Many adults (mostly women) between the ages of 40 and 60 years of age develop adhesive capsulitis (also known as “frozen shoulder”). This condition causes shoulder pain and stiffness when the normally loose parts of the joint capsule stick together. As you have probably found out, this seriously limits the shoulder’s ability to move, and causes the shoulder to “freeze.”
There are two separate schools of thought regarding treatment for adhesive capsulitis. Some experts suggest a home-based approach because eventually the problem corrects itself. Patients use pain relievers, moist heat, and simple exercises to keep the joint moving. Others recommend direct treatment to make sure patients regain normal motion and function.
Most experts agree that severe painful limitations of motion should be treated by a physical therapist. For patients with persistent pain, pain-relieving medications and steroid injections are commonly used in addition to physical therapy. But steroid injections have some disadvantages and some patients either don’t want them or can’t tolerate them. That’s when hyaluronic injections may be used instead.
Hyaluronic acid is a normal part of the matrix that makes up cartilage. It has two distinct properties that make it so important for smooth joint motion. It is both viscous (slippery) and elastic. The viscosity allows the tissue to release and spread out energy. The elasticity allows for temporary energy storage. Together, these two properties protect the joint, help provide joint gliding action (especially during slow movement), and act as a shock absorber during faster movements.
Some experts think hyaluronic acid (HA) injected into the shoulder has some additional benefits. They suggest that the HA reduces inflammation of the synovium (lubricating fluid inside the joint). It also has a direct effect on the pressure inside the joint to separate the joint capsule where it is stuck together. Hyaluronic acid may be protective of the joint cartilage and prevent the formation of adhesions that keep the capsule from the smooth gliding action needed for normal shoulder motion.
The question naturally arises — which works better: steroid or hyaluronic acid injections? Studies are being done to find out, so we don’t have a definitive answer on this yet. What we know so far is that hyaluronic acid injections are safe and effective for many people with knee osteoarthritis. Its use with shoulder problems like adhesive capsulitis is fairly new.
Results of treatment with hyaluronic acid in studies done so far are fairly positive using pain intensity, shoulder joint motion, and function as markers of success/failure. Studies comparing hyaluronic acid and steroid injections also report that everyone in both groups report less pain, better motion, and improved function.
One study comparing the two showed patients receiving three hyaluronic injections spaced out over a six week period of time had greater passive external shoulder rotation at the end of treatment. This might have occurred because the pressure from the hyaluronic acid opened up the joint space, which is needed to increase external rotation.
For patients who cannot tolerate steroid injections (or who don’t want them), hyaluronic acid injection may be a good alternative treatment approach. Likewise, patients with other problems that affect the soft tissues such as diabetes, hyaluronic acid injections may be a better choice.