New procedure bests standard of care for fixing damaged cartilage

February 8, 2012

A new study has demonstrated that a procedure wherein healthy cartilage is transplanted to fix an area of damaged cartilage (osteoarticular cartilage transplantation or OATS procedure) is superior to the standard of care for repairing cartilage defects. It is thought that fixing such lesions may ultimately help to prevent the onset of osteoarthritis, and get athletic individuals back to sporting activities reliably. The study by Hospital for Special Surgery researchers was reported at the annual meeting of the American Academy of Orthopaedic Surgeons, Feb. 7-11.

"Studies have shown that there is only about a 40% return to sport after the microfracture procedure which is the standard of care treatment in the U.S. Over 90% of patients return to sport with the OATS procedure, said Riley J. Williams, III, M.D., a at Hospital for Special Surgery (HSS) in New York City and senior investigator of the study. "For those who have isolated of the and are interested in a return to sport in a timely and predictable fashion, the OATS procedure, relative to microfracture, represents a better option."

For years, researchers have known that of articular cartilage, the soft lining or cushion at the end of bones, can lead to symptomatic osteoarthritis. The cartilage can be damaged from normal wear and tear or from a . Once the cartilage is damaged, it continues to deteriorate. Athletes with progressive are often forced to stop playing their sport of choice.

Over the years, researchers have developed a number of procedures for repairing cartilage in patients who range from roughly 16 to 50 years of age. The current standard of care is microfracture, an arthroscopic procedure that involves using a tiny pick to punch holes into the base of the damaged cartilage area. This promotes bleeding and allows to come to the surface of the damaged tissue. As a result, the cells then change into fibrocartilage cells and heal the defect. A study from the HSS Cartilage Registry showed that only about 40% of athletes return to sport after this procedure. "40% is such an abysmal rate of return to sport, which is why we keep looking for other repair methods to help our patients," said Dr. Williams, who is also director of the HSS Institute for Cartilage Repair.

Another more recently developed procedure is OATS, which involves transferring healthy cartilage tissue from one part of a person's knee to the damaged area. The transplanted graft includes cartilage and underlying bone and can be performed arthroscopically. A single plug of cartilage may be transferred or multiple plugs may be transferred in a procedure called mosaicplasty. Each plug is a few millimeters in diameter, and when multiple plugs are moved to the damaged area, it creates a mosaic appearance.

Several European studies have shown that the OATS procedure provides a higher return to sport and a longer lasting result, but HSS researchers wanted to verify the results in the U.S. population. "There is an essential difference between American sports and European sports. When you talk about European sports, you are really talking about soccer," said Dr. Williams, whereas most U.S. patients mostly participate in American football, basketball, running, as well as soccer.

To test the two procedures in the U.S. population, HSS investigators recruited 48 patients who had "potholes" in their cartilage in the area known as the femoral condyle, an area located at the end of the thighbone in the upper half of the knee. For the control group, the researchers identified 48 patients in the HSS Cartilage Registry who were matched for gender and underwent microfracture for a similar cartilage repair, same lesion size and location.

Clinicians evaluated patients prior to surgery and at one, two, three and five years of follow-up. They used a variety of tools commonly used to measure outcomes in patients undergoing these types of procedures. They used the short-form (SF)-36 health survey, a 36-question scale that includes a gamut of questions about general health and is widely used across all fields of medicine. They used two knee specific questionnaires: the international knee documentation committee (IKDC) scores and the Knee Outcome Survey (KOS). And they used the Marx Activity Level that is scored on a scale from 0 to 16 and gauges a person's ability to do four activities: running, cutting, decelerating, and pivoting.

They found no difference in the knee outcome surveys or SF-36 form, but they did identify significant differences in the Marx Activity Level. Patients who underwent the OATS procedure had higher scores than patients who underwent microfracture at one year from baseline (score 5.21 vs. 4.11), two years (7.29 vs. 3.71), three years (7.75 vs. 2.91) and five years (8.55 vs. 2.89).

"The Marx activity rating scale correlates directly to the amount of physical activity that you can do at the time of the assessment," said Dr. Williams. "Patients who underwent the OATS were able to do more sports and more athletic activities compared to the microfracture group at the same time point. We now have another procedure which is likely to result in a return to sport more predictably."

He said the results are not surprising given that the OATS repair results in a natural cartilage repair whereas microfracture results in a repair comprised mainly of fibrocartilage that has been shown to be biomechanically inferior to articular cartilage.

Dr. Williams is the head team physician for the Nets NBA basketball team and the Major League Soccer's New York Red Bulls.

Explore further: New research points to a possible gender link in knee injuries

Related Stories

New research points to a possible gender link in knee injuries

July 7, 2011
Gender may be associated with an increased risk of cartilage lesions in anterior cruciate ligament (ACL) injured knees, according to research being presented at the American Orthopaedic Society for Sports Medicine's Annual ...

Recommended for you

Fluid in the knee holds clues for why osteoarthritis is more common in females

June 26, 2017
Researchers have more evidence that males and females are different, this time in the fluid that helps protect the cartilage in their knee joints.

Biologics before triple therapy not cost effective for rheumatoid arthritis

May 29, 2017
Stepping up to biologic therapy when methotrexate monotherapy fails offers minimal incremental benefit over using a combination of drugs known as triple therapy, yet incurs large costs for treating rheumatoid arthritis (RA). ...

Drug for refractory psoriatic arthritis shows promise in clinical trial

May 24, 2017
In a pivotal phase-3 clinical trial led by a Stanford University School of Medicine investigator, patients with psoriatic arthritis for whom standard-of-care pharmaceutical treatments have provided no lasting relief experienced ...

Cross-species links identified for osteoarthritis

May 17, 2017
New research from the University of Liverpool, published today in the journal npj Systems Biology and Applications, has identified 'cell messages' that could help identify the early stages of osteoarthritis (OA).

Osteoarthritis could be prevented with good diet and exercise

May 12, 2017
Osteoarthritis can potentially be prevented with a good diet and regular exercise, a new expert review published in the Nature Reviews Rheumatology reports.

Rodents with trouble walking reveal potential treatment approach for most common joint disease

May 11, 2017
Maintaining the supply of a molecule that helps to nourish cartilage prevented osteoarthritis in animal models of the disease, according to a report published in Nature Communications online May 11.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.