Hyaluronic acid injections have increased for knee arthritis - despite recommendations against their use

In 2013, the American Academy of Orthopaedic Surgeons (AAOS) published updated clinical practice guidelines recommending against the use of HA injections for patients with knee osteoarthritis, citing a lack of high-quality data to support the effectiveness of this procedure. Despite this recommendation, "[W]e found that HA services continued to be widely implemented among this patient population," according to the new research by Atul F. Kamath, MD, of the Cleveland Clinic and colleagues.

Use of HA injections has increased – with advanced practice providers driving the trend

The researchers analyzed data on Medicare Part B claims to assess the utilization rates and associated costs of HA injections for knee osteoarthritis between 2012 and 2018. The study included data for an average of 11,169 providers per year.

Knee osteoarthritis is a very common condition and a leading cause of disability in older adults. HA injections are given with the aim of reducing pain and improving functioning by supplementing the fluid within the knee joint. However, as reflected by the 2013 AAOS guidelines, available evidence does not meet the minimum clinically important improvement thresholds for patients with knee osteoarthritis. In their study, Dr. Kamath and colleagues assessed whether and how this recommendation has affected the use of HA injections.

The data showed a significant increase in the overall use of HA services during the study period: from 1,090,503 services in 2012 to 1,209,489 in 2018. Consistent with the updated guidelines, the numbers of primary care physicians, rheumatologists, and orthopedic surgeons who provided HA services decreased after 2013.

In contrast, the number of nurse practitioners and physician assistants offering HA injections significantly increased. In an overall trends analysis excluding these advanced practice providers, there was no significant change in total use of HA injections.

Adjusted for inflation, costs for HA formulations increased from about $226 million in 2012 to $267 million in 2018. These costs increased among nurse practitioners and physician assistants, as well as pain and rehabilitation physicians.

The total costs associated with HA services increased from $290 million in 2012 to $325 million in 2018. Costs for services increased among nurse practitioners and physician assistants while decreasing among rheumatologists.

The AAOS recently released the 2021 version of its clinical practice guidelines. The new update reaffirms the recommendation against the use of HA injections, and actually 'downgrades' the recommendation 'due to a lack of generalized results.'

Further studies are needed to identify the value of HA injections for knee osteoarthritis and to determine which patients may benefit from this therapy, Dr. Kamath and colleagues believe. They add, "Similarly, future studies should evaluate the efficacy of specific interventions that can help limit inappropriate HA use among orthopaedic surgeons, advanced practice providers, and other health-care providers who manage knee osteoarthritis."