To Inject or Not to Inject?…That is the question.
Today’s post is a review of an article that I read yesterday and absolutely loved. The journal article’s content surrounded a very important question, debating a common topic among those in pain…Is it time to try an injection? Current evidence suggests that injections may be no more effective than non-pharmacological interventions such as physical therapy.
The shoulder is the 3rd most common site of musculoskeletal pain.
The most commons sources of shoulder pain involve the rotator cuff tendons and structures surrounding the subacromial (the acromion is the topmost part of the shoulder blade and forms the bony top of the outer shoulder) space. Due to the difficulty in differentiating between various causes of shoulder pain, “rotator-cuff related shoulder pain” (RCRSP) has become a widely used overarching clinical term encompassing a large number of conditions including subacromial impingement syndrome, subacromial pain syndrome, rotator cuff tendinopathy etc.
The most common method of treatment for RCRSP includes exercise, surgery, or injection therapy. 96% of musculoskeletal clinicians consider subacromial corsticosteroid injections an effective treatment for those suffering from RCRSP and recommend it to their patients….and 22% of those reporting shoulder pain receive an injection at their initial consultation. Many clinicians utilize injections as a first method of treatment, as well as a diagnostic tool by way of determining where symptoms arise from and if they’re on the right track.
Why would someone need an injection? What does it do? Your clinician would recommend a corticosteroid injection, commonly known as a “steroid shot” or “cortisone shot,” in an attempt to reduce the inflammation at that joint and in turn reduce or eliminate your pain.
What are they injecting?
Corticosteroid- Corticisteroids are a class of drug that reduced inflammation in the body. There are safety concerns surrounding the use of corticosteroids due to the potential for weakening or rupture of tendons. One study reported a 17% incidence of full-thickness rotator cuff tears at a 12-week follow-up visit post-corticosteroid injection.
Local Anesthetics- Examples include lidocaine and bupivacaine. They may have a therapeutic effect by altering tendon collagen organization and by reducing tenocyte numbers which contributes to the restoration of tendon homeostasis. Research shows corticosteroid injections may be favorable for short-term results, but that local anesthetic injections are not any less effective than corticosteroids in the mid to long term.
Sodium Chloride (Saline)- There has not been enough research conducted surrounding the efficacy of saline injections.
Platelet-Rich Plasma-This uses injections of a concentration of someone’s own platelets to speed up the healing of injured tendons, ligaments, muscles and joints. This injection is designed to specifically target tissue healing and address tissue pathology but there is a lack of evidence to make any clear suggestion of a benefit for the treatment of RCRSP.
Prolotherapy- This involves injecting specific concentrations of hypertonic (contains more dissolved particles than is found in normal cells and blood) dextrose solution around pathological tissue with the hope of sparking collagen synthesis and tissue healing. The mechanisms of action surrounding prolotherapy is not well understood, and further high-quality research is required comparing prolotherapy to other injections as well as other forms of conservative treatments to determine it’s efficacy and benefits.
Where do they inject?
Research demonstrates that the best place for the injection is into the subacromial-subdeltoid bursa or subacromial space. Studies have shown that intratendon corticosteroid injections can lead to structural disorganization, damage, and even tendon necrosis.
Interestingly enough, studies show no significant difference in RCRSP outcomes between subacromial and intramuscular buttock injections (both corticosteroid and local anesthetic); this demonstrates the ability to affect the shoulder joint through a systemic approach as well. Definitely food for thought.. but consider these conclusions cautiously…more research is needed in this area.
How do they inject?
There is a lack of consensus within the literature and among clinicians when comparing the reliability and accuracy of needle placement using landmark-guided injections verses ultrasound-guided injections. Despite the uncertainty, the majority of practitioners seem to be gaining interest and preference for the use of ultrasound to assist in guiding the needle to the correct spot. This would be a good question to ask your clinician prior to the procedure to learn more about their technique and why they prefer it.
Take away:
There is no clear consensus on the potential negative effects of corticosteroid injections on rotator cuff tissue.
The importance and role of inflammation in tendon pain are still widely debated and require further research.
Current evidence suggests that injections may be no more effective than non-pharmacological interventions such as physical therapy
Always explore all of your options before deciding on a form of treatment. Discuss your symptoms, concerns, past medical history, etc. with various clinicians from different disciplines in order to develop a well-rounded and complete understanding.
What works well for one person may not work well for you. Both clinicians and patients should remain cautious when considering the pros and cons of an injection due to the poor quality of research evidence.
Questions? Contact us! We’d love to chat!
Email: courtney@plusforte.co
Phone: 978-590-6951
Reference:
Cook T, Lewis J. Rotator Cuff-Related Shoulder pain: To Inject or Not to Inject? J Orthop Sports Phys Ther. Vol. 49, No. 5., 2019, pp. 289-293
