Osteoarthritis: 3 Things to Know

Sep 11, 2018

(1) Questionable efficacy of knee injections, (2) a dramatic increase in the prevalence of osteoarthritis, and (3) a promising molecular biomarker.

References1. Bedard NA, DeMik DE, Glass NA, et al. Impact of clinical practice guidelines on use of intra-articular hyaluronic acid and corticosteroid injections for knee osteoarthritis. J Bone Joint Surg Am. 2018;100:827-834. doi: 10.2106/JBJS.17.01045.2. Park J, Mendy A, Vieira ER. Various types of arthritis in the United States: prevalence and age-related trends from 1999 to 2014. Am J Public Health. 2018;108:256-258. doi: 10.2105/AJPH.2017.304179.3. Rivas F, Zahid OK, Reesink HL, et al. Label-free analysis of physiological hyaluronan size distribution with a solid-state nanopore sensor. Nature Communications. 2018;9:1037. Published March 12, 2018.

Highlights from three recent studies include: (1) evidence-based recommendations have led to changes in the use of corticosteroid and hyaluronic acid injections for patients with knee osteoarthritis; (2) the prevalence of osteoarthritis has more than doubled over time; and (3) new nanotechnology detects hyaluronic acid, a molecular biomarker for osteoarthritis.^1-3 Scroll through the slides for the latest findings and their clinical implications.

Recent updates in evidence-based clinical practice guidelines reflect questions about the efficacy of injections for knee arthritis. Guideline revisions based on new evidence have stopped or reversed trends toward increased use of injections for knee osteoarthritis, yet these treatments remain commonly used.

In an analysis of an insurance database from 2007 to 2015 of 1,065,175 patients with knee osteoarthritis, 405,101 (38%) received a corticosteroid injection and 137,005 (12.9%) received a hyaluronic acid injection.¹ By 2013, there was new evidence showing no benefit of hyaluronic acid compared with inactive placebo, which prompted a strong recommendation by the American Academy of Orthopaedic Surgeons (AAOS) against the use of this treatment. Hyaluronic acid injections decreased significantly among orthopedic surgeons and pain specialists, but not among primary care physicians or non-surgeon musculoskeletal specialists, such as rheumatologists or sports medicine physicians.

Clinical Implications: “Although the clinical practice guidelines did impact injection use, given the high costs of these injections and their questionable clinical efficacy, further interventions beyond publishing clinical practice guidelines are needed to encourage higher-value care for patients with knee osteoarthritis,” stated the researchers, led by Nicholas A. Bedard, MD, of University of Iowa Hospitals and Clinics, Iowa City. “We hope that this project helps to shed light on the important clinical practice guidelines created by AAOS and further encourages providers to follow these recommendations, share them with their patients, and utilize them as a guide to improve the value of care provided to patients with knee osteoarthritis.”

An analysis included 43,706 community-dwelling adults aged 20 years and older who participated in the 1999-2014 National Health and Nutrition Examination Surveys.² The age-adjusted prevalence of arthritis was 24.7%. Prevalence of osteoarthritis increased from 6.6% to 14.3%, whereas rheumatoid arthritis prevalence decreased from 5.9% to 3.8%.

The increase in osteoarthritis prevalence was significant in both men and women; in non-Hispanic whites, non-Hispanic blacks, and Hispanics; and in people with high socioeconomic status. Osteoarthritis was more common in older white women, which may result from age-related degeneration and hormonal changes.

Clinical Implications: “The increase in osteoarthritis with age is a consequence of cumulative exposure to risk factors and biological changes such as oxidative damage, thinning of cartilage, or muscle weakness,” said lead author JuYoung Park, PhD, associate professor of social work at Florida Atlantic University. “Because of these burdens, developing cost-saving and effective treatments is necessary to minimize arthritis symptoms, maximize functional capacity, reduce disability and, moreover, improve the quality of life for the more than 350 million people worldwide who are affected by arthritis.”

A new, quantitative method for the assessment of hyaluronic acid, a significant molecular biomarker of osteoarthritis, bridges a gap in conventional technology.³ Gel electrophoresis can be slow and messy, is semi-quantitative, and requires a great deal of starting material. Other technologies, including mass spectrometry and size-exclusion chromatography, are expensive and limited in range.

A solid-state nanopore sensor was used as a tool for the analysis of hyaluronic acid. This platform determined the size distribution of as little as 10 nanograms of hyaluronic acid extracted from the synovial fluid of a model of osteoarthritis.

Clinical Implications: Hyaluronic acid size distribution changes over time in osteoarthritis, so this technology could help better assess disease progression. “By using a minimally invasive procedure to extract a tiny amount of fluid-in this case synovial fluid from the knee-we may be able to identify the disease or determine how far it has progressed, which is valuable information for doctors in determining appropriate treatments,” said senior author Adam R. Hall, PhD, assistant professor of biomedical engineering at Wake Forest School of Medicine in Winston-Salem, North Carolina.