Opinion | Could There Be a Cure for Osteoarthritis?

Years ago, one of my patients injured her knee playing sports. She completed physical therapy, stayed active, did everything right. Osteoarthritis, a joint disease causing pain, stiffness and cartilage loss, found her anyway. She couldn’t understand why we could diagnose her osteoarthritis early yet couldn’t slow it down.

I’ve spent my career helping these patients: a grandmother who imagined a retirement full of travel, now planning every outing around parking and stairs. A patient in his 50s, told he was too young for a knee replacement, left to manage worsening pain while working on his feet all day.

Osteoarthritis affects 33 million Americans and more than 500 million people worldwide, costing the U.S. roughly $136 billion annually in medical care and lost productivity. As the population ages, this toll will grow: The number of annual knee replacements in the U.S. is projected to climb from more than 700,000 today to as many as 1.3 million by 2030. This is preventable suffering. Our default should be to preserve joints, not replace them.

The good news is that researchers are developing therapies that do what was once thought impossible: regenerate cartilage, boost the knee’s natural ability to heal, and prevent cartilage breakdown in the first place. The federal government’s Advanced Research Projects Agency for Health funds a program dedicated to this, called Novel Innovations for Tissue Regeneration in Osteoarthritis. We have science and funding. What’s missing is a regulatory system that evaluates whether these therapies work.

Many promising osteoarthritis treatments have stalled because the condition is slow-moving and unpredictable. It can take years to know whether a treatment is changing its course. Regulators have long relied on two tools to measure success: pain scores and seeing who eventually needs a joint replacement. Both are too subjective and slow, so new drugs often fail clinical trials not necessarily because they’re ineffective, but because the gauge measuring them is faulty.

New imaging and biomarker technology changes that. Advanced MRI scans can catch early signs of cartilage breakdown, long before a standard X-ray would. Blood tests can measure chemical signs of tissue degeneration to flag which patients may get worse. AI is helping researchers in spotting at-risk patients and tracking disease earlier, faster and more reliably than before.

The Food and Drug Administration has adopted these modern methods to approve new drugs for other slow-progressing diseases, including Alzheimer’s, osteoporosis and metabolic liver disease. Osteoarthritis already meets two FDA conditions for this pathway: It is a serious disease, and no current treatment stops its course. These new tools could let osteoarthritis meet the third condition: a surrogate endpoint, meaning an MRI scan or blood-test result likely to predict whether a patient’s joint is improving. By walking the same path they’ve already set for other diseases, the FDA’s regulators could give osteoarthritis patients a breakthrough in preventive medicine.

America’s population is aging, which means the number of people with osteoarthritis keeps rising. Every year we wait is another year of preventable pain and lost mobility for millions, and another year patients, employers and taxpayers spend paying to replace joints we might have saved.

Dr. Hunter is a rheumatologist clinician-researcher at the University of Sydney.