Stem cells may be used one day to mend or treat OA-damaged joints, or to create models that help test potential disease-modifying drugs or figure out how OA occurs, Dr. Tuan said. “The cells are really the true tissue engineers. We are just the coaches and cheerleaders,” he concluded.
OA Starting at an Earlier Age
People are getting OA earlier in many developed countries, said David Hunter, MD, PhD, a rheumatologist at Royal North Shore Hospital in Sydney, Australia. The median age of diagnosis is now around 56 years of age, he said. OA diagnoses will likely increase due to several factors. “We are all getting bigger!” he said. “Similarly, joint injury is also one of the biggest drivers for people getting this disease, along with obesity. We are not doing anything about these problems and we need to.”
Most of his OA patients want to delay or avoid surgery, Dr. Hunter said. Weight reduction to reduce load on joints, preventing OA, or slowing progression should be the first line of defense. Later, palliative strategies like analgesia or, if necessary, arthroplasty can be implemented, Dr. Hunter said.
Drugs now in development that are attracting attention for OA include antinerve growth factor antibodies like tanezumab (although phase III trials to treat OA pain were halted when some participants required joint replacements due to rapidly progressing disease despite symptom relief); bisphosphonates like zoledronic acid; calcitonin; and strontium ranelate. In the future, researchers will focus more on biomarkers that may reveal what patients are most at risk for OA, Dr. Hunter said. These genetic clues, the subject of research efforts by groups like the Biomarkers Consortium of the Foundation of the National Institutes of Health, may indicate signs of OA years before symptoms develop or radiographic evidence is detectable, Dr. Hunter said.
Most of all, rheumatologists must focus on the whole patient in OA, as well as the whole joint, Dr. Hunter concluded. “We are not just interested in cartilage, but OA’s effects on bone, muscle, synovium, and also cartilage. If we do, we are likely to have much more meaningful results,” he said.
Susan Bernstein is a freelance medical journalist based in Atlanta.