Hyaluronic Acid Injections Only for Some Knee Osteoarthritis Patients

For the first time, researchers have identified a potential predictive factor of failure by intra-articular injections of hyaluronic acid for knee osteoarthritis, researchers reported on June 9 at the annual meeting of the European League Against Rheumatism Annual Congress (EULAR 2016) in London.

Hyaluronic acid injections are widely used worldwide to alleviate pain and improve function in patients with mild to moderate knee osteoarthritis. However, physicians are often unable to predict whether or not the treatment will be successful. In most clinical trials, the rate of responders to treatment does not exceed 60 to 70 percent, researchers wrote in the abstract presentation.  [[{"type":"media","view_mode":"media_crop","fid":"49333","attributes":{"alt":"©TeresaLevite/Shutterstock.com","class":"media-image media-image-right","id":"media_crop_2686379583949","media_crop_h":"0","media_crop_image_style":"-1","media_crop_instance":"5944","media_crop_rotate":"0","media_crop_scale_h":"0","media_crop_scale_w":"0","media_crop_w":"0","media_crop_x":"0","media_crop_y":"0","style":"font-size: 13.008px; line-height: 1.538em; float: right;","title":"©TeresaLevite/Shutterstock.com","typeof":"foaf:Image"}}]]

Researchers, who were led by Florent Eymard of Henri Mondor University Hospital in France, conducted a post-hoc analysis of 166 patients from the intent-to-treat population of a controlled, multi-center, double-blind, randomized viscosupplementation clinical trial. The trial compared two hyaluronic acid in patients with symptomatic knee osteoarthritis. Patients received three weekly intra-articular injections of hyaluronic acid, and were classified as responders if they fulfilled OMERACT-OARSI criteria six months after injections.

In the analysis, Eymard and colleagues analyzed studies of 101 women viscosupplementation and 65 men, with a mean age of 65.2, a mean disease duration of 48.7 and a mean BMI 27.7. Forty-seven patients were obese, and 73 had grade 3 JSN. Before study inclusion, 95 had at least one VS or corticosteroid injection.

Sixty-eight percent of patients were identified as Responders. The researchers found that increased BMI and OARSI grade were significantly associated with lack of response. Similar associations, although not statistically significant, were found with previous IA HA or steroids injection and patients who were 65 years and older.

Multivariate analysis confirmed the association of obesity and radiological severity with lack of response. “We found a strong cumulative impact of potential predictive factors (age > 65, previous VS or steroid IA injection, obesity and severe JSN) on viscosupplementation response. All patients without predictive factors were responders, versus only 69.1 percent and 28.6 percent of those with 2 or 4 risk factors, respectively, researchers reported.

As a result, the researchers recommend that viscosupplementation should be considered in subjects with normal BMI and moderate tibio-femoral joint space narrowing. “This study shows, for the first time, a strong cumulative impact of potential predictive factors of failure. This can be helpful for clinicians when they inform patients on the chance of success of viscosupplementation,” they reported.

References:

Eymard F, Conrozier T, Chevalier X. “Predictive Factors of Failure of Viscosupplementation in Patients with Knee Osteoarthritis: Results of a Post-Hoc Analysis of a Double Blind, Controlled Non Inferiority Trial.” June 9, 2016. EULAR 2016. doi: 10.1136/annrheumdis¬2016¬eular.3415.