Are trigger point injection side effects real? Trigger points are problem areas in muscle that are in spasm (tight) and that no longer contract (weak). It used to be thought that they are caused by overuse, but it’s now known that they are instead neurologic (caused by the nerves that supply the muscles). These spots can cause pain which can radiate elsewhere, so treating these muscle knots can be important. At it’s least invasive, trigger point massage or deep tissue work can get rid of these spots. When that isn’t enough, a physician often performs a trigger point injection of local anesthetic and steroid. This practice began in it’s purer form in the 1960s with Janet Travell (who only injected a light anesthetic or nothing), but morphed through the years to use heavier anesthetics and anti-inflammatory drugs. However, is what’s being injected now OK for muscles? Not so much, according to a meta-analysis (a large review of many studies).
The large review paper looked at 49 studies that examined whether various substances commonly injected into muscles caused myotoxicity (muscle damage). The study concluded that there is strong to moderate evidence that intramuscularly injected local anaesthetics and NSAIDs (like Tordol) are myotoxic, and there is conflicting evidence of the myotoxicity of PRP. It also noted that steroid injections have a synergistic myotoxic effect when used together with local anesthetics. This is very concerning as this is a very common practice-adding in local anesthetics and steroids. They found no information to assess whether Actovegin® and Traumeel® are myotoxic. These are substances commonly injected by alternative medicine doctors, naturopaths, and chiropractors.
The upshot? Trigger points are a real problem for many patients. Since other studies have shown that there is little benefit to injecting anything (i.e. it’s the needle that does the work and not what’s being injected), then there really isn’t a rationale (outside of insurance reimbursement) to inject anesthetic nor steroid. In addition, trigger point dry needling or IMS is becoming more widely available in the US and elsewhere, so getting rid of trigger points really just requires an acupuncture needle. So you can skip the local anesthetics altogether!