A popular way to treat osteoarthritis (OA) of the knee is injections with hyaluronic acid (HA). HA is an important part of the normal synovial fluid in the joint. It helps lubricate the joint for smooth, gliding action.
How well do HA injections work? Is HA safe to use? Researchers in Taiwan compared the results of 20 other studies to find out. By combining the results of the studies, the authors were able to compare a large number of patients in each group. There were more than 800 in each group, for a total of 1,647 subjects.
All the studies had two groups of patients. One group received injections of HA into the joint. The second group also had injections, but they were placebos that didn’t contain any HA. Researchers used three categories of results to measure success. The categories were: 1) pain with activities; 2) pain without activities; and 3) function.
The authors found that HA may not work as well for patients over 65 years of age. Patients with severe OA didn’t do as well as those who still had some of the joint surface left. The authors conclude that doctors should consider patient age and status of OA before using hyaluronic acid to treat patients. Choosing the right patients for HA treatment will improve results.