NEW YORK—July 9, 2009
“The data has been encouraging to support further evaluation of this synthetic scaffold as a cartilage repair technique,” said Asheesh Bedi, M.D., a fellow in sports medicine and shoulder surgery at Hospital for Special Surgery who was involved with the study. Dr. Bedi performed analysis of MRI scans of patients primarily treated by Riley Williams, M.D., director of the Institute for Cartilage Repair at Hospital for Special Surgery. “The Trufit plug has been designed to have mechanical properties that are similar to cartilage and bone,” Dr. Bedi said.
Damage to so-called articular cartilage can occur in various ways, ranging from direct trauma in a motor vehicle accident to a noncontact, pivoting event on the soccer field. “Articular cartilage lacks the intrinsic properties of healing - you are essentially born with the articular cartilage that you have,” Dr. Bedi said. Left untreated, these injuries can increase loads placed on the remaining intact cartilage and increase the risk of progression to degenerative arthritis. One way to treat patients with symptomatic chondral lesions is an OATS procedure, in which cartilage is transferred from one portion of the knee to treat another. Because this is a “robbing Peter to pay Paul” situation, researchers at Hospital for Special Surgery set out to examine whether they could use a biodegradable plug, the Trufit CB plug, to fill the donor site. The goal was to monitor how the plug incorporated itself into the knee and to evaluate the quality of the repair cartilage.
The Trufit plug has two layers. The top layer has properties similar to cartilage and the lower layer has properties similar to bone. The bilayered structure has mechanical properties that approximately match the adjacent cartilage and bone. Surgeons inserted the plug in the knees of 26 patients with donor lesions from OATS procedures and followed up with imaging studies (with MRI and T2-mapping) at various intervals for a period of 39 months.
“Quantitative MRI, when combined with morphologic assessment, allows us to understand the natural history of these repair techniques and define those patients who are most likely to benefit from the surgery,” said Hollis Potter, M.D., chief of the Division of Magnetic Resonance Imaging, director of Research in the Department of Radiology and Imaging at Hospital for Special Surgery and lead author of the study. “We gain knowledge about the biology of integration with the host tissue, as well as the repair tissue biochemistry, all by a noninvasive imaging technique.”
“What we found was that the plug demonstrated a predictable process of maturation on imaging studies that paralleled the biology of their incorporation,” Dr. Bedi said. “With increasing postoperative duration, the repair tissue demonstrated encouraging properties with T2-values that resembled native articular cartilage.”
Dr. Williams, Dr. Bedi and other surgeons at Hospital for Special Surgery are involved in ongoing studies to investigate the efficacy of the TruFit plug in treating primary cartilage defects as well. “What is unique about this study is that we have serial MRI with T2 mapping at various time points after surgery, which allows us to really examine the natural history of plug incorporation,” Dr. Bedi said.
Dr. Williams believes that there is a role for scaffold-based cartilage repair strategies in the treatment of symptomatic cartilage lesions. “It is our hope that we can successfully treat these cartilage problems over the long term, thus restoring normal knee function and slowing the progression of knee arthritis,” Dr. Williams said.
Other authors involved in the study are Li Foong Foo, M.D., and the Cartilage Study Group.
About HSS | Hospital for Special Surgery
HSS is the world’s leading academic medical center focused on musculoskeletal health. At its core is Hospital for Special Surgery, nationally ranked No. 1 in orthopedics (for the eighth consecutive year) and No. 3 in rheumatology by U.S. News & World Report (2017-2018). Founded in 1863, the Hospital has one of the lowest infection rates in the country and was the first in New York State to receive Magnet Recognition for Excellence in Nursing Service from the American Nurses Credentialing Center four consecutive times. The global standard total knee replacement was developed at HSS in 1969. An affiliate of Weill Cornell Medical College, HSS has a main campus in New York City and facilities in New Jersey, Connecticut and in the Long Island and Westchester County regions of New York State. In 2017 HSS provided care to 135,000 patients and performed more than 32,000 surgical procedures. People from all 50 U.S. states and 80 countries travelled to receive care at HSS. In addition to patient care, HSS leads the field in research, innovation and education. The HSS Research Institute comprises 20 laboratories and 300 staff members focused on leading the advancement of musculoskeletal health through prevention of degeneration, tissue repair and tissue regeneration. The HSS Global Innovation Institute was formed in 2016 to realize the potential of new drugs, therapeutics and devices. The culture of innovation is accelerating at HSS as 130 new idea submissions were made to the Global Innovation Institute in 2017 (almost 3x the submissions in 2015). The HSS Education Institute is the world’s leading provider of education on the topic on musculoskeletal health, with its online learning platform offering more than 600 courses to more than 21,000 medical professional members worldwide. Through HSS Global Ventures, the institution is collaborating with medical centers and other organizations to advance the quality and value of musculoskeletal care and to make world-class HSS care more widely accessible nationally and internationally.