According to McGowan Institute for Regenerative Medicine
faculty member Constance Chu, MD (pictured), a UPMC orthopaedic surgeon and director of the University of Pittsburgh Cartilage Restoration Laboratory, osteoarthritis is being diagnosed in people as young as age 20. Though most common in older adults, osteoarthritis – degeneration of the cartilage in the knee triggered by a breakdown of cartilage in a joint – may be caused by a widespread death of cartilage cells in the joint after an injury. In a study recently published, Dr. Chu, the Ferguson Endowed Chair in Orthopaedic Surgery at the University of Pittsburgh School of Medicine, found that trauma to a joint’s surface causes some of its cartilage cells to die instantly, and others to deteriorate within hours and days after the impact.
As noted in The New York Times Well Blog
, human knees are remarkable instruments, able to bear large loads and pivot in multiple directions. But they also damage easily, as evidenced by the approximately 175,000 anterior-cruciate-ligament (ACL)-reconstruction operations performed in the United States every year, a number that, by all estimates, has risen steeply in the past decade or so. Many of these operations are being done now on teenagers, who rip an ACL during a soccer or basketball game. (ACL operations were relatively uncommon in young people before youth sports grew so popular.) Others are in men and women in their 20s and 30s who fall on the ski slopes, for instance.
What has been less remarked upon is the concomitant growth, Dr. Chu says, in cases of exceptionally early-onset arthritis. Once a disease associated primarily with people past retirement age (and still most prevalent in that age group), osteoarthritis has been showing up in much younger people lately. “It’s not only in my practice,” Dr. Chu said. “Most orthopaedic surgeons are seeing very young people with very old knees.”
Not everyone who suffers an ACL tear or other serious knee injury develops early arthritis, of course. “Right now, a good guess is that about 50 percent” will have clinical arthritis “within 5 to 10 years” after the injury, Dr. Chu said (meaning, for a 15-year-old, by the time he or she is 20 or 25, and for a 30-year-old, probably before he or she turns 40). “That’s quite a large number.”
Dr. Chu and many other researchers across the country are trying to develop methods to determine which people will develop arthritis after a knee injury and why. “Many labs are interested in this question,” she said. But for the moment, no one has had much success.
Without sufficient, healthy cartilage within a joint, the bone surfaces will rub against each other, possibly leading years later to painful and debilitating arthritis. To address this issue, Dr. Chu is working to develop diagnostic techniques to identify patients who might develop arthritis after an injury, and to provide treatments that will preserve as much cartilage as possible.
Dr. Chu is one of only a handful of board certified orthopaedic surgeons conducting research funded by the National Institutes of Health. Her cartilage research program is recognized for innovative research integrating cellular and molecular biology along with advanced and novel imaging technologies to study cartilage degeneration, repair, and regeneration.
Illustration: McGowan Institute for Regenerative Medicine.
University of Pittsburgh Schools of the Health Sciences Media Relations News Release (12/09/09)
The New York Times Well Blog (12/09/09)
Eldercare, Aging and Long Term Care Blog (12/09/09)
Bio: Dr. Constance Chu
Abstract (Progressive Chondrocyte Death After Impact Injury Indicates a Need for Chondroprotective Therapy. Michal Szczodry, MD, Christian H. Coyle, PhD, Scott J. Kramer, Patrick Smolinski, PhD, and Constance R. Chu, MD. The American Journal of Sports Medicine, December 2009, Vol. 37, No. 12, 2318-2322.)