Hyaluronic Acid and Rotator Cuff Tendonitis
The treatment of rotator cuff tendinopathy typically revolves around a combination of a subacromial bursa corticosteroid injection and rotator cuff strengthening with physical therapy. Recently, studies have been looking at the role of hyaluronate in treating the symptoms of rotator cuff tendinopathy. Hyaluronic acid (HA) is naturally found in synovial fluid and is a high molecular weight polysaccharide (5). Repetitive mechanical stress across the shoulder can lead to tendinosis of the rotator cuff. This microtrauma can lead to adhesions, fibrosis, and necrosis within the tendon (1). Hyaluronic acid has been found to have antifibrotic properties, as well as anti-inflammatory effects (1). Studies have also found that HA injections can also upregulate vascular endothelial growth factor, which can accelerate tendon healing (4). Research has also found that low molecular weight (LMW) HA can act as an antioxidant and has the potential for free radical scavenging (3).
A) Low molecular weight hyaluronic acid is a well tolerated injection in to the subacromial bursa
B) Physical therapy has been found to be superior to hyaluronic acid injections in to the subacromial bursa
C) Hyaluronic acid can only be injected in to the glenohumeral joint as it will cause tendon degeneration with a subacromial injection
D) Injection of high molecular weight hyaluronic acid was found to be superior to low molecular weight hyaluronic acid in terms of pain relief
A recent study published in the Clinical Journal of Sports Medicine in November 2021 compared low and high molecular weight hyaluronate subacromial injections for the treatment of shoulder tendinopathy. The higher weighted hyaluronate weighs 2000kDa and the low weight HA between 80-800 kDa. Each group in the study was injected with either low or high weight hyaluronate into the subacromial bursa under ultrasound guidance. They found that both the low and high weight hyaluronate groups had reduction in short term pain control. They did not find a difference in efficacy between low and high weight HA (1).
Image 1. In plane visualization of ultrasound guided injection of the subacromial bursa.
Image 2. Demonstration of ultrasound guided glenohumeral injection.
Another study published in The Journal of the American Academy of Orthopaedic Surgeons compared the use of low molecular weight HA to physical therapy in patients with supraspinatus tendinopathy (2). They found that there was a greater improvement in pain at rest and with activity in the group receiving the low molecular weight HA subacromial bursa injection compared to PT.
In a similar study published in the Annals of Pharmacotherapy, researchers compared the role of high versus low molecular weight HA for rotator cuff tendinopathy. They found that at three months, there was a statistically significant improvement in pain in patients who received a LMW HA and HMW HA injection into the subacromial bursa (3). There was a slightly lower risk for inflammation at the site of the injection with the LMW group (3).
There have also been studies that have looked at mixing platelet rich plasma with hyaluronic acid and then injecting it into the subacromial bursa for the treatment of pain from partial thickness rotator cuff tears. A study published in Medicine & Science in Sports & Exercise compared four groups, where each received either a normal saline, HA, PRP, or HA + PRP injection (6). All of the injections showed an improvement in patient’s pain up to three months after the injection. However, the HA + PRP group showed the greatest statistically significant pain improvement at 12 months from the injection (6).
Further studies have compared HA to subacromial corticosteroid injections for the treatment of rotator cuff impingement. Published in the Journal of Shoulder and Elbow Surgery in 2021, this study compared a dexamethasone injection into the subacromial bursa for impingement verses a HA injection into the subacromial bursa (7). Both groups were found to have a statistically significant improvement in pain at 12 weeks, but the affect was more pronounced in the HA group (7).
Rotator cuff tendinopathy is commonly seen in a sports medicine practice and can be a challenge to settle down. Many conservative treatments exist but this review looked at the data regarding hyaluronic acid for rotator cuff tendinopathy. Studies support the use of low molecular weight hyaluronic acid injections as a safe and effective injection for rotator cuff tendinopathy.
Read more @ Wiki Sports Medicine: https://wikism.org/Rotator_Cuff_Tendonitis
Answer: A. Low molecular weight hyaluronic acid is equivalent to high molecular weight hyaluronic acid in terms of pain relief. However, low molecular weight hyaluronic acid was found to be better tolerated than the high molecular weight formulations. In studies comparing PT to HA both have been found to have improvement in pain with rotator cuff impingement but PT was not found to have a greater effect than HA.
1) Esmaily, Hadi, et al. “Subacromial Injections of Low- or High-Molecular-Weight Hyaluronate Versus Physical Therapy for Shoulder Tendinopathy: A Randomized Triple-Blind Controlled Trial.” Clinical Journal of Sport Medicine: Official Journal of the Canadian Academy of Sport Medicine, Nov. 2021. PubMed, https://doi.org/10.1097/JSM.0000000000000988.
2) Rezasoltani, Zahra, et al. “Low Molecular-Weight Hyaluronic Acid Versus Physiotherapy for the Treatment of Supraspinatus Tendinopathy: A Randomized Comparative Clinical Trial.” The Journal of the American Academy of Orthopaedic Surgeons, vol. 29, no. 19, Oct. 2021, pp. e979–92. PubMed, https://doi.org/10.5435/JAAOS-D-20-01014.
3) Mohebbi, Rezvaneh, et al. “High- Versus Low-Molecular-Weight Hyaluronic Acid for the Treatment of Rotator Cuff Tendinopathy: A Triple-Blind Randomized Comparative Trial.” The Annals of Pharmacotherapy, vol. 55, no. 10, Oct. 2021, pp. 1203–14. PubMed, https://doi.org/10.1177/1060028021994297.
4) Flores, César, et al. “Efficacy and Tolerability of Peritendinous Hyaluronic Acid in Patients with Supraspinatus Tendinopathy: A Multicenter, Randomized, Controlled Trial.” Sports Medicine – Open, vol. 3, no. 1, Dec. 2017, p. 22. PubMed, https://doi.org/10.1186/s40798-017-0089-9.
5) Honda, Hirokazu, et al. “Hyaluronic Acid Accelerates Tendon-to-Bone Healing After Rotator Cuff Repair.” The American Journal of Sports Medicine, vol. 45, no. 14, Dec. 2017, pp. 3322–30. PubMed, https://doi.org/10.1177/0363546517720199.
6) Cai, Y. U., et al. “Sodium Hyaluronate and Platelet-Rich Plasma for Partial-Thickness Rotator Cuff Tears.” Medicine and Science in Sports and Exercise, vol. 51, no. 2, Feb. 2019, pp. 227–33. PubMed, https://doi.org/10.1249/MSS.0000000000001781.
7) Kim, Yang-Soo, et al. “Does Hyaluronate Injection Work in Shoulder Disease in Early Stage? A Multicenter, Randomized, Single Blind and Open Comparative Clinical Study.” Journal of Shoulder and Elbow Surgery, vol. 21, no. 6, June 2012, pp. 722–27. PubMed, https://doi.org/10.1016/j.jse.2011.11.009.