Newswise — A pioneering clinical trial at Hospital for Special Surgery may offer a minimally invasive alternative for cartilage repair in the knee that uses the patient's own cells to repair the joint damage.

Arthritis is characterized by a loss or erosion of articular cartilage, which is the soft lining at the ends of bones. The arthritic process typically starts with damage to the cartilage surface, and can appear as a small hole or defect. Unfortunately as that damage expands, the chances of proper healing diminish as cartilage, the material that cushions the joints, cannot re-grow naturally.

"A small hole is going turn into a big hole eventually, given enough time," says Riley Williams, M.D., orthopedic surgeon, Sports Medicine and Shoulder Service, Hospital for Special Surgery in New York, and director of the Institute for Cartilage Repair at HSS.

After an initial injury that has caused damage to a specific area of the cartilage, there are few options that can repair the damage which is likely to lead to severe osteoarthritis. The most popular current treatment for such lesions is called the microfracture procedure. In this surgery, a tiny 'pick' spikes holes into the base of the damaged cartilage area to promote bleeding. This allows the patient's bone marrow cells to come to the surface of the damaged tissue. As a result, the cells then change into fibrocartilage cells and heal the defect.

While microfracture is minimally invasive and very quick, research has found that the defect may not always be fully repaired. The fibrocartilage does not hold up as well under everyday wear and tear as normal cartilage and has a much higher risk of breaking down again. As a result, surgeons in this area continue to pursue new methods of repairing cartilage injuries.

A new multi-center clinical trial led by Dr. Williams at Hospital for Special Surgery uses a patient's own cells to heal damaged cartilage, but in a much different way. First, a small piece of the patient's healthy cartilage is taken and then the cells are grown in a laboratory. These cells are put into a piece of protein matrix, called NeoCart®, which has an internal structure shaped like a honeycomb. The cells use the NeoCart® as a scaffold and begin to grow over and around the structure. This creates a piece of new cartilage which is then, through a tiny incision, implanted into the patient's joint over the damaged area, much like a living patch. The hope is that the new cartilage will repair the damage and integrate seamlessly with the surrounding cartilage.

"This operation is much shorter than previous similar procedures and is made through a very limited incision with much less pain," says Dr. Williams, who is also the official team physician for Major League Soccer's New York Red Bulls. "You're able to go in and, if not stop the arthritis, certainly delay its progress."

The trial is being held at six investigational sites around the United States and will test up to 30 patients between the ages of 18 and 55 to compare, on a randomized basis, the NeoCart® technology with the microfracture treatment. The data will be used to evaluate safety, the efficacy of the NeoCart® implant, identify appropriate patient populations and help inform future clinical trial design. Patients come back for follow-up visits after 10 days, six weeks, three months, six months, one year and then annually for the next five years. The NeoCart® procedure was developed by the Histogenics Corporation, located in Waltham, Mass.

Surgeons at Hospital for Special Surgery see cartilage repair as an area of growing need, with approximately 400,000 people in the United States suffering from cartilage injuries every year. This clinical trial is only one of several advances in cartilage repair and there is debate in the field on which approaches are most effective. In an upcoming medical symposium hosted by the HSS Institute for Cartilage Repair and directed by Dr. Williams on Friday and Saturday, December 5 and 6, the hospital will explore the controversy associated with the different treatments and will provide hands on demonstrations of the newest techniques and aids.

For the full program of the 2nd Annual Articular Cartilage Repair Symposium, please go to

For information about trial eligibility, please call Alana Burns at 212-774-2449 or email [email protected]

About Hospital for Special Surgery"¨Founded in 1863, Hospital for Special Surgery (HSS) is a world leader in orthopedics, rheumatology and rehabilitation. HSS is nationally ranked No. 1 in orthopedics and No. 4 in rheumatology by U.S. News & World Report (2008), and has received Magnet Recognition for Excellence in Nursing Service from the American Nurses Credentialing Center. In 2008 and 2007, HSS was a recipient of the HealthGrades Joint Replacement Excellence Award. A member of the NewYork-Presbyterian Healthcare System and an affiliate of Weill Cornell Medical College, HSS provides orthopedic and rheumatologic patient care at NewYork-Presbyterian Hospital at New York Weill Cornell Medical Center. All Hospital for Special Surgery medical staff are on the faculty of Weill Cornell Medical College. The hospital's research division is internationally recognized as a leader in the investigation of musculoskeletal and autoimmune diseases. Hospital for Special Surgery is located in New York City and online at