Research:
A Cornerstone of

Orthopaedic Surgery

By Rita M. Rooney

Both bench and clinical research have long been the underpinnings of orthopaedic medicine, a discipline that continually probes new and better ways of repairing broken bodies, stimulating the regeneration of tissue and bone, and generally furthering advances in surgery. Recently, orthopaedic studies have reached a remarkably promising crossroads in the development of the relatively new field of tissue engineering. They include technologies being developed at UMDNJ-Robert Wood Johnson Medical School, in the Department of Orthopaedic Surgery laboratories.

Charles J. Gatt, Jr., MD ’89, associate professor and chair, Department of Orthopaedic Surgery  has a sub-specialty in sports medicine, and has been conducting tissue engineering research related to torn meniscus, the most commonly injured part of the knee.

“Most orthopaedic surgeons today believe the future of surgery lies in tissue engineering strategies to replace tissue,” Dr. Gatt reports.

The technology employs the use of biocompatible materials, or polymers the body will accept. The materials are shaped as fibers and combined with a collagen sponge to serve as a scaffold or temporary device that ultimately stimulates its own replacement by the body.

“The meniscus is a C-shaped rubbery shock absorber that fits between the bones in the knees,” Dr. Gatt explains. “When it tears, we usually have to remove the torn part because the tissue generally doesn’t have the ability to heal. We’re trying to use tissue engineering technology developed at the medical school to repair this condition.”

Michael G. Dunn, PhD, associate professor of orthopaedic surgery, has developed a tissue engineering technique for replacing the primary ligament in the knee, and now he and Dr. Gatt are researching the potential of the same strategy applied to the meniscus.

“As it is today, by removing the torn part of the meniscus, we lose a big part of this shock absorber,” Dr. Gatt says. “Dr. Dunn and I are working to come up with an implant that will stimulate the regeneration of the meniscus. Currently, this can be done with a meniscus from a cadaver, but the results are only short term.”

Emphasizing his enthusiasm for the advances possible through tissue engineering, Dr. Gatt says that the current method of performing ligament reconstruction is to remove part of the patella tendon or hamstring tendons and use either to rebuild the torn ligament.

“Twenty years from now, we’ll look back and say there was never any reason to do that,” he says. “We’ll be able to implant something in the knee, and a new ligament will grow in its place.”

He points as well to numerous other applications for this relatively new science, and reports that the orthopaedic research laboratory is currently collaborating with Siobhan A. Corbett, MD ’87, associate professor of surgery, in research aimed at being able to use collagen sponges for repair of abdominal defects, such as hernia. He predicts that his laboratory soon will attempt to apply tissue engineering to the restoration of cartilage lost through trauma and arthritis. Tissue engineering may also play a role in replacing bone damaged by tumors. Instead of replacing bone with bone from other parts of the body, collagen or another biocompatible material could be used.

At present, Dr. Gatt and his colleagues are developing a prototype for the meniscus implant. They are studying a mixture of a collagen sponge reinforced by biocompatible fibers, and are trying to optimize the mixture of fiber and sponge to re-establish normal meniscus mechanics as closely as pos-sible. They want a material with the same properties as the original tissue. Once they have developed this mixture, they will do mechanical testing. After that, they will fabricate a full meniscus device for animal implantation.

“Meniscus tearing is a serious medical problem, resulting from trauma, the degenerative process, or a combination of both,” Dr. Gatt says. “It happens to older people with arthritis as well as to ‘weekend warriors.’ The implications of tissue engineering offer us a method to eliminate the resulting pain in ways never before possible.”

The Department of Orthopaedic Surgery was developed from the existing division of orthopaedic surgery in 2003, and its faculty consisting of an 11-member surgical team, is one of the most prestigious orthopaedic services in central New Jersey, and one staffed by physicians representing most sub-specialties within orthopaedic medicine. Joseph P. Leddy, MD, at the time a clinical professor of orthopaedic surgery, was appointed the department’s first chair; upon his recent retirement, Dr. Gatt was named chair. Prior to the creation of the department, the surgeons had served as volunteer faculty, responsible for teaching both medical students and residents.

“We consider this a perfect match, an opportunity for both the school and our group,” Dr. Gatt reports. “We brought with us a strong clinical practice. In turn, our surgeons enjoy teaching and wanted to expand their efforts in that direction. Perhaps most important, we looked forward to becoming more involved in research, benefiting from collaboration with colleagues at the medical school, as well as from the stature RWJMS gives to NIH funding applications.”

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