I have seen grown sports men and women have injections in their lateral ankle ligaments, knee MCL’s and LCL’s, lumbar facet joints, SIJ’s, and even one poor soul having is symphisis pubis injected… three times… ouch! They ALL complained of increased pain and discomfort during, and after these injections.
Thats not really surprising as the irritant nature of the solution causes a local inflammation which obviously can cause pain and discomfort, in my experience this lasts anywhere from 24 hours, up to a week afterwards. Patients are advised to rest and take analgesia as required, but obviously not anti-inflammatory medications as this counter effects the work of the injections, they are also advised not to do any vigorous exercise or have any manual therapy during this reactive inflammatory stage. Once the pain and inflammation is settled the ligament or joint is reassessed for laxity and pain and either re injected or the rehab can begin
Are there any adverse effects to prolotherapy.
In the scant literature and in my clinical experience there are no significant side effects apart for a post injection flare of pain and some tenderness around the injection site. Rabago et al. 2010 did find some very rare effects such as allergic reactions and nerve damage but none classed as serious.
However I would like to add something here, about possible long-term detrimental side effect that prolotherapy may cause. It is purely anecdotal and based only on a single case, but it was observed in conjunction with a very senior and well-respected sports orthopaedic surgeon who regularly operates on many high-profile and professional sports men and women.
It was observed that during an operation on a chronic MCL injury in a professional footballer that had previously had four prolotherapy injections over two years ago, that the ligaments collagen structure was unusual and had changed. It was noted to be comprised mainly of soft stringy collagen, Type III, opposed to the normal stiffer more rigid collagen Type I. The orthopaedic surgeon doing the surgery also commented that this is not the first time he has witnessed this unusual collagen make up with other athletes who have had prolotherapy injections around ligaments, and then needed surgery.
The surgeon explained that he thought these prolotherapy injections may indeed help with protein synthesis and collagen formation, but he believes its of this softer less dense Type III collagen which is formed rapidly and quickly after the injections, which for a stabilising ligament isn’t the best type. He went on to explain that he thought this excessive Type III collagen produced by prolotherapy injections may well actually prevent the formation of normal Type I collagen from being laid down with normal natural healing mechanisms, and so could caused potential long term deficits.
Does prolotherapy work?
Well in my experience and from my own anecdotal evidence…
YES… and NO?
YES… There does seem to be a speedier rate of healing for acute ligament injuries, and ligament laxity does seem to improve very quickly. I have personally seen very lax MCL’s and ATFL ligaments with clear joint gapping on testing, have three to four of these injections over a 4-6 week period and the laxity reduces remarkably quickly and in some cases go completely. I have also seen players return to play a lot quicker than I would expect after ligament injuries, I would say around 30-40% quicker, so a six-week injury is back in four, not majorly important in general sport but a massive bonus in professional sport.
NO… However for those that I have seen go for prolotherapy for conditions such as chronic muscle, tendon or joint pains I would have to say I saw no major benefit. These injections for low back pain, possible facet joint pain and other joint issues such as osteitis pubis I would say didn’t achieve much?
But what about the research????
Well as mentioned there isn’t that much out there and most research has been done on animal models. Jenson et al. 2008 found that rat MCL’s did show ligament thickening after prolotherapy but no difference in its strength or any reduction in joint laxity.
Jenson et al. 2008 again in a different study found that prolotherpay did produce an increased inflammatory response in rats that could assist in cell proliferation, but this was not significantly different from injections of saline solution or just needle stick trauma.
Kim et al. 2011 showed prolotherapy helped reduce chronic SIJ pain better than corticosteriod injections but it was a small study and its results cannot be generalised to the wider population
Cusi et al. 2010 again showed good results in SIJ pain but again cannot be generalised as only individual case studies and no control group
A systematic review done by Dagenais et al. 2007 showed conflicting effects and no effect of prolotherpay when used alone in the treatment of low back pain
And finally another systematic review by Rabago et al. 2005 found limited results for use of prolotherapy in sport related soft tissue injuries and further high quality research with non injection controls is needed
Would I recommend prolotherapy???
Hmmm tricky one… possibly YES and definitely NO… confused… so am I
Possibly YES… in professional sport I think it has a role to play in getting an injured player back quicker with minimal risk. But this has to be used wisely, I think it should only be used for acute ligament injuries that show clear laxity, not just the strains. I also think the player should be fully informed of the lack or research and possible side effects, ie it will hurt like a bugger afterwards, and the possible effect it can have on the ligament in the long-term as mentioned earlier.
In my experience most athletes wont give a toss about the long term effects, most are focused on getting back as soon as they can. This is the ethical dilemma many healthcare professionals have, a duty to weigh up the pro’s and cons’s of an intervention, verses the desires, beliefs and expectations of a patient, and this can be extremely difficult in a professional sports environment.
And definitely NO… I don’t think there is any role for prolotherapy, at the moment, in general musculoskeletal medicine and other non professional sports therapy until the evidence and research can show greater clearer benefits of these injections and prove that there is little to no detrimental long-term side effects to the ligaments and joints injected.
What do you think, have you come across prolotherapy and would you use it or have you used it and what results did it get you.
Thanks for reading and as always enjoy your sport