Myofascial pain syndrome can cause severe pain and harm people's quality of life. That’s why clinicians are always looking for new and better options to treat this debilitating condition. Prolotherapy has been around for over 70 years and has been used to treat a variety of chronic musculoskeletal conditions. So do prolotherapy trigger point injections help treat myofascial pain syndrome? Two recent clinical trials attempted to answer this question.
Myofascial pain syndrome and trigger points are incredibly difficult to treat. That’s why I recommend taking a multi modal approach including a combination of using heat, exercise therapy including both cardio and resistance training, stretches, and soft tissue modalities including acupressure therapy with a foam roller or massage ball. But for people who have persistent pain, I recommend being even more aggressive with trigger point injections.
I’m going to review two recent studies that argue adding dextrose solution to the trigger point injection can significantly improve outcomes. The thought process is that dextrose injections lead to local inflammation in the tissue that mimics a tissue injury. This stimulates the body’s normal healing mechanism that leads to tissue repair and tissue remodeling and can result in both short and long term pain relief for patients with chronic musculoskeletal pain.
This first study was a retrospective case series of 45 patients with myofascial pain syndrome refractory to alternative treatments. The authors performed targeted ultrasound guided dextrose injections to treat chronic musculoskeletal symptoms that have persisted for more than one month. They injected 10 cc of 15% dextrose solution into the muscle fascicles and the perimysium between them. Injection sites included all major body locations including the upper extremities, lower extremities, and axial muscles.
The authors reported that the mean pretreatment visual analog pain score was a 7.0 out of 10 in the study group. At one month's follow up, the mean posttreatment score was 2.4 out of 10. 11 out of the 45 patients had reported complete resolution of their pain. Only 3 of the 45 patients reported no response or worsening symptoms. This suggests that 93% of patients had noted improvement after dextrose prolotherapy trigger point injection. Importantly, no adverse reactions or complications were reported following this intervention.
The authors go on to conclude that “targeted ultrasound-guided dextrose injection was remarkably effective for refractory localized myofascial pain syndrome. Injections significantly reduced symptom intensities in the majority of treated patients within 1 month after a single injection.”
This second study was a retrospective study of 57 patients with chronic posterior shoulder myofascial pain. All subjects had pain for at least 3 months and a visual analog pain score of at least 4 out of 10. They all had trigger points in either the infraspinatus muscle and or the teres minor muscle. All patients had persistent pain despite oral pain medications as well as physical therapy. The clinicians performed ultrasound guided dextrose injections using 10 cc of 15% dextrose solution and administered the solution into the targeted perimysium of the muscles.
The authors report that the mean pretreatment visual analog pain score was a 7.2 out of 10. The mean posttreatment visual analog scores at 4 weeks after injection were 1.9 out of 10. 19 participants were completely pain free while only 6 subjects did not notice any pain relief after treatment. This suggests that 91% of patients had noted improvement after dextrose prolotherapy trigger point injection. Only one of the 57 patients required a second injection. Just like the other study, no complications such as infection, allergic reaction, or bleeding were noted in any of the participants.
The authors go on to conclude that “ultrasound guided dextrose solution injection is an easy, safe, and effective injection method to manage posterior myofascial shoulder pain.”
So the thought process behind using prolotherapy injection is that dextrose can stimulate local inflammatory mediators and release growth factors. This can then facilitate tissue remodeling and subsequent symptom relief. This approach to treatment makes sense given our current understanding of the energy crisis hypothesis as the cause behind myofascial trigger points.
In brief, a trigger point causes a decrease in blood flow to the muscle. This results in an alteration to the biochemistry inside the muscle. This chemical imbalance leads to more contracture of the muscle leading to even more muscle tightening and muscle spasms. Tightening and spasm of the muscle then leads to even more restriction to blood flow and round and round we go through the trigger point pain cycle.
So dextrose prolotherapy injections can potentially help address the muscle chemistry imbalance as well as terminating muscle fiber contractures. Dextrose stimulates a local inflammatory response that stimulates tissue healing and muscle remodeling. By injecting this into the trigger point, we are potentially breaking the energy crisis cascade that leads to chronic pain.
So in theory this procedure makes sense. But what we really need are more clinical trials, ideally randomized controlled trials, to examine whether these treatments can truly help. In addition, both of these studies only reported outcomes at 4 weeks. This one month improvement can be truly life changing for people suffering from chronic pain, but what I’d like to see are long term outcomes as well.
At the end of the day, this is definitely a promising treatment for myofascial pain and trigger points and the great thing about it is that dextrose is very cheap and safe to use. It’s definitely something you’ll want to discuss with your healthcare provider about using if you are suffering from trigger points.
