Newswise — Led by Andreas H. Gomoll, MD, sports medicine surgeon at Hospital for Special Surgery (HSS), the study is looking at the effects on knee function of ReNu, an allograft product composed of human amniotic membrane and cells from the amniotic fluid. Organogenesis, who makes the product, is studying ReNu in a number of orthopedic applications. The use of placental tissue has a long history in clinical medicine, particularly for the treatment of burns, ulcers and other wounds.

In the new study, "Evaluation of the ReNu Amniotic Suspension Allograft after Marrow Stimulation in the Treatment of Osteochondral Defects", Dr. Gomoll and his colleagues will be injecting ReNu into the knees of eight men and women with chondral and osteochondral defects. Osteochondral defects of the knee simultaneously affect both the bone (osteo) and cartilage (chondral) in the joint, while chondral defects only affect the cartilage. These defects can result from an acute sports injury, chronic wear caused by excessive pressure on the joint or other factors such as a genetic predisposition. Over time, these defects can lead to diffuse cartilage damage in the joint, also known as osteoarthritis, a painful, debilitating condition with few effective non-surgical treatment options.

Patients in the pilot study will receive intra-articular injections of ReNu two and four weeks after standard of care arthroscopic surgery to stimulate healing of the defect. During this procedure, surgeons drill tiny holes into the bone at the bottom of the defect to allow blood cells to seep in from the bone marrow below and clot, with the hope that stem cells from the marrow will help produce a new layer of healthy cartilage.

"There are not that many stem cells in the bone marrow, which can compromise the quality of the repair tissue. While microfracture surgery has satisfactory results in the short term, they tend to worsen over time, especially in larger defects," Dr. Gomoll says.

The researchers will follow the patients periodically for the next two years, making assessments of joint pain and function. The primary outcome of the study is any change after one year of treatment in two validated measures that provide researchers with ratings of mobility, pain, ability to perform activities of daily life and other important aspects of joint function.

Secondary outcomes of the trial are changes in knee pain and function both at the one-year mark and after two years of treatment.

Patients in the trial will be between 18 to 55 years old. The study is open to both men and women; however, because the safety of many medications, including ReNu, on developing fetuses is unclear, participating women must not be pregnant; must be using birth control; be postmenopausal; have been surgically sterilized; or be sexually abstinent.  

Ideally, Dr. Gomoll says, the factors contained in ReNu will help stimulate the patients’ own stem cells. And because stem cells have anti-inflammatory properties, they will help create a more hospitable environment for healing.

"The goal is to improve the quality of the new tissue by calming the knee down and giving the patient’s own stem cells from the bone marrow a boost," he says.

In addition, Dr. Gomoll and Dr. Sabrina Strickland (sports medicine surgeon at HSS) just concluded a randomized controlled trial of ReNu for the treatment of knee arthritis.

"Interim 6 month data showed that treatment with Renu resulted in clinically relevant and statistically significant improvements in pain, symptoms and activities of daily living scores as compared to hyaluronic acid and saline," Dr. Gomoll said. At the six-month mark, significantly more patients who received injections of ReNu reported benefit than did those who received either sham injections or conventional care with viscosupplementation injections. If the approach succeeds over time, "it will be one more treatment option we have, especially for patients who are not great candidates for knee replacement"—such as the old and infirm, but even more importantly young, healthy people who worry that they will lose mobility with the artificial joint.

Organogenesis, based in Canton, Mass., provided funding for both studies.


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 ninth consecutive year) and No. 3 in rheumatology by U.S.News & World Report (2018-2019). 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.